16 OB Baby Owners - How Many Are Left?

[Ghost]

For further clarity, let's not get confused by the messy transition from displacement behavior to planing behavior, where elements of both [displacement forces and planing forces] are significantly in play. Clearly, at 1 mph, the boats are basically lifted by traditional displacement forces only. By 25 to 30, they are, for practical purposes, lifted by planing forces only. The real transition from displacement to planing gets rolling between maybe 8 and 18 mph. But we need not define the messy transition, rather we just need to know that by 25 or 30 mph THE LIFT THAT IS BATTLING THE WEIGHT, AND THUS iS DICTATING RIDE HEIGHTS, COMES FROM PLANING FORCES, NOT FROM THE TRADITIONAL DISPLACEMENT FORCES THAT WE OBSERVED WHEN THE BOATS WERE AT REST.

Do you follow me this far, and agree so far?


I do not agree, there is a "battle" between lift and weight and that battle is moving in tandem as speed increases. The issue with the battle is what are the proportional elements of "lift" versus "weight".

What are the proportional contributions of each at ..............

30mph =
50mph =
65mph =
75mph =
84mph =

LOL, no offense, but what are you even talking about?

In the battle between lift and weight, the "proportional" contributions of each are 100% of each, at every speed you list, and at every other speed as well. With the boat running at a steady attitude on flat water, 100% of the weight is ALWAYS matched exactly against 100% of the lift. The force of lift equals the force of weight. If not, the boat would either be accelerating upward or downward. This is truly the most rudimentary physics--it is utterly indisputable. I hope we can agree on that because if not, this (read: you) is utterly hopeless, trying to make a boat faster with eye of newt and wing of bat. ;)

(Now, it is true that the air pressure against the hull is likely providing a little bit of net lift, but we're not even looking at that--neither of us has been talking about aerodynamics at all. So, there is a different question altogether, beyond the scope here, about how small is the small fraction of lift coming from air pressure rather than water pressure. Or whether the net effect of air against the hull is perhaps pushing it downward rather than upward. This is far more important with cats, designed to trap air to generate significant aerodynamic lift. So, for clarity, please acknowledge that we're only considering hydrodynamics and not aerodynamics.)

Circling back to my prior post, are you telling me that above 30 mph, you somehow believe that there is any significant contribution of traditional displacement forces to the total lifting force? You actually believe buoyancy is providing a significant fraction of lift when a boat is well up out of the hole at 30 mph?! If so, then what did you even mean when you agreed we don't need to define the messy transition when a boat is climbing out of the hole? The very definition of the messy transition is that it is the place where lift is a MIX of buoyancy and planing force. Below the messy transition, it's all traditional displacement (aka: buoyancy). Above the messy transition, it's all planing force.

It's utter nonsense to say you agree that we don't need to define the messy transition where buoyancy and planing forces combine to provide the lift, only to turn around and ask for the relative contributions of each to lift, at a whole bunch of speeds, all the way up to 84 mph. In so doing, you are claiming it is ALL a messy transition from displacement force to planing force, AND you are asking me to define it at a bunch of data points. LOL!

[Morgan's Cloud]

While you guys are sweating the details ,and I'm enjoying it to say the least , I keep hearing this little question buzzing around in my brain .
It asks , do you think a C16 could do 84mph with a 99 cubic inch outboard of maybe 170hp ?

[Greg Guimond]

While you guys are sweating the details ,and I'm enjoying it to say the least , I keep hearing this little question buzzing around in my brain .
It asks , do you think a C16 could do 84mph with a 99 cubic inch outboard of maybe 170hp ?


Ghost we agree to disagree. Holy crap, I totally forgot about that MC! Actually the first thing we need to answer is can the 1967 #452 16 do 68mph with a 205hp fishin motor? :eek:

[Ghost]

Ghost we agree to disagree.

LOL, we don't agree to disagree--if you explain what you are claiming perhaps we can agree to disagree. Are you claiming there is a significant mix of buoyancy forces with planing forces contributing to lift when boats are up running on plane at 30mph and above?

IF so, please explain what buoyancy forces actually ARE in your mind, because I think it's evident that we must be defining them differently or you are missing something pretty obvious. Or both.

Are you claiming that the proportion of buoyancy forces and lift forces is something other than 100% and 100% in the battle of lift versus weight? You said:
I do not agree, there is a "battle" between lift and weight and that battle is moving in tandem as speed increases. The issue with the battle is what are the proportional elements of "lift" versus "weight".


I don't even know what that is supposed to be asking. if you are asking for percentages of some elements which make up lift and some OTHER elements which make up weight, how about starting by saying what the elements OF LIFT and those OF WEIGHT actually are? Identifying what they are would go a long way toward figuring out how much of each exists at a given speed. FWIW, I identified two elements of lift: traditional displacement and planing force. At 30 and above, it's essentially 100% planing force and 0% buoyancy. IF you disagree, define what buoyancy forces actually are, because we MUST be talking about different things. Honestly, it sounds like you are at times actually confusing WEIGHT (a downward force, due to gravity) with BUOYANCY (an upward force), as if the two were the same.

EDIT: one last point. You said the battle of lift and weight is "moving in tandem as speed increases." What is that supposed to mean? Lift and weight are EQUAL with the boat running level. They are also UNCHANGING, but for negligible weight loss from instantaneous fuel burn off. They don't move with speed at all, as you suggest. They do the opposite: they actually stay the same with speed, precisely the reverse of what you said.

[mattyboy]

with the weight placement in hull 452 and the raised x yes i think 68 is a real number in the local salt water

the issue i have with lou's story is

no hp rating has been confirmed for his setup

no confirmation on if the ss had the slick lower or the stock shifting lower ( that's a real biggy)

this is now cemented in my mind

your 235 hp rude bolted to the back of a baby with the longer strakes( which we all feel are good for 3 or so mph) could only get to 61 mph your the OB guy would 300 get you to 70 in that setup?? what hp would get you to 84 in that setup 400???? how much hp can be rung out of a 99ci two stroke?? 350hp ???and when it is tweaked that much how user friendly and reliable is it??


if there was a 16 setup by a racer that was a daily 84 mph boat in the mid 70's and it ran for 20 yrs it would have come to the attention of someone in and around the hi po boating world and would have surely been recreated YET EVEN WITH THE ADVANACED TECHNOLOGY ALMOST 20 YRS AFTER LOUS' ENGINE FRIED NO ONE HAS COME CLOSE TO 84 IN AN OB 16

[Greg Guimond]

While you guys are sweating the details, and I'm enjoying it to say the least, I keep hearing this little question buzzing around in my brain. It asks, do you think a C16 could do 84mph with a 99 cubic inch Outboard of maybe 170hp?

Actually, there are four questions to fill in before the big one lol .........

1. Can a 16 with a 275hp I/O and an AQ 290 do 59mph?
2. Can a 16 with a 275hp I/O and an AQ 280 "E-drive" do 64mph?
3. Can a 16 with a 1998 Evinrude V6 (205hp) O/B do 68mph?
4. Can a 16 with a 2004 Mercury V6 (225hp) O/B do 75mph?


:welcome:

[mattyboy]

Actually, there are four questions to fill in before the big one lol .........

1. Can a 16 with a 275hp I/O and an AQ 290 do 59mph?
2. Can a 16 with a 275hp I/O and an AQ 280 "E-drive" do 64mph?
3. Can a 16 with a 1998 Evinrude V6 (205hp) O/B do 68mph?
4. Can a 16 with a 2004 Mercury V6 (225hp) O/B do 75mph?


:welcome:


1 NO that number is high
2 NO that number is also high due to the first number being high to start with
3 yes with weight shift and raised X
4 yes we have seen it on youtube but I have not seen anything to confirm it had no mods

[woobs]

Interesting....

My take:

1 Yes, 59 Mph is in the wheelhouse when the planets align.
2 No/Unsure, as that extra 5 Mph costs a lot of power the e-drive has to offset for.
3 Yes, If it's a 21" hull.... No, if it's a 55" hull
4 Yes if it's a 21" hull.... (it's documented). No, if it's a 55" hull.

However 21" hull has no bearing in a direct comparison to a 55" hull.

[Morgan's Cloud]

Actually, there are four questions to fill in before the big one lol .........

1. Can a 16 with a 275hp I/O and an AQ 290 do 59mph?
2. Can a 16 with a 275hp I/O and an AQ 280 "E-drive" do 64mph?
3. Can a 16 with a 1998 Evinrude V6 (205hp) O/B do 68mph?
4. Can a 16 with a 2004 Mercury V6 (225hp) O/B do 75mph?


:welcome:

Just attempting to boil it down to the simplest lowest common denominator , all techno reasoning aside.
(in my usual understated way :D )

If Dr Lou never existed and no one had ever heard of his claim what if someone today simply asked
'Is it possible for a C16 with a 99 cu inch 170hp engine to do 84 mph?'
I just have this feeling that the conversation would be much different .

[mattyboy]

Actually, there are four questions to fill in before the big one lol .........

1. Can a 16 with a 275hp I/O and an AQ 290 do 59mph?
2. Can a 16 with a 275hp I/O and an AQ 280 "E-drive" do 64mph?
3. Can a 16 with a 1998 Evinrude V6 (205hp) O/B do 68mph?
4. Can a 16 with a 2004 Mercury V6 (225hp) O/B do 75mph?


:welcome:

who knew it and when???

Again flawed reasoning . time is a big factor in all of these questions and to me at the heart of any truth in this whole thing.

lou's boat would have had to be rigged before Walin died so the timeline on that would be mid 1970's. Now can one believe that it could be setup to run 84 mph at that time so lou could buy it later and run 84 in 1996.

in the mid 70's 16 were being fitted with the 270 outdrive and powered by a 260 hp ford or a 300-330 hp chevy the 270 had no trim and with the props available at the time be low to mid 50's boats. some were fitted with the e drive and would be high 50's to low 60's boats. The 290 never was fitted on a 16 from the factory some of the last ones were fitted with the aq280 drive one or two were fitted with power trim. then the 16 skisporter goes away for good. the 290 is a product of the 1980's. I had my 16 with more than 300 hp,no trim and with a ton of old and custom props could not get any where near 59 mph until I applied current technology of the 2000's with the solas prop. Bills boat with the best prop of the day the 24 ultra and 260hp and trim only could get to the mid 50's after his resto. throwing 15 hp at a aq is like shoveling **** against the tide isn't going to net you anything.

The e drive was bolt on speed how much speed depended on your setup and finding a prop you could spin. keep in mind that volvo props were nothing but run about props. instead of making larger pitch props they used lower gears at first on the high hp apps. then the ultra came along a great prop at it's time, a lot of bow lift but with very high slip numbers that grow the faster you spin them. The e drive used merc props. the e drives were slim fast but the gears were weak and didn't survive in any great numbers.

your numbers for a 275 hp 16 would work for a merc alpha boat with trim and in place of the e drive use the alpha ss would put the 16 over 60 with 275hp but how far over not sure. but that doesn't happen until the 1990s

ok so now we move onto late 1990's and 2000's technology hull 452 has a worked motor with a jack plate and a weight advantage both placement and lack of over a volvo driven i/o 16 not to mention it has a more hydrodynamic lower than an AQ and it hits 68 mph.

then the 2004 merc running on a baby with longer strakes supposedly not modified just a fishing motor seen on youtube at 74 mph. I have never seen the lower on that boat and can't be sure it is not a wolf in sheep clothing . the more i think of this point right here the more i have to think that motor is no where near stock. you had a motor with 10 more hp on the same hull and were 13 mph slower??? Then it only goes to reason that a newer merc 300 with a speedmaster lower should well be able to come near 80 + mph have we seen this in the past , present??? or will we in the future?? but even if we did see it we still have not beat the numbers Walin has in his setup from the mid 1970's on a slower hull ???

I agree the baby shall not be used in this discussion again it has no bearing on this at all so throw your 4th question out

[woobs]

Matty, this sounds reasonable.

[Greg Guimond]

Matty, woobs, BUIZILLA, Morgan's Cloud, Just Say N20, and Ghost,

I'm still at 50% on 84mph. Direct question though, do you each agree that this picture proves 100% that at 65mph, if the inner strakes of a 16 terminated 46" forward of the transom, that those inner strakes would not be lifting the boat or in the ejection path of any keel water flow?

Simple enough question :smile:

[Ed Donnelly]

Matty; You stated "The e drive was bolt on speed how much speed depended on your setup and finding a prop you could spin. keep in mind that volvo props were nothing but run about props. instead of making larger pitch props they used lower gears at first on the high hp apps. then the ultra came along a great prop at it's time, a lot of bow lift but with very high slip numbers that grow the faster you spin them. The e drive used merc props. the e drives were slim fast but the gears were weak and didn't survive in any great numbers."

I was getting custom props for the E around the corner from me.. Brydon Brass in Rexdale on Brydon Rd.in the 70's
Depetre Kay Marine sp? in New York state were rebuilding E's with hardened parts in the 70's
Without these companies I would not have run over a 100 in my 16 back then...Ed

[Morgan's Cloud]

Matty, woobs, BUIZILLA, Morgan's Cloud, Just Say N20, and Ghost,



Simple enough question :smile:


Naah , Still not as simple as my question . :D

[Greg Guimond]

Matty; You stated "The e drive was bolt on speed how much speed depended on your setup and finding a prop you could spin. keep in mind that volvo props were nothing but run about props. instead of making larger pitch props they used lower gears at first on the high hp apps. then the ultra came along a great prop at it's time, a lot of bow lift but with very high slip numbers that grow the faster you spin them. The e drive used merc props. the e drives were slim fast but the gears were weak and didn't survive in any great numbers."

I was getting custom props for the E around the corner from me.. Brydon Brass in Rexdale on Brydon Rd.in the 70's. Depetre Kay Marine sp? in New York state were rebuilding E's with hardened parts in the 70's. Without these companies I would not have run over a 100 in my 16 back then...Ed

Big snowstorm coming into town. More time for keyboard controversy lol. What's up with the spammer.

Getting custom props (or any custom stuff) that would be a solid fit for the Donzi 16 OB#1 would have been no issue in the 1970's for Gerry Walin. If Ed D could get them so could others. In theory he bought the boat in 1965 or maybe 1966. The OMC Super Strangler was introduced to OMC race in 1971. It was enhanced several times over the years for race duty. Again, you have to remember that this guy was a factory signed driver, in a variety of boats for a decade from age 23 to 33. Of all the items that could have stopped a 16 from clocking 84 with OB power, the prop options are in my mind the least of the issues. Johnny Sanders was using unique stuff while he drove for OMC. Ron Hill was a driver before he went on to specialize in props and still does today with his son. Anybody recognize Bobby Herring? When I spoke with Jim Hallum he said they could pretty much make anything they thought was needed. Hallum was probably acknowledged as the best two stroke guy in the world for 25 years. Doc Jones shop was the AMG or Brabus of OMC. There are still several things stopping me from getting beyond 50%. Props aint one of 'em. Lou's note below claims he was prop riding. He would have been a solid driver to air it out that way but it's not uncommon with hi-po wackers.




From: 'Lou'
Date: Sat,15 Jun 2013
To: 'Greg'
Subject: RE:1965 Donzi 16 Question

Basically I bought the boat in '76 From Doc Jones when I was working at Bertram in Miami. It was Gerry Walin’s boat. It did 84 mph on GPS, at that speed only the prop was in the water.

[woobs]

Looks like we are taking another detour... but, I'll bite.

To me, "at that speed only the prop was in the water" sounds like he was speaking figuratively, not literally. But, that's a judgement call.

I'm certain special props were available in 1976 but, how do we know the prop used 20 years later when the 84Mph event happened (in 1996) was one of the original props and not a modern creation?

What is also puzzeling is that with a trailer full of props designed to work for this rigging (and described as more than all other racers commonly had onhand and available) Dr. Lou managed to find and keep the prop best suited to an absolute top speed run. This undoubtably made the boat suffer coming out of the hole and in the midrange as I'm sure specific racing props are designed for specific attributes. But we can definately argue props forever....without conclusion.

So, I have one question. Greg, how much horsepower do you thing this particular Super Strangler put out on that day in 1996 to go 84Mph? Simple. What's your number?

[Greg Guimond]

On the ponies I am still getting numbers together. There are some differences of opinion based some of the year changes. They ran from 1971 to 1976 which is a long time in the race world. On the props, you are correct, hard to say what Lou was running exactly 20 years later in 1996. I don't think the Gerry Walin trailer reference is much of an issue. Gerry was racing a bunch of different hulls over his years on earth, so he probably had a bunch on the rack based on the needs of the hull type and the race. Then the OMC race truck probably had more. I have a dozen hanging on the wall from fartin around. How many props Dr. Lou got in 1976, who knows, but I'm sure given Gerry had just taken his own life Doc Jones was probably looking to move on from the tragedy and unloaded what he had with the 16. One thing for sure, Lou could not prop ride with a 4 blade, too much paddle slap.

[Just Say N20]

I still don't believe it. A 16 is too heavy, and not areodynamically shaped to fly, which is what it would take to run 84 mph. Without a pad to run on to minimize wetted surface, I don't see it happening, even if that V4 had nitrous.

[Greg Guimond]

Let me try this again guys. Just trying to nail this detail down first ....... Matty, woobs, BUIZILLA, Morgan's Cloud, Just Say N20, and Ghost, anyone else who wants to avoid shoveling snow :(

Direct question, do you each agree that this picture proves 100% that at 65mph, if the inner strakes of a 16 terminated 46" forward of the transom, that those inner strakes would not be lifting the boat or in the ejection path of any keel water flow? No secret agenda.

[woobs]

I couldn't say 46" but the actual number is irrelivent anyways. Yes, I agree in this picture the inner strakes are not in the pressure area of the hull and they are out of the wetted surface. The water is running up the hull and being ejected by (and at) the outer strakes.

C'mon Greg... been waiting for your Super Strangler Hp number for a long time. What's your estimate?

[woobs]

In due respect, and I mean this sincerely, your getting everyone riled up here, and neither you, nor the Doc, have offered a single ounce of proof, which should have been thrown out there at the get-go

have Doc bring that boat to the Taveres event in 2 weeks and i'll be there, we'll find the best driver we can find, and have him see if it runs 84 in front of the oldest, most educated, tried and true, boat racers left on the planet, especially outboard racers....

I'll admit to some previous level frustration when coherent points have been discarded without proof to the contrary, and when conclusions are stated from estimations of seperate and different issues (or imagination).... but, I wouldn't say I'm "riled up".

The entire strake issue arose from the comparison with the Baby 16 at 74mph. After all it's just another 10mph to the promised land and, it seems in the ball park. BUT, I think we've proven that the long inner strake hull is not comparible (as Matty originally stated like, 400 posts ago) as the hulls are too dissimilar.

Bills 65Mph Ski Sporter hits closer to the mark as a comparison but again, with 430Hp and a big chunk of weight in the back it is very difficult to account for all the variables...try as we might.

This leads to the ride height issue where most of us believe that there is a limit where the boat will ride no higher in the water despite increased speed. This is because the lift produced from the water pushing up on the hull now equals gravity at that max height.

I'm not entirely certain the argument has been put forth that the force from AIR on the hull supplies the lift required to raise the ride to the point of riding only on the foot/prop. This would seem to support Gregs ride height theory of a lighter boat riding higher at faster speeds. Two issues here are 1.) The ability for the hull to be a lifting body (and at what speed that occurs) and 2.) How much power is required to basically FLY the 16 Ski Sporter Hull at a given weight.

So, Greg, do you mean to say the boat is prop riding? And How much power do you think the Super Strangler is producing to do this?

FWIW, I would say if you believe the power required to fly this boat really is there... We don't even have to consider 84mph anymore. :)
Oh, and the best proof is to re-create the event...(like I suggested hundreds of posts ago)

[Greg Guimond]

I'm not riled up BUIZILLA. Are you? I thought the intent of this board was to add discovery.

Dr. Lou made a lot of statements, like "only the prop was in the water". Not sure what he means exactly by that but in my book it means he was surfacing the drive fully.

Also, on the adding discovery to the board thingy. I thought it was interesting that the only 22 Classic O/B Donzi ever made ran twin Yamaha V6 Specials at one point. No one knew that. I thought it was interesting that Charlie Strang (who you basically insulted) was even willing to come back and add a bit of lure about having tested a Donzi himself. To me that is cool, who knows what it is to you. Mr. Strang is only a "Top Ten" most important person in performance boating history. I'm thankful that he replied.

[woobs]

Dr. Lou made a lot of statements, like "only the prop was in the water". Not sure what he means exactly by that but in my book it means he was surfacing the drive fully.

I do not know Dr. Lou but, I would not have taken that literally. He could just as easily have said; "it was really flying" and I would not take that to mean it was riding just the prop.In my book that means he felt he was going really fast (or as fast as he could go).

Building empirical data and drawing conclusions from someone's informal comments is not really the road to discovery.

So, stop stalling. How much power do you THINK the Super Strangler puts out?

[Greg Guimond]

This leads to the ride height issue where most of us believe that there is a limit where the boat will ride no higher in the water despite increased speed. This is because the lift produced from the water pushing up on the hull now equals gravity at that max height.

I'm not entirely certain the argument has been put forth that the force from AIR on the hull supplies the lift required to raise the ride to the point of riding only on the foot/prop. This would seem to support Gregs ride height theory of a lighter boat riding higher at faster speeds. Two issues here are 1.) The ability for the hull to be a lifting body (and at what speed that occurs) and 2.) How much power is required to basically FLY the 16 Ski Sporter Hull at a given weight.

I'm not certain how/if we can account for air lift as the boat is not a cat or a tunnel. About the only thing I can add here is that my 16 gets pretty sensitive to side gusts at speed. Not sure what that means when pointing into the wind, if anything.

If I used AIR in any way woobs I'd be labeled Hester Prynne for sure :embarasse

[woobs]

If I used AIR in any way woobs I'd be labeled Hester Prynne for sure :embarasse
Well, we know aerodynamic lift exists but I'm sure most of us believe it is not sufficient to generate meaningful lift in this instance and is probably insignificant. But, I'm trying to look for ways your position could be argued. If it's your argument...own it (and possibly be condemned by your peers)...or prove them wrong.

So, by your statement we'll all agree that AERODYNAMIC LIFT is so insignificant as to be irrelivent in this case.

We still need a power for the Super Strangler. It's the central part of this discussion and we have spent an awful lot of time dancing around it and moving to other factors that may or may not even relate to the question.

Give it up...what's your power number?

[mattyboy]

Matty; You stated "The e drive was bolt on speed how much speed depended on your setup and finding a prop you could spin. keep in mind that volvo props were nothing but run about props. instead of making larger pitch props they used lower gears at first on the high hp apps. then the ultra came along a great prop at it's time, a lot of bow lift but with very high slip numbers that grow the faster you spin them. The e drive used merc props. the e drives were slim fast but the gears were weak and didn't survive in any great numbers."

I was getting custom props for the E around the corner from me.. Brydon Brass in Rexdale on Brydon Rd.in the 70's
Depetre Kay Marine sp? in New York state were rebuilding E's with hardened parts in the 70's
Without these companies I would not have run over a 100 in my 16 back then...Ed

I guess i should have said merc splined and you could buy off the shelf stuff like mazco or merc stuff or go custom to fit your needs



my point was if you had a 21 pitch volvo prop on a 270 running near 50mph and you bolted up a e drive with a 21 pitch prop you gained a few mph and would be in the mid 50's I think the increases would be greater in a setup like bills.

[Greg Guimond]

woobs, Bill's photo shot of his 16 and then your sketch got me thinking .................

[Greg Guimond]

So I did some really bad drawing with some probably faulty geometry overlay ............. better than plowing the driveway in 10 degree cold :(

[Greg Guimond]

And then put the rough center of gravity balance line in for the 16. 75" is without motor (wacker or car) driver or gas tank (filled or empty) ..............

[Greg Guimond]

And then I went to try and start the cars, and plow the drive :banghead:

[Ghost]

http://www.youtube.com/watch?v=omApdPl0ovI

[woobs]

So I did some really bad drawing with some probably faulty geometry overlay

For what purpose? What point are you trying to illustrate?
What difference does a Cg make with NO engine?


Matty is right, and the weight distribution would make a difference. However, before we get there we have much bigger fish to fry. So I'd assume for the time being that the boat was rigged in a balanced configuration and that the angle of attack was trimmed to the optimum to reduce the wetted surface at WFO.

Where this leads is to how much area of the hull has pressure on it at 65mph and how much drag does that create. Try this..
http://www.scribd.com/doc/92551794/Planning-Hull-Hydrodynamics-Study-of-the-Effects-Caused-by-Variation-of-the-Thrust-Line-Due-to-Displacement-Series-62-Model-No-4667-1

This is all distraction from the question. what would help, is your power number for the Super Strangler. So....

[Greg Guimond]

I then put the rough center of gravity balance line in for the 16. 75" is without motor (wacker or car) driver or gas tank (filled or empty) ..............


For what purpose? What point are you trying to illustrate? What difference does a Cg make with NO engine? Matty is right, and the weight distribution would make a difference. However, before we get there we have much bigger fish to fry. So I'd assume for the time being that the boat was rigged in a balanced configuration and that the angle of attack was trimmed to the optimum to reduce the wetted surface at WFO.

Back inside, dang it's cold out there! Why can't I live in the Keys instead of lala land. When I have the stats on SS HP I will post it. woobs, on the Center of Gravity, 75" is only to show the starting point. Any engine you add will move the CG backwards, even with a driver and full 20 gallons of fuel never mind 1/4 tank. The question is how much MORE to the rear does the Center of Gravity go when fully rigged from 75"?
Somewhere in the board archive someone probably has the info for a 16 because your right woobs, big impact on wetted surface, even at only 5 degree angle of attack.


Our 1966 16 weighed in at 2476 no gas but engine and battery and it was a 289. we bought it new

[Trueser]

59 pages of this......

Ouch,

[Ghost]

59 pages of this......

Ouch,

A man was walking down the sidewalk one night when he came upon a boy, crawling around the base of a streetlamp. "Whatcha doin' there, sonny?" Asked the man.

"Looking for my quarter." replied the boy.

"Are you sure that's where you dropped it?" Asked the man?

"No" said the boy, "it was two blocks over. But the light is better here."

[Greg Guimond]

What difference does a Cg make with NO engine? Matty is right, the weight distribution would make a difference.

Here is the CofG with the motor and drive .......... from 75" down to 54"

[mattyboy]

not sure what stats you to figure the cog with the 4.3 but run your numbers with 258 lbs added at the stern and then add 300lbs or more depending on size of driver and fuel level fwd of the 75 inch naked cog point.

[Greg Guimond]

Here is the picture of my 16 when we put the sling to it showing 57". We could not "hang" the sandbags off the transom like a true wacker but close enough.

[Greg Guimond]

Actually, there are four questions to fill in before the big one lol .........

1. Can a 16 with a 275hp I/O and an AQ 290 do 59mph?
2. Can a 16 with a 275hp I/O and an AQ 280 "E-drive" do 64mph?
3. Can a 16 with a 1998 Evinrude V6 (205hp) O/B do 68mph?
4. Can a 16 with a 2004 Mercury V6 (225hp) O/B do 75mph?



Interesting....My take:

1 Yes, 59 Mph is in the wheelhouse when the planets align.
2 No/Unsure, as that extra 5 Mph costs a lot of power the e-drive has to offset for.
3 Yes, If it's a 21" hull.... No, if it's a 55" hull
4 Yes if it's a 21" hull.... (it's documented). No, if it's a 55" hull. However 21" hull has no bearing in a direct comparison to a 55" hull.


I'm cool with that Ghost but the focus is on how important 55s and 21s are. I'm saying that 55s are not in play at 65mph in an I/O and 21s are not in play at 75mph on an O/B powered boat. I wasn't sure earlier in the thread, but now I am confident. That said I am now at 60% confidence that Dr. Lou achieved 84mph in Miami 17 years ago racing Osiris Perez.

Question. Do you agree that 21s are not in play at 75mph?


Fair enough, and not sure on that question. Have to think on it, though my instinct is that 21s would be in play in almost any flavor of 16 at 75. But have to think more.

Ghost, curious if you thought more and have a feeling on whether the 21s are in play at 75mph?

[Ghost]

...Bill's Ski Sporter picture at 65mph shows that a CofG is dynamic while underway (his inner 55s are completely clear at 65mph) but 54" static Center of Gravity is a solid starting point while at rest.

RE: "center-of-gravity"


http://m.youtube.com/watch?v=G2y8Sx4B2Sk&desktop_uri=%2Fwatch%3Fv%3DG2y 8Sx4B2Sk

How does Bill's picture show that center-of-gravity is "dynamic" when underway?

[Greg Guimond]

Wow, Ghost you are right on that one. I am wrong. I guess it is not.

Do you think that the 21's are in play at 75mph? Also, what do you think about the 1967 #452 boat doing 68mph with only 55s? Can it go that fast with 210 horsepower?

[Greg Guimond]

not sure what stats you used to figure the cog with the 4.3 but run your numbers with 258 lbs added at the stern and then add 300lbs or more depending on size of driver and fuel level fwd of the 75 inch naked cog point.

Hard to believe that I was out on the boat on Decemeber 22 with the weather we have had. When we built my other 16 we did exactly what you are suggesting Matty. We used my weight of 190lbs and my 2004 outboards weight of 360lbs. The Center of Gravity only moved forward 3", from 54" forward of the transom to 57". My 16 build has a full floor under the bow and the forward deck is certainly heavier than the
1965 OB#1 would have been so that would equal your full 20 gallon tank of gas plus some, although I still doubt Dr. Lou was full of fuel if he saw 84mph. So in essence, I think the CofG's would be the same as
the I/O at 54". Now Bill's Ski Sporter picture at 65mph shows that a CofG is dynamic while underway, (edit: Ghost corrected me and this is not the case) his inner 55s are completely clear at 65mph, but 54" static Center of Gravity is a solid starting point while at rest. Also, remember that a heavier I/O will always sit lower in the water than the lighter O/B while underway.

I did a quick overlay drawing using the actual factory sketches instead of my chicken scratch and then laid over a very conservative 5 degree trim angle below .........

[Ghost]

Do you think that the 21's are in play at 75mph? Yes, still in play.


Also, what do you think about the 1967 #452 boat doing 68mph with only 55s? Can it go that fast with 210 horsepower? I don't know enough about it to know. Thougth I doubt it unless a LOT of stars lined up having to do with weight, drag, etc.

For some context, what's the point of all the questions about center of gravity? (AKA: if you found out it moved 2 inches here, 3 inches there, what would you hope to derive from that information?) Ultimately, all this is about trying to relate weight, power, and a few other things to speed, right?

Toward that end, I still haven't heard back on your definition of buoyancy forces, also known as traditional displacement forces. And how at, say, 30 mph and above, you seem to think there is any significant component of lift coming from buoyancy rather than from planing forces. You claimed that up around 55mph, something changed "hydrodynamically." I claim the real hydrodynamic change happens when getting out of the hole. Down near zero with these hulls, nearly all the lift is from buoyancy, and that by 30 mph, all significant lift comes from what can be considered planing force, not buoyancy.

Further, you were using this belief to explain your belief that two 16s with 6 inches of difference in transom waterline height at rest would almost completely maintain that 6 inches of difference in ride height up on plane. This is quite wrong, but if you were to follow through and understand the reality, it could only aid you in any other analysis. Among others, woobs went to great pains, as did I, to try to get you on the right track. In the same way that you have recently learned something about center of gravity, you might want to consider this point about planing forces even more. It has a LOT more to do with the math of what happens, and thus enters even more than COG into how you might estimate speed given weight/hp/etc. Not kidding.

[Greg Guimond]

On the misc other stuff, I don't have much more for you. Ok so Ghost you are not yet convinced that #452 did 68mph? Ok, a prop model and size will tell you a lot about that one if Matty is able to get that. Matty said the owner claims 205hp for that 20" Johnson. Those V6s turn 5400RPM I believe. On the inner strakes, I still do not believe that the 21s are in play with the lighter O/B powered 16 OB Baby that clocked 75mph when I look at the angles and the markings on the diagram. If those are wrong, I would be convinced otherwise. Maybe a few inches of the 21 inches at best, but doubtful even that as it is very hard to run a 5 degree attack angle as shown in the drawing.

I adjusted my speed numbers down a bit ..........btw the Merc 225 is a box stock 225 EFI, no mods.

1. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 do 55mph?
2. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 "E-drive" do 61mph?
3. Can a 1967 Ski Sporter 16 with a 1998 Evinrude V6 (205hp) O/B do 68mph?
4. Can a 16 with a 2004 Mercury V6 (225hp) O/B do 75mph?

Hmmmm ....... 55, 61, 68, 75 :eek!:

[Ghost]

On the misc other stuff, I don't have much more for you.

Its not that you don't have much for ME--it's you not having much for yourself. Rather than playing around with voodoo physics, you might want to learn a few things that help get closer to answers. Or not. The kid in the joke seems happy to look for his lost quarter the easy way and never find it.

You claimed earlier that you understood the forces in play very well, but it is clear that is not the case. Rather, what you understand is that:

other things being equal, lighter is faster
other things being equal, more powerful is faster
other things being equal, less drag is faster
lifting a hull with a sling, best to use a spacer bar so you don't crush it
cut out enough weight and drag, ala Colin Chapman, and you sometimes surprise the brute force crowd


Of course, any fool knows 1-3, and 4 has nothing to do with estimating boat speed. :)

5 is the only pertinent one, but it doesn't get anything QUANTIFIED on its own.

Where it gets harder, and more science is called for, is when other things AREN'T equal, and one must predict the net effect of pros and cons. It doesn't necessarily matter who you've talked to. My pet parrot could listen to the best minds in boat racing and come out saying "parasitic drag, rrrraawk" but it wouldn't mean he knew how to weigh factors in opposition to predict speed. Likewise a five year old could do the same, and could repeat some tips he'd picked up (like, 'lighter is faster'), but he wouldn't understand the WHY or HOW MUCH in order to make calculated predictions based on tweaks in design.

Honestly, if you want to start advancing your understanding, to make predictions that have any merit, I highly recommend going back to Woobs's drawings, to start. One showing areas of water pressure on a hull, one showing 4 main forces: thrust, drag, lift and weight. A boat hull WILL behave based on the net of all the forces pushing it. Running smoothly, lift WILL equal weight. Drag will pile up until there is no net positive thrust, and max speed will be reached. Running smoothly at full speed, the horizontal and vertical forces HAVE to net out to zero or the boat would be rising, sinking, speeding up or slowing down, or a combination of two. All of these forces are a mix of air and water pushing on the boat, except for the weight due to gravity.

We already agree we don't understand how the air is pushing on the boat. So, we're just looking at the water pushing on the boat. Woobs's drawings go a long way toward understanding that. Further, my persistent point about understanding.buoyancy versus planing forces is key to recognizing how your broken qualitative notion of ride height is yet another form of double-counting an effect, skewing the nonsense data toward your desired goal.

What would be awesome (bet it has been done, for sure) would be to have a hull with oodles of pressure sensors all over it, such that the picture of all the water pressures on a hull at speed could be measured, rather than calculated/estimated. Like understanding sailing dynamics using a sail covered in telltales. That would shorten and improve the hell out of threads like this.

Unless success is spending time not-finding a quarter. :)

Apologies if all that comes off as an affront, but just honestly trying to help your analysis.

[Greg Guimond]

Nicely structured Ghost, and I thought I was paid by the word lol. As a physics professor why don't you put all that scientific knowledge to use figuring out if the #452 can do 68mph with 205hp as the owner claims? Or telling me how the 21" inner strakes are in play at 65mph and above. Those two items I'd be happy to spend a quarter (after I find it on the wrong block) learning about. If I learn something from you, you can have The Mule for a week to break 80 :rolleyes:

Btw, and I'm sure you mentioned this already. Have you owned a 16? I'd be curious what model year and what you thought?

You probably run a Warlock :biggrin:

[Greg Guimond]

Oh and btw I brought forward drag as a key issue some time ago -


Two words for all you Dr Lou doubters and weedeater lurkers lol ........ "Parasitic Drag" :wink: I am now at 50% probability on 84mph. Will post some new info soon.

[Ghost]

Oh and btw I brought forward drag as a key issue some time ago -

Hence the parrot reference. :)

[Ghost]

Nicely structured Ghost, and I thought I was paid by the word lol. As a physics professor why don't you put all that scientific knowledge to use figuring out if the #452 can do 68mph with 205hp as the owner claims? Or telling me how the 21" inner strakes are in play at 65mph and above. Those two items I'd be happy to spend a quarter (after I find it on the wrong block) learning about. If I learn something from you, you can have The Mule for a week to break 80 :rolleyes:

Btw, and I'm sure you mentioned this already. Have you owned a 16? I'd be curious what model year and what you thought?

You probably run a Warlock :biggrin:

<Sigh>, the old "challenge the messenger instead of the message" fallacy.

[Ghost]

As a physics professor why don't you put all that scientific knowledge to use figuring out if the #452 can do 68mph with 205hp as the owner claims? Or telling me how the 21" inner strakes are in play at 65mph and above. Those two items I'd be happy to spend a quarter (after I find it on the wrong block) learning about. If I learn something from you, you can have The Mule for a week to break 80 :rolleyes:

Until basic concepts are agreed upon, applications and extrapolations of those concepts to specific parameters are utterly futile. One doesn't need to be a physics professor to understand that cog is essentially a constant. But one does need to understand that cog is essentially a constant to make any predictive analysis (of any use).

[Greg Guimond]

this is from the current owner of 1967 hull #452. on my question of the current setup:

"Hydraulic Steering, Gafrig Analog GPS Speedo, and I had a guy in Ft Worth hot rod a 1998 Evinrude 175 (because they are real slim) to about 200 horses and added a Jackplate and Bennett Trim Tabs. When I first rigged it I went 68 mph with a sexy prop without really trying. I just run a basic OMC prop now. I've got a few pics on this computer but most are down on the island. When I get back down I'll dig them up."

When John Bencoczy had his 16ob with the 175 Johnrude he told me it went 55-56 on a great day, no Jp, stock height and std fuel tank with an SST or Viper prop, there was another 16ob down here with a 200 Merc that ran right at 58-60, once again stock height and early Mirage prop, there was also a 16ob in Key Largo/Tavernier that had a 175 Black Max that ran about 57-58.


I recently restored a 16 OB. 1997 rebuilt 175 Johnson runs 54 mph WOT with 2 people on board -1/2 tank of gas.


Matty, did the current owner tell you what size prop he is running/ran for the 68mph on GPS?

The 1967 16 #452 (55s) is running 68mph with a 1998 Evinrude V6 with 205hp, yet John Benkoczy with a 1976 16 (21s) is only running 55mph with 30hp less. 30hp is worth about 3mph so the later model 16 OB Baby hull is actually 10mph slower. Same motor.

[Greg Guimond]

Here is the waterline comparisons for four different motors. The factory ad shot is running a 1972 Mercury 140. They weigh 309lbs. The Super Strangler weighs 258lbs.

[duckhunter]

Nothing pertinent to add, other than cool tower of power. Also, that chick has a bit of butterface going on.

[Greg Guimond]

Big ponies all around the blackjack table for what it would take Dr. Lou to lay down 84mph in 1996 in the 1600lb 1965 hull with a 15" Super Strangler ..........



I'm at 300hp to do 84mph at-will on any given day with a weedwhacker that will turn way up.


I'm at 280hp to 330hp to get to 84.


I still don't see it although the huge weight difference between a V8 and a Wacker makes a big difference. And for the record, I LOVED the V4 Super Strangler engines. Having said all that, I would say it would take at least 340 wacker hp to get to mid-80s.


I'm in at just under 300hp. Say, 295hp...to reach 84mph


on an unmodified 16 hull with 55s (short strakes) 330-350hp for an OB, say 340hp


at 1600# it would take a solid 275-280 hp at the prop at 6800-7000 rpm using a 13.25-13.5" dia wheel

[Greg Guimond]

Oh boy, looks like my only choice is to split 'em and double down ................ :outtahere:


Carl, I think you might be right on the year being 1971. That was the last year that I raced and Gerry Walin may have been using more than one setup at that time, I remember his trailer sure had a lot of motors and more props than I had ever seen in one trailer with the possible exception of Ted May. If I remember right Gerry was running his Kilo setup at the Divisional and I think he had just upped the kilo record (98mph?) It was the first time that I had seen bounce pipes. Gerry and I had the longest boats of any of the AOH's at the time. Jerry


the 258-lb weight of the KR15 came before it was disassembled for restoration. I weighed it on my digital scale, complete with trim and lift pumps. It is still not back together yet but it is close--powerhead is done, mid, and gearcase too. It does not have the 8-barrel back on it as these can be finicky. Later in the early to mid 1980s the KR15 was run in a class called Formula 100, which allowed the engine but only 4 carb throats--so guys installed the 140 intake and carbs and ran it that way. That's how mine is set up now. Regarding horsepower, I would have to see a KR15 make 200 hp on a dyno to believe it. I don't think they were ever even close. I think the best of the best (those run by Jimbo, Tom Posey, Barry Woods, etc.) may have made around 170 or so, but that's the best there was. Most made in the 150-160 range.


Guys: The factory race engine of the early '70s used 2 Mec power trim units; one for trim (in & out) and one for lift. I actually designed and built a single pump unit as a weight saving that did both, but it was never used. The V-4's put out 180/185 PROPSHAFT hp at the time. That's why when the rotary hit at 265 PROPSHAFT hp they were so dominant.


I didn’t read thru all the replies so this may have been mentioned. Late development on these Super Strangler race engines saw a 15/17 lower become available, they remain a rare item. The lower unit shape also changed shortly after the photo on the first post and got pointy. At one point I building these engines for a few people, we even had a 3.625 bore version with the 8 barrel set up. It was asked why the 6400-6800 listed is low, we used to run them 7200 at the 7HR parker enduro and 7500 -7700 sprint racing.


Freddie is right, it's from the "KC13R" 100 CID from the early 70's. The 14:23 "Club" foot was originally blunt on the front like a fishin' case but the speeds soon exceeded that case shape so later ones had a pointier front. The odd mounting pattern for the foot was a legacy of these gearcases being originally cast up for the X/GT 115 of 1967 which used the "fat 4" shortshaft 15 inch midsection. Later "KR15M" 8 barrel motor had a mount that incorporated a thru transom trim ram. The one on this motor is cast steel and really heavy! A good start for a race motor restoration, all the rest except the special "bubble" back tuner can be modded up.



Nice find. It has been a while since I have seen one but I think it a V-4 Super Strangler (if in Evinrude trim) center and lower unit. I believe the lower unit is a version that was known as a "club foot." It was bigger than the 1:1 that was commonly used and if my memory is correct it was a 14:23 ratio. With it you could run a much bigger diameter prop. You could keep the RPM's much lower (7200 - 7400) and it had great acceleration. Keeping the RPM's down was important when running the engine in long races because it liked to meld pistons if you ran over about 7500 RPM. Top end was less than the 1:1, but on a short course and races with a Lemans start you could get to the first turn first and stay out front. I won some national championships and a bunch of races in Formula 100, Mod 100in the 80's and also ran some endurance races with a 16' Seebold.



Steve is correct, the first OMC V-4 race motors were rated at 116.2 hp. Those were the 89ci X-115 and GT-115. The next OMC motors were 10ci bigger but still carried the "115" names. Either Leek or Strang told me these were 125-130 hp. During the Strangler/Stinger and SuperStrangler/Stinger GP era there were no published hp figures, but a few years later a handicapping scheme was set up in Mod 100 where the various 99ci V-4 and inline 99ci raced together. They dyno'ed several of each motor that were assumed to be typical and not special team motors. The lowest guys on the totem pole were the Stranglers and Stingers at about 165, so they got the lightest weight.

Next inline was the T2 at about 170-175

Then the Super Strangler/Stinger GP at 180-185

And the top dog 99 ci racer was the 190-195ish T2X

Jim Nerstrom may have given us some numbers on the 727 V-6's over on BRF, but I don't recall what the numbers were ... and they weren't production motors like the others mentioned. In fact, many of the motors Rich mentions were not production motors and had a lot of variation from motor to motor.



BigSavage Bluefin[] Thanks Mercman - googled it etc and come up with zilch. You are correct re offshore. I fitted a set to a C Class hains hunter cut down called Sinbin owned by a joker callled Rod Skinner in Hamilton NZ. Sinbin ran an Evinrude Super Strangler with a club foot. Lots of "wise Guys" told us it would not hold up but was a consistant place getter around 77,78 and 79. Good old days

MERCMAN Now there's a good example of a Haines (No plank) with big power. That boat would have been good for 80- 85mph at least. I wouldn't have believed it would have turned out a good combination either, but there you go….As a reminder, the Evinrude Super Strangler was a V4 100ci full factory race motor, reported to churn out around 190 - 200hp. They were primarily built to race on tunnels and compete with the Merc BP's, Twister II's & IIX's of the era.Yep, you're right.. the good old days. Was the Haines a pig to get onto the plane with that motor on it? Maybe that's why the joker had you fit the tabs?

BigSavage Bluefin As you can imagine .... round and round like getting a tunnel boat out of the water but once it was out ... like the wind. Competed in the 1978 Citizen Offshore Power Boat serries from Auckland up through to the Bay of Islands over 5 days .... Now that was a drink!!!

[Greg Guimond]

But wait, there's more ............. :lightning


"Greg, an interesting investigation into the Donzi 16. The gearcase drag is very important. The OMC 1:1 and 14:23, as the larger unit was usually referred to, were both twin pinion. The Mercury Sportmaster is a single pinion gearcase designed for much more horsepower and will be considerable larger than even the 14:23 unit. The diameter of the 1:1 would have been slightly larger than the propshaft, just big enough to install the rear bearing and seal. The 14:23, because it had a reverse gear, was larger to allow the parts to be loaded from the rear. The Super Strangler (KR15M) with 8-barrel carb set up was built with a 1:1 or 15:17, as it was only run on tunnel boats. Doc Jones would have had access to older parts and very likely put a 14:23 on the Donzi as it would have performed best with that gearcase. The 1:1 would have had a hard time carrying the boat. Many GT115's were installed and raced on fiberglass Glastron style boats in the 1967 - 1968 time frame. About the best I can do for now. Good luck in your project. J "

[Greg Guimond]

The 258lb 7200 RPM Super Strangler mighty mouse?

:screwy: I guess it depends. Matty's 1967 #452 is doing 68mph with 205hp but John Benkoczy's 16 only did 55mph with 175hp. Both 20" motors and both the same gearcases. What's up with that?

[mattyboy]

The 258lb 7200 RPM Super Strangler mighty mouse?

:screwy: I guess it depends. Matty's 1967 #452 is doing 68mph with 205hp but John Benkoczy's 16 only did 55mph with 175hp. Both 20" motors and both the same gearcases. What's up with that?


again apples to oranges and all over the page

keep the babies in the crib together same height same bottoms same weight and weight distribution 175-200 hp running 55-60 yet there is the 225 hp merc baby running 75mph with a stock fishing motor at the standard height??? so 25 hp can give a baby a 15 mph speed jump?????someone has to explain that to me

Hull 452 is a unique setup, from pictures i posted has a jack plate and a unique weight distribution like no other 16.
you said 205 hp the owner estimated the HP around 200 based on what the builder told him, it may be closer to 215 or 220 hp

we all know that there are certain setups that perform well above the normal classic speed range. they get there by using a different drive system , raised X, big power, and running surface mods or a combo of each

Waleye's stock 350 mag X18 running mid to high 70's= a raised X and BH drive

Osur's 18 2+3 with a shorty and blown running 90= big power and a shorty

and well Mighty Mouse running 120 = blown SB power an arney drive and rocker plates. a combo of everything above

we all know the 16 runs well with weight out of the azz end Bill's friend with the 4.3, the 4.3 mpi boat i ran with on LK George ran just to about 60 with 220hp supplied by 4.3 mpi weighing in at 665 lbs. How do we think it would run if it had no additional weight for fuel?? everyone picks up a tick or two running on fumes right? Now take hull 452 running 200 ish hp with less than 665lbs in the back including fuel and add a raised X. do we think that 8 mph is possible just like the jump in speed of Waleyes boat over the normal x 18 with a 350 mag???

So the 68mph on hull 452 is something I believe as is the way the 3 boats above run.

again someone is going to have to explain to me how the 225 merc stock fishing baby can hit mid 70's when all the other babies are stuck in the classic speed range??? I can't believe that setup is stock sorry something has to give it that 15 mph boost and that something has to be on the list above.

[Greg Guimond]

Someone is going to have to explain to me how the 225 merc stock fishing motor baby can hit mid 70's when all the other babies are stuck in the classic speed range??? I can't believe that setup is stock sorry something has to give it that 15 mph boost and that something has to be on the list above.

The motor is stock and the actual best top speed was 77mph. It did numerous 75's. I would think the reasons are .............

a. Gearcase Location 50%
b. Driver 20%
c. Steering 10%
d. ?

[mattyboy]

The motor is stock and the actual best top speed was 77mph. It did numerous 75's. I would think the reasons are .............

a. Gearcase Location 50%
b. Driver 20%
c. Steering 10%
d. ?



a) gear case location? so we are saying this is not stock and that by whatever means the gearcase is set to a height that is = to 50% of the 15 mph gain or 7.5 mph over a gear case just bolted on in the stock location.

b) the driver? so the driver of this baby is= to 20% of the 15 mpg gain or 3 mph so this driver put in the other babies would pick up 3 mph is this due to talent weight?

c) steering? is 10% or a 1.5 mph gain so a steering change to the other babies would give them a 1.5 mph bump,?


looking at your pics of John B's baby and the rude on hull 452 if they are the exact motor with the same length shaft there is a lot more under the water on John B's baby

[Greg Guimond]

Just to focus on the gear case for a moment I'm saying that the Merc 225 is a stock motor with a stock lower unit. A lower unit that you can buy off the shelf from the factory today. With wackers, it is very easy to vary where a prop shaft centerline sits below the keel. You can raise the motor up as high as water pressure will allow if you are chasing the top speed number, or bury it down low if you want to pull a tube. The higher you go, the less parasitic drag and drag is 50% or so of the speed problem. This is why I am up to 60% probability that Dr Lou could clock 84mph with the Super Strangler.

I bet if Bill measured his 1967 Ski Sporter 16 with AQ290 that the prop shaft center line is probably 8" below his keel at dead level. Maybe more? That's deep.

[mattyboy]

Just to focus on the gear case for a moment I'm saying that the Merc 225 is a stock motor with a stock lower unit. A lower unit that you can buy off the shelf from the factory today. With wackers, it is very easy to vary where a prop shaft centerline sits below the keel. You can raise the motor up as high as water pressure will allow if you are chasing the top speed number, or bury it down low if you want to pull a tube. The higher you go, the less parasitic drag and drag is 50% or so of the speed problem. This is why I am up to 60% probability that Dr Lou could clock 84mph with the Super Strangler.

I bet if Bill measured his 1967 Ski Sporter 16 with AQ290 that the prop shaft center line is probably 8" below his keel at dead level. Maybe more? That's deep.


Ok so what you are saying is the 75 mph 225 baby has the motor mounted higher very similar to a jack plate so comparing it to a baby like John b's where the ob is just hung on the back is not apples to apples.

[Greg Guimond]

No wacker will be identical in terms of prop shaft to keel distance. It isn't like the car motors.

The strakes aren't in play so the better comparison is probably looking at the 1967 #452 (with jack plate) and the 1975 16 OB Baby (with jack plate) and thinking how one boat can do 68mph while the other does 76mph.

[woobs]

In post # 900 **NOTE** Post numbers changed due to a member deleting a significant part of the discussion (and I can't believe it has gone on this long) your posted quotes on the power output of the Super Strangler are pretty much all nearly under 200 Hp, to way under 200 Hp. There is NO evidence to the contrary.

I think we all agreed early on that much, much more than 200Hp (in a wacker application) was going to be needed to push a Ski Sporter to 84mph. This belief is inclusive of the majical power of strakes in or out of play, the lighter hull levitation theory, the slippery foot supercedes strength statements, the Cg imbalance-in balance controversy, The perfect prop wash acclimation and the dainty (but dedicated, skilled and determined) driver debate....not to mention abandoning common sense, scientific principals and any semblence of a cohesive argument to many of the points discussed.

In the interests of passing the wintertime, I think it's time to concentrate on how this anomolis reading occurred, and find reasons for the erronious 84mph claim, instead of clinging to abstract and circumstantial minutia to purport what has now become an exhaustive rambling of "faith alone".

I'm at 0% that it actually happened.... And a somewhat higher % that Dr. Lou THOUGHT it happened (I don't know him and never met him). After all of this... I'm at a total loss as to how anyone could STILL believe this scenario was possible. It just isn't. ;)

But apparently, YMMV (still).

[Greg Guimond]

The Super Strangler dyno'd at 185 without stacks. That was out of the factory box from OMC Race and Charlie Strang. Now maybe Jack Leek (OMC Race Head Honcho) had a few tweaks up his sleeve but not many. So give Leek 5hp and then give Doc Jones (OMC Race Skunk Works) 10hp for the stacker baseball bat open exhaust. I/O's seem to add a bit of power via open exhaust headers. So call the Super Strangler 200hp at the prop shaft. I'm ok with this number as Alan Stoker has raced them, and re-built them. Alan is probably the foremost authority on OMC wackers today and also an accomplished racer himself. He is kinda the Jack Leek/Doc Jones type.

So 200hp propshaft and 7200rpm for a 1975 OMC Super Strangler KR15 8 carb race motor pushing 1600lbs of round bottom 1965 Donzi 16 to 84mph?

Someone has to tell me how a Merc 225 is pushing a heavier OB Baby to a documented 76mph and 8mph faster is not possible? 8mph is no sneeze but I'm at 60% possible and climbing. Matty getting the prop size and make from the owner of #452 will also be interesting.

How big a prop does #452 have to spin to get 68mph? How big a prop does the 225 Merc have to spin to get 76mph?

[woobs]

Or, you could say....

In my 2-stroke days I've seen as many motors NOT benefit from pipes (and actually produce less power) without a lot of testing & tuning. This always involves a dyno. Celebrity Hp at 5Hp is just a gift that may be the why we're at 185 Hp up from 175 Hp. So why round up the rounding? 185Hp dyno'd = a fact we have. Why choose to embellish some facts while discounting others?

I see 40 real Hp short of a 225Hp boat, that was still 10 mph slower than where you need to be ...and it was running at the absolute limit.

So, if 10Hp=2mph (and generously assuming no dimishing returns) you are 90Hp short minimum ... and still need to make the planets align for every other factor outside the power issue. 185Hp + 90Hp = 275Hp (min req)

At these numbers (which are no more of a stretch than yours are) you need to beat 275Hp or equivilant with power savings to do 84mph. With this you are saying this SS/Ski Sporter set up pushed the equivilant of 49% more power/less drag than the known starting point of 185Hp. Reality would say you need to be closer to 300Hp to do this but you are so far out I don't need to even go there.

If I could post lower than 0% I'd be there. The more real facts that come out the more I'm sure it didn't/couldn't happen.

What is the gear ratio of the Super Strangler?

[Greg Guimond]

Embelishment? Come on woobs with your (2 stroke) experience of course there would have been a lot of testing and tuning, Jack Leek ran OMC Racing for years. He wasn't a celebrity as you put it, he was one of the most gifted race motor guys in the world. Not the US, the world. That is certainly worth a few ponies to most folks I would think. The Super Strangler only kicked the pants off Mercury during those years. In fact, Walin won the Parker 9 hour Enduro driving for OMC.

It's really down to a 205hp Johnson pushing a 16 to 68mph, a 225hp Merc pushing a heavier 16 to 76mph and a 200hp Super Strangler pushing one to 84mph. I'm still poking around on that to see if/how that 8mph could be have a shot. Ghost will opine I'm sure :embarasse

[woobs]

Or, you could say....

In my 2-stroke days I've seen as many motors NOT benefit from pipes (and actually produce less power) without a lot of testing & tuning. This always involves a dyno. Celebrity Hp at 5Hp is just a gift that may be the why we're at 185 Hp up from 175 Hp. So why round up the rounding? 185Hp dyno'd = a fact we have. Why choose to embellish some facts while discounting others?

I see 40 real Hp short of a 225Hp boat, that was still 10 mph slower than where you need to be ...and it was running at the absolute limit.

So, if 10Hp=2mph (and generously assuming no dimishing returns) you are 90Hp short minimum ... and still need to make the planets align for every other factor outside the power issue. 185Hp + 90Hp = 275Hp (min req)

At these numbers (which are no more of a stretch than yours are) you need to beat 275Hp or equivilant with power savings to do 84mph. With this you are saying this SS/Ski Sporter set up pushed the equivilant of 49% more power/less drag than the known starting point of 185Hp. Reality would say you need to be closer to 300Hp to do this but you are so far out I don't need to even go there.

If I could post lower than 0% I'd be there. The more real facts that come out the more I'm sure it didn't/couldn't happen.

What is the gear ratio of the Super Strangler?

So if we work the problem the other way...

A 225Hp 16 does 74mph and 10Hp = 2 mph.
The Super Strangler is 185Hp or -40Hp difference.
40Hp = 8mph.
So an equivelent comparison would be the Super Strangler at 74mph - 8mph or 66 Mph. Just what one would expect of a racy o/b from the 70's on a 16 Ski Sporter.

66mph is still pretty quick for a Ski Sporter. Now imagine that the high strung race engine that was once pampered every race weekend is now an old classic boathouse trophy that gets used recreationally and rebuilt/tuned...almost never. Probably a little tired. Let's assume that Dr. Lou is a regular guy and not a top OMC engineer or an ACE driver. There is some boating "stuff" stowed in the boat. Regular gas. some chop on the water, not the perfect prop selection. a Ski Sporter hull that is well known to not handle well in the high 50 mph range, it's a regular day and the planets are not aligned.... and voila you're easily at 52 mph with a wild ride and your hair on fire.

Now imagine the above with your GPS unknowingly set to KM instead of MPH and you see the number 84!
Oh, btw...84kph = 52.2mph.

My grade 7 math teacher used to tell us when we were solving problems: "When you have an answer, ask yourself if it is reasonable. If it's not, you have mad a mistake".

I think a GPS switch may be the reasonable answer here.

[woobs]

Jack Leek ran OMC Racing for years. He wasn't a celebrity as you put it, he was one of the most gifted race motor guys in the world. Not the US, the world. That is certainly worth a few ponies to most folks I would think.

If he were any good (and aparently he was) and he was a company man, don't you think he would have released those ponies BEFORE they shipped them out to the race teams? Maybe he did his R&D at the OMC R&D facilities and just looked for feedback from the racers to aid in future designs? It does not help a company when one team gets the "real" motor and everyone else has the standard race equipment. he would have wanted all the OMCs to beat Merc... not just one.

I'm saying maybe Leek is the reason the pipes appeared and the SS in question had 185Hp and not 175Hp like everyone else. So we already counted him "in" for 10Hp. And you want to increase that 50% because of his title. That's celebrity. (so is the moniker "most gifted race motor guys in the world")

A 205Hp Johnson pushing a Ski Sporter to 68.... Hmmmm, lets see.
That's 20Hp more than a Super Strangler.
10Hp = 2mph. 20Hp = 4mph.
Super Strangler at 66mph, Johnson at 68mph = difference of 2mph.
I'd say that was right in the ballpark with a 2mph margin in favour of the Super Strangler for it's slippery foot.
Nothing unbelieveable here.

[Ed Donnelly]

Sorry just can't buy any southern gentleman setting his GPS up for KPH

Anyone who has done 80 in a 16 knows when he is doing 50
I am in the 100% Lou did it

But then again I believe Mary was a virgin when she had Jesus
as do another 1.2 billion people. Ed

[woobs]

Awwww, c'mon Ed. I had it all figured out. :)

GPS units were new tech in 95-96... maybe it was at factory settings :bighug:

As for the faith end of it... your numbers may not carry the day as I'd hate to add up all the Jews, Muslims, Buddists, Hindus etc...in the world that don't quite see that your way.......

[Ed Donnelly]

Awwww, c'mon Ed. I had it all figured out. :)

GPS units were new tech in 95-96... maybe it was at factory settings :bighug:

As for the faith end of it... your numbers may not carry the day as I'd hate to add up all the Jews, Muslims, Buddists, Hindus etc...in the world that don't quite see that your way.......

Yah but none of them will be able to argue the point with me in heaven
cuss they don't know where heaven is

GUYS Just trying to lighten up this thread a little besides
I filmed the Dr. Benz run and have it on my 8 track....Ed

[Greg Guimond]

Sorry just can't buy any southern gentleman setting his GPS up for KPH

Anyone who has done 80 in a 16 knows when he is doing 50
I am in the 100% Lou did it

But then again I believe Mary was a virgin when she had Jesus
as do another 1.2 billion people. Ed


How about the Virgin Mary and the 16 ...........now that's a vision! She was a flyweight!!

[Greg Guimond]

So if we work the problem the other way...

A 225Hp 16 does 74mph and 10Hp = 2 mph.

The Mercury 225 pushed the heavier 1975 16 OB Baby to 76mph, not 74 so we would have to start with that. Where is the 10hp = 2mph coming from?

[mattyboy]

some items I would like to point out

Greg
in one of the links you posted from way back when Big Grizzly weighed his 66 16 and it was heavier than advertised and was a stock 289 i/o so I am not sure a baby is heavier

in the video of Walin setting the record the pit chief stated they tweaked the mixture to ring the HP out of the motor, great strategy for a one time two pass record run but I would imagine not the best way to run a non raceboat seems the motor wouldn't last to long. Again all the boats I mentioned are capable of their speed on a daily basis not a one time thing.

looking at the pics of the baby well the lip is MUCH lower than the lip on 452, the last pic of the baby you posted with the johnson 200 looks to have a stern jack. on all of the johnrude boats you posted the transition of the motor cowling to the shaft housing look to be right at the well lip .

on 452 the lip is a few inches higher and the jack takes it much higher from there, the transition from the motor cowl to the shaft looks to be even with the deck hull lip.

[Greg Guimond]

Couple of questions Matty ........


some items I would like to point out

Greg
in one of the links you posted from way back when Big Grizzly weighed his 66 16 and it was heavier than advertised and was a stock 289 i/o so I am not sure a baby is heavier

That is a good point. I have to look back but I remember that Grizz was very precise. Did his comment include the trailer's weight do you know?

in the video of Walin setting the record the pit chief stated they tweaked the mixture to ring the HP out of the motor, great strategy for a one time two pass record run but I would imagine not the best way to run a non raceboat seems the motor wouldn't last to long. Again all the boats I mentioned are capable of their speed on a daily basis not a one time thing.

What video are you referencing? I think you are talking about the Havasu run for the world record?

[mattyboy]

yes the havasu run. my point when race guys tweak they are not concerned if the motor will run next weekend they just want it to cross the line first today.

pretty sure Grizz was talking just boat

[Greg Guimond]

That video was the 1966 Havasu run with a very purpose built motor designed for Gerry to set the World Record. Years later, the Super Strangler was a different animal. It had a very long run of dominance. While it was a full blown race motor, there were many of them made and they were run in some pretty grueling races like the Parker 9 hour. They were considered to be very stout and reliable by race standards.

I'm checking on the Grizz weight. I know that we are using 1600lbs for the 1965 16.

[Greg Guimond]

Here is one of Grizz's posts. I think there was also one other that I am looking for.


Let me answer a few questions. Our 1966 16 with the H&M 289 from the factory with maybe 6 gal of fuel weighed 2775 pounds on a Toledo scale back in 1967.

Here is the other post .........


Our 1966 16 weighed in at 2476 no gas but engine and battery and it was a 289 and we bough it new

[Greg Guimond]

Here is the rest of my thoughts .....


some items I would like to point out

looking at the pics of the baby well the lip is MUCH lower than the lip on 452,

Good observation and I agree. Are you saying for example that the splashwell lip on 1967 #452 is perhaps 5" below the rub rail while the 16 OB Baby's are 10" below?

the last pic of the baby you posted with the johnson 200 looks to have a stern jack. on all of the johnrude boats you posted the transition of the motor cowling to the shaft housing look to be right at the well lip.

Yes, the 16 OB Baby with the Johnson 200 picture has the outboard mounted to a jackplate

on 452 the lip is a few inches higher and the jack takes it much higher from there, the transition from the motor cowl to the shaft looks to be even with the deck hull lip.

What are you suggesting?

[Greg Guimond]

Cobbling together the weights. I still have a c note that when woobs weighs his naked 16 Ski Sporter it will be 900lbs, not 1,000 :biggrin.:


as it seems we are back on weight lets look at where the weights would be. A 1966 16 ski sporter with the standard 110 hp volvo AQ200 drive weighs 1500 lbs approx as stated by the 1966 literature. according to volvo penta documentation the 110 volvo with aq200 complete weighs 495lbs, the tank with 20 gallons would be 180lbs using greg's formula


Let me answer a few questions. Our 1966 16 with the H&M 289 from the factory with maybe 6 gal of fuel weighed 2775 pounds on a Toledo scale back in 1967.


Our 1966 16 weighed in at 2476 no gas but engine and battery and it was a 289 and we bough it new


And here are more 16 OB Baby weights from electronic scales .......


We were able to put the hull and the deck on an electronic 2000lb scale. The hull weighed in at 698lbs. Then we did the reconfigured deck and it came in at 409lbs, more then I would have thought.
Total weight unrigged and without gas tank is 1107lbs.


Maybe this is of some use, my 16 OB deck weight was 343lbs

[Greg Guimond]

Sooooooo .......

1. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 do 55mph? ................................yes
2. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 skinny "E-drive" do 61mph? .........yes
3. Can the 1967 Ski Sporter 16 #452 with a 1998 Evinrude V6 (210hp) O/B do 68mph? ......yes
4. Can a 16 OB Baby with a 2004 Mercury V6 (225hp) O/B do 76mph? ..............................yes



1965 Ski Sporter boat weight "naked" with empty gas tank and brightwork - 1,000lbs (I still think it is 900lbs) ......................................check
1965 Ski Sporter total weight with 25 gallon tank full, Super Strangler O/B, a driver, and all the bits & pieces - 1,600lbs (per Matty) ........check
1965 Ski Sporter 55ers as compared to 1975 16 OB Baby 21 inner strakes at 65mph and above - no real effect .....................................check
1975 race propeller technology as compared to 2014 consumer props - about equivalent .................................................. ..................check
1975 OMC Super Strangler horsepower (200 at the prop shaft) .................................................. .................................................. ..check
1996 Garmin GPS technology in Miami and GPS reading quality in general .................................................. ......................................check

Direct comparison of 1967 #452 doing 68mph with 210hp to 16 OB Baby doing 76mph with 225hp .................................................. ...?????
Direct comparison of 1967 #452 doing 68mph with 1965 16 doing 84mph .................................................. .....................................?????

Possible 84mph from Dr. Lou in 1996 in saltwater ..................... hmmmmmm

[Ghost]

1965 Ski Sporter 55ers as compared to 1975 16 OB Baby 21 inner strakes at 65mph and above - no real effect .....................................check
1975 race propeller technology as compared to 2014 consumer props - about equivalent .................................................. ..................check
1975 OMC Super Strangler horsepower (200 at the prop shaft) .................................................. .................................................. ..check


1. Huh?!
2. Not check, but maybe.
3. Almost certainly not.

[Greg Guimond]

4. Can a 16 OB Baby with a 2004 Mercury V6 (225hp) O/B do 76mph? ..............................

whose boat is/was this? 76mph with a stock 225 upper and lower?? Opti or EFI 225? and you went 79mph with an actual 245hp and sleeker lower?

i'm still in Missouri on the 68 and 84 claims of those 2 boats....a 205 boat goes 68 and then a boat with only 20hp more, a 225 (205/68 vs 225/76 vs 245/79) goes 76, then another 20hp only goes 79?
as more days go on, it's getting crowded out here :umbrella: :D

BUIZILLA, it was a bone stock 2004 Mercury 225 "EFI" with a stock TM factory lower unit and hydraulic front mount steering mated to a 1975 16 OB Baby with 21s. Exact GPS was 76.2mph one way. Run the #s :yes:

[Greg Guimond]

Doc of high MPH speeds? Here is the note that claims the 84mph for "1965 16OB#1"




From: Dr. Lou Benz
Sent: Wednesday, July 03, 2013 3:02 PM
To: Guimond, Greg
Subject: RE: 1965 Donzi 16 - 1975 Evinrude Super Strangler 135

84 mph as indicated by a Garmin GPS on a calm day in the bay of Miami. I was racing against an Allison that was manned By Osiris Perez AKA “Chief”. Chief worked as a mechanic for River Marine in Miami and bragged he had a fast boat. He got me off the start but I quickly overtook him when my boat reached optimum angle. I wanted to make sure he did not challenge me again so I let my ego dictate the amount of risk involved and foolishly reached WOT for what seemed an eternity but in fact was about a minute. I would repeat the run with him aboard an hour or so later to prove my speed. I have never again committed such a stupid act. Chief never challenged me again but instead he bragged about my boat to others. I have had faster boats since but not that small. Keep in mind this was not a very heavy hull as evidenced by the stress cracks that I had to repair multiple times on the freeboard and deck.

[Carbo]

84 With 2 people in it? I put my boots on pages ago. I think I need waders....It's getting deep in here.:cool:

[Greg Guimond]

apparently, I missed something earlier... so, it easily ran 84 with 2 aboard now..... add another 200# like it's nothing, and rip off an 84 again.... the next CRA event is this coming weekend, he'd be the talk of the universe if he showed up with it ;)

I don't see the word easily and who said Perez was 200lbs? I thought that the glass guys who worked for Donzi were flyweights? Maybe Osiris was related :) What if he weighed 135 like Gerry Walin? Or, you could look at your boat that did not deviate 1mph when you removed your buddy as I remember, correct?

But back to a prior point, have you come to grips with the 225 Mercury running 76mph yet? We need to put that one to bed once and all for the Missouri crew, it is getting lonely out there from what I can tell :rolleyes:

[Greg Guimond]

84 With 2 people in it? I put my boots on pages ago. I think I need waders....It's getting deep in here.:cool:

Carbo's in for a cameo appearance! Ok, what are you running for wacker power these days and what is the GPS speed? I can't remember if you have the TRP lower and a 200 or not.

[Greg Guimond]

I don't believe the 84 with one, much less 2..... and no, i'm not believing the 76.2 with the bone stock 225 either, hell no

Said in jest but I think you need to get rid of that high drag TRP. It's slowin ya down cause you can't surface it :biggrin:. Just kidding, I know you love it for the handling and that makes for a nice easy ride.

[Ghost]

I don't see the word easily and who said Perez was 200lbs? I thought that the glass guys who worked for Donzi were flyweights? Maybe Osiris was related :) What if he weighed 135 like Gerry Walin? Or, you could look at your boat that did not deviate 1mph when you removed your buddy as I remember, correct?

But back to a prior point, have you come to grips with the 225 Mercury running 76mph yet? We need to put that one to bed once and all for the Missouri crew, it is getting lonely out there from what I can tell :rolleyes:

You're right that the word isn't there but I think he meant that it was implicit: "oh, 84, sure, no problem, hop in and we'll go do it again."

As as for the weight, I think you'll find that even 135 would be very significant. (Consider by you own math how much speed increase you'd predict from TRIMMING 135 lbs.). And btw, speed sensitivity to weight changes increases with speed. 61 with one person or two is different from 84. I had a 22 Cobalt with a big block--it'd do 54.5 with one person and 54.0 with 7 on board.

[Greg Guimond]

Ghost curious, do you think that the 225 Merc did 76.2mph?

[Carbo]

Cameo......I'm always lurking around. :smile:

My boat runs great. Stock 150 OX66 with TRP lower...TRP cowling also.

I have only logged 10 hours running it. Max gps speed is 84...eh I mean 57ish..ha ha, It is a blast to drive but over 52 it starts walking side to side. Even when its fairly flat out You can drive through it but I make sure the lanyard is securely attached. I'm trying to get more seat time and experience. I wonder if the 12" setback is too much.

I was checking parts and looks like I can get 200hp with OX66 200 heads and ECU......I'm keeping my eyes open. Dont know if the extra power will be useless without going solid motor mounts and some other tricks,,,but I'm willing to try!

[Greg Guimond]

Cameo......I'm always lurking around. :smile:

My boat runs great. Stock 150 OX66 with TRP lower...TRP cowling also.

I have only logged 10 hours running it. Max gps speed is 84...eh I mean 57ish..ha ha, It is a blast to drive but over 52 it starts walking side to side. Even when its fairly flat out You can drive through it but I make sure the lanyard is securely attached. I'm trying to get more seat time and experience. I wonder if the 12" setback is too much.

I was checking parts and looks like I can get 200hp with OX66 200 heads and ECU......I'm keeping my eyes open. Dont know if the extra power will be useless without going solid motor mounts and some other tricks,,,but I'm willing to try!

I have run 12" setback. With a TRP I doubt it benefits you as much as you can't get the drive high enough. You should also check the bolts and bushings on the Paralift unit. I have always swapped mine out for new bushings and Grade 8's. Any movement in that unit will transmit quickly especially if you don't have solid motor mounts.

[Ghost]

Ghost curious, do you think that the 225 Merc did 76.2mph?

Don't know.

In your mental math, how much speed increase do you grant for dumping 135 lbs of weight?

[Greg Guimond]

Come on, you don't know about 76.2 with 225hp? Sure you do. BUIZILLA came clean with the big NO. I'm saying YES, the guy did it. Your the tie breaker :flag-navy

[Ghost]

How much wot speed increase would you expect from a 135 lb weight reduction?

[woobs]

I was under the impression that the 76.2 was documented on you tube (or posted to some other media). If so, it's a given that it happened...but, it's not a given that it's stock.

What is the gear ratio on the Super Strangler?

[Greg Guimond]

Someone's going to have to explain to me how the 225 merc stock fishing baby can hit mid 70's when all the other babies are stuck in the classic speed range? I can't believe that setup is stock something has to give it that 15 mph boost


Sorry, anyone who has done 80 in a 16 knows when he is doing 50, Ed


I don't believe the 84 with one, much less 2..... and no, i'm not believing the 76.2 with the bone stock 225 either, hell no


I don't know. Still.


I was under the impression that the 76.2 was documented on you tube (or posted to some other media). If so, it's a given that it happened...but, it's not a given that it's stock.

Here is the post boys from the gentleman that clocked 76.2mph with the 2004 Mercury 225. The motor and lower unit were stock, I helped him with the set-up a bit at the time and I believe his speed. From my experience with 16's it sounds reasonable. Someone can run the #s though to be sure. Also, this was his second 16 OB Baby so he was not a newb to the round bottom hull. Was he Gerry Walin's caliber? No, but he is probably akin to Dr. Lou's level of skill. I chose to use the lower 76.2mph because I also believe that Ed did 100mph and I don't want to be tarred and feathered, it is not a fashionable look in LaLa Land :lookaroun:


I run today with 1/4 of gas at a higher trim than the last run. Run 77.7 @5750 rpms (overspeed alarm sound) Have a slip of .083% and run the other way 76.2. Your coment sound logical but iff I run faster with more trim , I believe I need to raise the engine a little more in the jackplate to get more prop out of the water without loose the grip. I try to run one time at maximun height but dont work. I will try a 1/2 inch at a time. even with a zero slip I Cant reach the 80 mark with these prop. I considere a Tempest plus 28 Lab.

The point is it is not all about horsepower with a wacker. Set up plays a crucial role and driver skill counts for something. I am now at 70% that Dr. Lou clocked 84 on a fine Miami day in 1996 :umbrella:

[woobs]

Again, what is the gear ratio on the Super Strangler?

BTW, I don't doubt for a nano second that Ed passed the century mark with his 16.
Modified hull, about a Gazillion horsepower and piloted by a steely eyed Canadian boy....

[duckhunter]

Here is the post boys from the gentleman that clocked 76.2mph with the 2004 Mercury 225. The motor and lower unit were stock, I helped him with the set-up a bit at the time and I believe his speed. From my experience with 16's it sounds reasonable.

The point is it is not all about horsepower with a wacker. Set up plays a crucial role and driver skill counts for something. I am now at 70% that Dr. Lou clocked 84 on a fine Miami day in 1996 :umbrella:

Running 76 with a modern 225 and perfect setup sounds very plausible. I don't see how losing 20+ horsepower with the strangler equates to gaining 8mph, and I don't care if that's with a slick lower or a flux capacitor. It just appears somewhat counter-intuitive. What the hell do I know though, I've been killing brain cells in Missouri for almost a month!

I'm sticking with the 300 black motor, great setup, and a great wheel man. Also - did you account for the size of the nads it takes to run that fast in a Donzi 16? Seems like that might add some drag to the equation.

[woobs]

From what I can find the Super Strangler had two available gear ratios.
A sprint set up at 1:1 and a race set up at 1.65:1. This is just math and not real life but, it gives an idea of what kind of wheel you'd have to swing to attain 84mph at 7,200 and 10% slip. We're probably NOT looking at the sprint ratios but I included them anyways.




PITCH

x

RPM




Theor



Actual



RATIO

x

1056




Speed


slip


Speed





23

x

7,200

=

165,600.00

=

95.0


0.9


85.5



1.65

x

1,056


1,742.40

















14

x

7,200

=

100,800.00

=

95.5


0.9


85.9



1

x

1,056


1,056.00

[Greg Guimond]

Attention shoppers. Kenworths will be available for those seeking to leave Missouri. First come, first served though :rofl:

[Greg Guimond]

From what I can find the Super Strangler had two available gear ratios.
A sprint set up at 1:1 and a race set up at 1.65:1. This is just math and not real life but, it gives an idea of what kind of wheel you'd have to swing to attain 84mph at 7,200 and 10% slip.

Don't jump the gun just yet. I'm only at 70%. Run the same math for the 2004 Mercury 225 fishing motor pushing the 1975 16 OB Baby to 76.2 and see what you come up with?

[woobs]

Attention shoppers. Kenworths will be available for those seeking to leave Missouri. First come, first served though :rofl:

Au contraire....I think a unicycle and a side car will cover the believers of this myth.
Not even the Wacker crazys at Scream & Fly believe that this happened / could happen!

[woobs]

Run the same math for the 2004 Mercury 225 fishing motor to 76.2

What's the gear ratio and rpm @ WOT of the 225?

[Greg Guimond]

1.75 and 5700

[woobs]

Here you go..... 1.75:1 at 5,750 rpms and 10% slip

Pitch x RPM
Ratio x 1,056.................................... speed slip actual speed



28

x

5,750

=

161,000.00

=

87.1


0.9


78.4



1.75

x

1,056


1,848.00

[duckhunter]

Attention shoppers. Kenworths will be available for those seeking to leave Missouri. First come, first served though :rofl:


Not ready to leave just yet. However, we're running dangerously low on rum and I just put on my last pair of clean drawers. If you could load up that KW with a resupply package before you send it out that would be great.

[Ghost]

Greg, still wondering how much wot speed increase you would expect from a 135 lb weight reduction. You were looking into all sorts of nuance about weight (amounts much smaller)--what do you think a weight savings like this would yield?

[Greg Guimond]

it's damn cold out here in Missouri. is that 8.3%? if that STOCK 225 ran 76.2 Greg, your Promax 225 at 245hp is a Supreme Dog to *only* run 79mph
Ah yes ..... a convert. I agree, it must be getting cold for you boys in Missouri and I also agree that my 16 is a Supreme Dog. :odie: But remember, I can't drive it worth a chit, I basically just go out and try to break it!

[Greg Guimond]

Sooooooo .......

1. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 do 55mph? ................................yes
2. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 skinny "E-drive" do 61mph? .........yes
3. Can the 1967 Ski Sporter 16 #452 with a 1998 Evinrude V6 (210hp) O/B do 68mph? ......yes but still waiting on Matty to get specific prop data and gas tank size from owner of 1967 #452
4. Can a 16 OB Baby with a 2004 Mercury V6 (225hp) O/B do 76.2mph? ...........................yes

[duckhunter]

I don't think anyone hanging out in the "show me" state is ready to convert just yet. I thought the question wasn't "Can a 16OB go 84mph with a whacker?", but rather, "Could (or did) a 16OB go 84mph with a +/- 200hp whacker and a couple of dudes on board?" Or one dude and a goat, or a midget, or whatever.

We gotta nail down the basic premise that everyone is arguing, or I might as well hang out here in MO until Inferno shows up for the shootout (in yet another storied Donzi, but one with recent pictures and a big honking Whipple setup).

Winter bench racing is kind of fun. Can we do a Whaler thread next? :kingme:

[Greg Guimond]

1. 1965 Ski Sporter 55ers as compared to 1975 16 OB Baby 21 inner strakes at 65mph and above - no real effect .............................
2. 1975 race propeller technology as compared to 2014 consumer props - about equivalent ..................................................
3. 1975 OMC Super Strangler horsepower (200 at the prop shaft) ..................................................

1. Huh?!
2. Not check, but maybe.
3. Almost certainly not!


Now that a stake has been driven through the heart of 76.2mph from a 225, I'll need the next convert to please step up to the Kenworth for boarding.

Ghost, let’s throw out the props as “neutral” and focus on the Super Strangler motor for now as I know that BUIZILLA was/is questioning how the other motor with only 225 propshaft horsepower can clock 76.2 mph. Below are two different sources saying a stock Super Strangler from OMC Race Division dyno’d at 185hp to any privateer race team willing to write the check. One of the sources below was a factory race division employee at the time working for Jack Leek and who left OMC in June 1976, the last year of production for the Super Strangler V4 Race. Woobs made a comment earlier to the effect that OMC would have wanted to get the best horsepower number “out there” and published. That could not be further from the truth in the factory race wars between OMC and Mercury back then as told by the guys that were there in person. Actually, even today race teams would go stealth if/as rules allowed. So we have 6 model years (’71-’76) of Super Stranglers that dyno’d 185hp to the open market with tweeks year to year. Don’t you think that a factory team motor might have had just a little more juice to be able to compete and beat the Merc T2X which at the end was formidable? And then add the open stacker exhaust that ONLY team race motors had. Those could not be bought by a privateer. Gerry Walin’s boat had the stacks as Dr. Lou vividly describes. Things are on race motors for a reason.

I think that 200 ponies is reasonable for a late model race build. And duckie, you are spot on ........... Can a 200hp Super Strangler push a 1965 Donzi 16 weighing 1600lbs to 84mph? I'm up to 70%

How about; Did you hear about the Super Strangler …….. Everybody got to go! :band:



Guys: The factory race engine of the early '70s used 2 power trim units; one for trim (in & out) and one for lift. I actually designed and built a single pump unit as a weight saver that did both, but it was never used. The SS V-4's put out 180/185 PROPSHAFT hp at the time. That's why when the rotary hit at 265 PROPSHAFT hp they were so dominant.

I didn't read thru all the replies so this may have been mentioned. Late development on these Super Strangler race engines saw a 15/17 lower become available. At one point I was building these engines for a few people, and there was a 3.625 bore version with the 8 barrel set up. We used to run them 7200 at the 7HR Parker Enduro and 7500 -7700 sprint racing.


Correct, during the Strangler/Stinger and SuperStrangler/Stinger GP era there were no published hp figures, but a few years later a handicapping scheme was set up in Mod 100 where the various 99ci V-4 and inline Mercury 99ci raced together. They dyno'ed several of each motor that were assumed to be typical and not special team motors. The lowest guys on the totem pole were the Stranglers and Stingers at about 165, so they got the lightest weight. Next in line was the T2 at about 170-175. Then the Super Strangler/Stinger GP 8 pumper at 180-185hp. And the top dog 99 ci was the 190-195ish T2X

In fact, many of the motors Rich mentions were not production motors and had a lot of variation from motor to motor.

I have had a 1976 Super Strangler just like the one Johnny Sanders won the 1976 world outboard championship in since 1978. The flywheel has a spring loaded rocker in it so in rough waters the crankshaft won't break off and (4) 2bbl carbs sitting right over the transfer ports. It has the larger, heavier gearcase on it with .7 gearing, which holds the engine/boat in the water better in rougher windier conditions. The same one Johnson spoke of in the promo video during the '76 boat shows, but is not as fast as the smaller gearcase with 1-1 gearing. I remember Jimbo coming to a race on the Fox River in 1972 pulling his Molinari with a Blue El Camino that Goat owned back when he lived in Wonder Lake Illinois. The motor is not for sale, my dad got it for me 4 months before he died in '78. I've had it on a multitude of boats and have not decided what the next toy will be.

[Greg Guimond]

Very interesting Dr. Lou speed calculation woobs, very, very interesting indeed ...............



From what I can find the Super Strangler had two available gear ratios. A sprint set up at 1:1 and a race set up at 1.65:1. This is just math and not real life but, it gives an idea of what kind of wheel you'd have to swing to attain 84mph at 7,200 and 10% slip. We're probably NOT looking at the sprint ratios but I included them anyways.




PITCH
x
RPM



Theor


Actual


RATIO
x
1056



Speed

slip

Speed




23
x
7,200
=
165,600.00
=
95.0

0.9

85.5


1.65
x
1,056

1,742.40
















14
x
7,200
=
100,800.00
=
95.5

0.9

85.9


1
x
1,056

1,056.00

[Greg Guimond]

But wait, there's still more ............. :lightning

Remember that Dr. Lou said he was working for Bertram at the time and purchased "OB#1" directly from Doc Jones in 1976. Gerry Walin had passed away in 1976 and CW "Doc" Jones was helping clean up the loose ends after the tragedy. I was lucky to get a note a couple of weeks ago from the gentleman below to further shed light on the "old" lower unit as it might compare to my "modern technology" Mercury Sportmaster 1.87 .......


"Greg, an interesting investigation into the Donzi 16. The gearcase drag is very important. The OMC 1:1 and 14:23, as the larger unit was usually referred to, were both twin pinion. The Mercury Sportmaster is a single pinion gearcase designed for much more horsepower and will be considerable larger than even the 14:23 unit. The diameter of the 1:1 would have been slightly larger than the propshaft, just big enough to install the rear bearing and seal. The 14:23, because it had a reverse gear, was larger to allow the parts to be loaded from the rear. The Super Strangler (KR15M) with 8-barrel carb set up was built with a 1:1 or 15:17, as it was only run on tunnel boats. Doc Jones would have had access to older parts and very likely put a 14:23 on the Donzi as it would have performed best with that gearcase. The 1:1 would have had a hard time carrying the boat. Many GT115's were installed and raced on fiberglass Glastron style boats in the 1967 - 1968 time frame. About the best I can do for now. Good luck in your project. J "

Very nice man with a ton of details on one of the most important parts to my 84mph equation.

[woobs]

Very interesting Dr. Lou speed calculation woobs, very, very interesting indeed ...............

Don't get too excited. it is not a speed calculation. It is just an equasion that solves for unknowns when other info is plugged in. In this case a 23" pitch prop is required to satisfy our other parameters. It does not tell you the diameter of the prop, surface area etc...

It also in no way qualifies what power is required to spin a 23" pitch prop 7,200 rpm achieving 85mph.

[Greg Guimond]

You guys are still all wound up about the car ponies. When one is in the LaLa Land desert, seeing double doubters from Missouri dwindling ...... each scrap of theory is like a gallon of cool water to a parched traveler :eek!:

[Greg Guimond]

Running 76 with a modern 225 and perfect setup sounds very plausible. I don't see how losing 20+ horsepower with the strangler equates to gaining 8mph, and I don't care if that's with a slick lower or a flux capacitor. It just appears somewhat counter-intuitive. What the hell do I know though, I've been killing brain cells in Missouri for almost a month! I'm sticking with the 300 black motor.

Watch out now, that institutional thinking will get ya. Remember we are talking about the Super Strangler, not the earlier Strangler of 1969-1970. Sure it's counter intuitive, until you say hello to my little friend ......... parasitic drag. I'm sure Ghost will opine on that shortly. Before I get to that though, Jack Leek decided to drop by. He heard you are calling for a Merc 300X to get to 84mph instead of his OMC mighty mouse. Jack hates Mercury duckie, here is a clip of the 1969 OMC Strangler, the little brother to the later Super Strangler 8 Pumpers.

Them hamsters iz singin and Bobs ears iz ringin ..........


http://www.youtube.com/watch?v=zMPjWE_ejRk#t=10

[woobs]

Okay, now that's totally weird..........
Every time I read your posts I imagine them in the voice of Dr. Sheldon Cooper.... Lol.:eek:

[duckhunter]

If a 1970s tech 99cid +/- 200hp whacker will spin 7400rpm with a 23P prop on a 16' 1600# deep-v hull I will eat my shorts and/or buy you a case of beer.

I've got a lot of love for the OMC stuff myself. My first "solo" was a 14' tin Lund with a 25 Johnson Sea Horse at about age 7, or whenever I was strong enough to start it myself. But, the X is a bad dude.

Tell you what, you rig one with the strangler AND one with the black motor and we'll see what happens...

[Greg Guimond]

and no, i'm not believing the 76.2 with the bone stock 225 either, hell no


word.... The End

Word..... 76.2 in "the bag" and going up :)

[Greg Guimond]

Tell you what, you rig one with the strangler AND one with the black motor and we'll see what happens...

I'd need two motors ;)

[duckhunter]

I'd need two motors ;)

TWO cases of beer if you do that! Definitely a top 10 Darwin Awards contender, but what a hoot that would be!

At this point I'm looking at this whole thing as a bit of a "Mythbusters" episode. You have done a tremendous amount of research, and in my mind at least it mostly points to the virtual impossibility of running 84 on 200hp. Myth busted.

So, in the spirit of Mythbusters, take 2 is to figure out what it WOULD take to get the 16OB to 84. That's where the X motor comes in.

As far as the KW coming to Missouri goes, I'll take the Smokey & the Bandit old-school version. But not just yet.

[Greg Guimond]

Sorry BUIZILLA .............


Greg, keep it real, and leave your PM out of the suppostion pic's

Absolutely agree. My boat is for picture yuks only as I'm sure you know and has no bearing on this conversation. The Mule is clearly slow based on the discovery in this thread. I now have to upgrade lol

the supposed 76.2 was with a STOCK 225, not your PM in the pic's

It's not supposed, as I told you 76.2 (77.7 the other way) was done with a stock 2004 Mercury 225 20" and a stock TM 1.75 Lower Unit

never did find out what prop and height it was run at

Prop for 76.2 was a non-labbed Tempest Plus

never did find out what prop and height Big Lou was using

Prop for Dr. Lou has already been neutralized as it was a race prop versus a consumer prop. He told me he used a three blade most of the time and also had a two blade. Do you really care what prop he had if he made the claim of 84mph and the guy above used a Tempest Plus to validate 76.2? The Docs prop seems to have worked.

never did find out what Big Lou's boat really weighs with one person, much less TWO skeletons

Sure we did, everyone agreed that it was 1600lbs peer Matty with a soda drinking driver of 250 lbs. I think that could drop to 1500lbs when woobs weighs his naked 16 hull and it comes in at 900lbs instead of the 1,000lbs we all have allotted for this Winter time bench race banter. Dr. Lou also said he had to repair the front deck on his 1965 Ski Sporter and the sides a couple of times. What that translates too I don't know.

never did find Osiris

Correct, just not yet!
never did confirm anything really, now did we? :jestera:

Hey finding an additional 8mph will be a challenge and I'm still at 70% (Matty getting the prop info for #452 is key) and would love to be proven wrong but 5 out of 6 of your items above are confirmed. Another guy below, Tito, seems to have a pretty strong vouch for the Super Strangler and Dr. Lou.

Want the first seat out of Missouri on the Kenworth? :jestera:



BIG GRIZZLY I Know Lou and I have seen his 16 outboard run. I have been wrenching on boats since I worked for River Marine in 63, and he may be too modest to tell you, but his donzi outboard blew my 1970 H&M Donzi 16 away. My boat did an honest (and scary) 65 on my gps. His boat has an evinrude V-4 135 that is a factory race motor it has four exhaust pipes the size of softball bats and only a two bladed prop. It sounds like an airplane and it SCREAMS! What ever has been done on that motor is working right. I also was a non believer. He also owns a wicked 45zx and has a SH*T load of toys.

[Just Say N20]

Just curious, and not to hijack this thread any more than it already is, but was Tito's 1970 Donzi 16 running a Volvo e-drive?

I KNOW what it takes to make a Volvo driven old school 16 run GPS 65 mph. In my case it is a trimmable 290 drive, a Solas 23 prop and over 430 hp and 490 ft/lbs. I doubt his H & M engine had anywhere near that much hp, so I'm skeptical of his GPS 65 mph claim.

[Greg Guimond]

I don't really care what everyone AGREED on, I want to know what it REALLY weighs. in my business, we deal in facts, proven documented facts, then we print it out....84 mph with 2 people onboard, and a 2 blade race prop? okayyyyyyyyyyyyyyyyyy. or did it run 84 with the 3 blade? hmmmmmmmmmmm.

so, approx only 25 hp more using the stock 225 Merc upper and lower, over a worked Johnrude on #452 at 205hp, gains 9 mph? seriously?

and you keep telling me i'm wrong? those are your written words, not mine :cool!:


BUIZILLA, I understand man. I know you always want facts. I have seen you provide a ton of helpful information on car motors over the years. I would not even think to challenge that. Now I'm one of the few on this site that has a 16 O/B, so to me (and me only) I'm interested in as many details as I can gather on this topic because it's Donzi 16 OB's. Now, like you with I/O's, I know a thing or three about O/B's. I'm no expert, but I have a bit of "been there", "done that" over the years, including getting spit out of my 16 into the river at 78mph, trying to get 80. Could have died that day but didn't. So I like learning about new or old OB stuff, and trying new things, especially about a couple of old 16s, even if some is conjecture. That said, I'm not afraid to take a position nor learn something that proves me to be looney and wrong.

On the facts I have. My 1972 16 OB weighed 1107 lbs on a digital scale. That's a fact. If you had weighed your 16 hull naked we'd have another data point but you didn't. I had it layed up a touch on the heavy side and it has a several structural add-ons in the hull sides and transom which also added a little weight. The scale weight did not include the front floor, the drink holders, the gas tank, or the wet/dry storage compartments. Everything else was a part of the 1107 pound weight, including the rumble seat hatches which are large. Given all that you know about Donzis, do you really think that either the 1965 hull or the 1967 #452 hull were more than 1,000lbs naked? I don't, that's my position.

On the 1975 16 OB Baby with the 2004 Mercury 225 EFI and TM 1.75 Lower Unit with 4" of fixed plate setback. That 16 hull ran 76.2mph and turned around and took a second pass at 77.7mph with a Tempest Plus 27 wheel not a 28 as woobs used in his calc. I believe the guy did what he said he did and what he posted he did. He further backed it up with a youtube clip that showed 74mph with a full tank of fuel. That's a fact. I believe that he did all three GPS passes, 74, 76.2, and 77.7. That's my position, and I'd be interested in how you think otherwise.

On the facts about the #452 hull with a V6 Johnson. The owner says he did 68mph. I believe him. Go get a prop model and size and then we can agree or disagree.

Now on 84mph, it will always be conjecture. That said, I believe Dr. Lou. I can't tell you how many guys routinely whip arse with older outboards against brand new stuff. New stuff is heavier, with lower RPM limiters many times. Dr. Lou is an educated, well funded guy and his responses to me were always well thought out and full of details. Would I like to have a picture of the title or of the "OB#1" under the dash, you bet captain. Maybe he's taken me for a ride but I don't think so, that's my position.


Ask yourself why guys switched to Volvo E Drives
Ask yourself why guys raise X dimensions
Ask yourself why guys switched to Alpha SS Drives
Ask yourself why Rootsy used an O/B gearcase shell on his drive. Yep O/B case
Ask yourself why

[Greg Guimond]

ask yourself WHY, nobody has ever seen, or verified, Dr Lou, in his 84 mph boat... why? you know he is around, where's the BOAT? with all the communication you have had with him, why no current pic's? why? and, if it exists, which it may, why the secrecy? why? stock 225? not a chance in hell either.. if your talking the one on you tube, as I think you are, that's a highly modified open exhaust mid, we discussed this here before, if that's the same boat

Staying cordial, and I'll give you the best answer I can to each of your points, lets take one of your issues at a time.

First issue you mentioned is weight. I told you my 16 weighed in at 1107 pounds. Do you think that the earlier 1965 or 1967 hulls being discussed weigh 1,000 pounds?

[woobs]

That 16 hull ran 76.2mph and turned around and took a second pass at 77.7mph with a Tempest Plus 27 wheel not a 28 as woobs used in his calc.

Here's the calculation for a 27" pitch prop with a 1.75:1 gear at WOT of 5,750 rpm. To attain 77.3 mph (actual) the slip must be 8%.



27

x

5,750

=

155,250.00

=

84.0


0.92


77.3



1.75

x

1,056



1,848.00

[Greg Guimond]

Just curious, and not to hijack this thread any more than it already is, but was Tito's 1970 Donzi 16 running a Volvo e-drive?

I KNOW what it takes to make a Volvo driven old school 16 run GPS 65 mph. In my case it is a trimmable 290 drive, a Solas 23 prop and over 430 hp and 490 ft/lbs. I doubt his H & M engine had anywhere near that much hp, so I'm skeptical of his GPS 65 mph claim.

Bill, I don't have any idea. It was just a post that I stumbled on in the archives. I don't know if your 16 is in your garage or not but it would be interesting to know as compared to an e-drive how many inches the centerline of the prop shaft on your AQ290 is below the keel.

[Just Say N20]

Bill, I don't have any idea. It was just a post that I stumbled on in the archives. I don't know if your 16 is in your garage or not but it would be interesting to know as compared to an e-drive how many inches the centerline of the prop shaft on your AQ290 is below the keel.

Maybe in the spring. It is unaccessible to me, 45 miles away, inside heated storage for the winter.

I know my outdrive is deep. How deep, I couldn't tell you. I was surprised to see the comparison of Jay's and the other 16, and were their drives were. I swear (from memory) that the top of my drive is below the water surface when the boat is at rest. Another thing to check out this spring.

[Greg Guimond]

what does it matter what a routine 65-67 weighs? a routine 65-67 never ran 84 for the umpteenth time, what does Lou's boat weigh? and where is it? lets deal with the topic facts :lookaroun:

Ok. I was hoping to keep it cordial, which was the tone and intent of my last two posts l but I guess you want to make it a "thing" which is aok with me.

So I guess your goal is to not answer the question about comparing a 1965/1967 to my 1107lbs. You have been following the thread and OF COURSE you know that Lou's boat is not accessible. He provided the pictures of it and that's all we got. Why do you insist on asking an odd question like the one above on a thread that is based on the Docs word? Go over to his house in Florida and shake him down about making up a boat :doh: Then go down to the Keys and shake down the guy who claims to be running a 16 OB Baby with a 225X on the back. Then go over to Boca and shake down that guy who also has an X on the back of his Baby. Then go over to Germany and find the guy who CLAIMS to now own the Doc's 1965.

Let me know when you want to actually answer a few questions, which I'm sure you won't want to do. I'll even go one better, ask me five direct questions and I'll answer all five. In the meantime if you have information about the Merc 225 not being stock (which I don't) why don't you actually share the info with folks? I'll learn something. A new and novel concept for you I'm sure.

Come on man, parts of the thread are based on assumptions, and it's Winter. Have you gone through your whole life without a couple of "what if" scenarios. It's only the internet. Go boating down there and measure your prop shaft depth below the keel. And one last thing, on these boards I go by one premise, what you write you should also be willing to say on the phone or face to face. Which I will be happy to do should we ever have a chance to meet in person. Again, you have been an incredible asset to guys over the years and that helps folks. Try helping on this thread, which I started to have some fun with. Or buy the site and ban me. I'm aok with either outcome. PM me your phone number and I'm sure that we can figure out a better way to interact. I'll take 50% of the blame, but I started this thread and I'll take it forward as I want to even if it is only talking to me, myself, and I :yes:

It gives me something to do in the cold while I figure out how to upgrade my weedeater :idea:

[Greg Guimond]

So we don't get to talk on the phone? Dang it, I wanted to talk you out of that Promax you have sitting idle on a crate. If this is your way of being cordial it's peculiar bedside manner. It's a thread based partially on "what he said", I still don't get what you don't get about that. So then the best thing for you to do is opt out. But before you do can you grab that youtube video from .org and post it so I can take a look?. It'd be cool to see what he has goin on there if it is the same guy I am talking about. Here is the guys GPS of 77.7. I helped him a small bit with the set up and he never said anything about the motor not being stock other than looking for 250 more RPM, from 5500 to 5750 which he bounced off with the limiter clocking 77.7mph

That is my one question of you. It would be helpful to see the video. All these pages of winter banter (3/4's of them me talking to myself) and I have one question that you can help with. You willing?

If it isn't stock I'd like to know what he did before I go upgrading. :wavey:


Now back to our regular programming.........A Torquemaster l/u weighs 47lbs with lube but without a prop. A Turbo Fusion prop weighs 17lbs. That is all I have for facts at the moment.

[Greg Guimond]

Here's the calculation for a 27" pitch prop with a 1.75:1 gear at WOT of 5,750 rpm. To attain 77.3 mph (actual) the slip must be 8%.



27
x
5,750
=
155,250.00
=
84.0

0.92

77.3


1.75
x
1,056

1,848.00





Interesting, the theoretical numbers are about what he claims. I will say that when I got my best stab of 79mph with a Tempest Plus A45 although I prefer the Fusion 4 blade for overall use.

[Greg Guimond]

I know my outdrive is deep. How deep, I couldn't tell you. I was surprised to see the comparison of Jay's and the other 16, and were their drives were. I swear (from memory) that the top of my drive is below the water surface when the boat is at rest. Another thing to check out this spring.

I guess the various AQs might have prop shafts that are slightly different depoths when measured from the keel down to the prop shafts centerline.
I would think at least 8" of depth for those AQs (except the E-drive pictured below) when measured on the trailer squared and level to the keel.

[Phil S]

...what would happen if Ken Burns directed an episode of "Finding Bigfoot" ? :bonk: :biggrin.::yes:

[Greg Guimond]

He'd stumble on the Loch Ness Monster doing 77.7 :biggrin.:

[Ghost]

...what would happen if Ken Burns directed an episode of "Finding Bigfoot" ? :bonk: :biggrin.::yes:

"Finding Bigfoot": a show about not-finding Bigfoot.

[Greg Guimond]

Hey Ghost, why do guys use E drives? What drive and case did Rootsy use to tickle 80mph? ;) What drive are you using on your 16?

[Phil S]

..Buizilla's 16 OB went past me last spring like I was anchored and I run just a tick under 90...

[Ghost]

..Buizilla's 16 OB went past me last spring like I was anchored and I run just a tick under 90...

Due to the weight savings with the 4.3.

[Ghost]

Hey Ghost, why do guys use E drives? What drive and case did Rootsy use to tickle 80mph? ;) What drive are you using on your 16?

Huh? You sound oddly defensive. :).

I literally just think it's funny that the title of the show is the opposite of what happens on the show.

"Dude, that's a squatch. Sounds like a juvenile, from the knocking."

[Greg Guimond]

Not at all, I just don't know why guys use E drives. :biggrin:

[Ghost]

Not at all, I just don't know why guys use E drives. :biggrin:

Just add that to the list. ;)

[Greg Guimond]

Or why car motor guys raise X dimensions :biggrin:

[Phil S]

...no, he was only pulling four skiers...me, just one.

[Ghost]

Hey, how did we forget to factor in the Biscayne Bay vortex?

[mattyboy]

Fly fly

[Phil S]

...who knew it was Fonzi ? :nilly::bonk:

[Greg Guimond]

Ghost, maybe you have some Cray algorithms about a heavy 16 having less drag than a lighter 16 :biggrin:

[Greg Guimond]

Fly fly

Fly Fly don't be shy ........

[Phil S]

Fly Fly don't be shy ........


Draw an arrow to the broken ribs please Sir...

[Ghost]

Ghost, maybe you have some Cray algorithms about a heavy 16 having less drag than a lighter 16 :biggrin:

So, if we take 1000 lbs, plus 287 lbs for the Super Straggler, times (55 minus 21 inch strakes), plus hull452, divided by your Rep Power...holy smokes, bag 84, this thing might be faster than light.

[Phil S]

So, if we take 1000 lbs, plus 287 lbs for the Super Straggler, times (55 minus 21 inch strakes), plus hull452, divided by your Rep Power...holy smokes, bag 84, this thing might be faster than light.

Assuming it's all above the equator...everyone knows this...:biggrin.:

[mattyboy]

Greg
great pic of the speed scrubbing water pickup


without it you can get a little higher

please return your seat backs and tray tables to their full upright position, todays flight will take us over large bodies of water so in case of a water landing your seat cushions may be used as a flotation device.

[Greg Guimond]

Another Winter snowstorm....ugh. Bill (Just Say N2O) has done a great job with his 1967 Ski Sporter 16 pictured below. It looks awesome and runs fast at 65mph.

How come the guy "Roots" with the Sweet 16 was clocking 80mph (I think) with his when both Bill and Roots has almost identical horsepower? Where did the extra 15 mph come from? I was not around back then when Roots had it, the only other one I know of that hit 80 was Parnell's 16 but he had a lot more horsepower. What gives?

:confused:

[Greg Guimond]

Is it possible that the Volvo AQ drives overall dimensions along with how many inches its prop shaft is below the keel can make a 15mph difference on a 16? :confused:

[Just Say N20]

Greg,

My AQ290 was turned in the picture you posted. It would be interesting to see how the line would look if the drive was straight forward.

I don't think I have any pictures from that perspective. I will look tonight.

[Greg Guimond]

No worries. The AQ drives seem to sit low in terms of prop shaft to keel but adding 15mph in top speed? Below is a '65 Ski Sporter.

[mattyboy]

Greg

from what I have seen the AQ length from the shaft to the anti-cav plate changes on some models. the later model were longer than earlier models.

the aq also HATE disturbed water with the props they had in the day the unit is bulky and not real hydrodynamic

[Greg Guimond]

Interesting Matty that the later AQ's like the 290 would be both fatter and have a prop shaft that was further down from the keel. I guess now that I look at the picture of the red one (is that a 1965 AQ200?) as compared to Bill's AQ290 I can see that the bullet on the "newer" AQ290 drive is bulkier. Bigger housing and gear case meant beefier gears and more longevity. The trade-off was a decrease in top speed which I guess is now making sense as to how Roots could go 15mph faster with the same pony power.

[mattyboy]

Greg

keep in mind as the AQs progressed thru their life time the intenals got bigger and stronger

the aq 200 was rated for 200 hp

the 250 for 250hp 270 280 and so on the 290 was the strongest of them all


they were well engineered and took way more then their rating for many many years

[Greg Guimond]

Agreed. As an O/B guy I had not really paid any attention to the AQ series of I/O drives until this thread got me thinking about "drag".

Now that I see the AQ 280 "E-drive" was able to add 6mph to the top end speed as compared to the standard AQ280, it's making some sense to me. If Bill changes over to an AQ280 "E-drive" on his '67 Ski Sporter he goes from 65mph to 71mph due to the bullet being slimmer (2 7/8") and the prop shaft being closer to the keel bottom of the 16. You'd only know the specifics if someone with a Ski Sporter and either an AQ280 or AQ290 measured the distance from the keel to the prop shaft centerline.

My suspicion is that either of those drives prop shaft centers could be as much as 9" below the keel line. We'd have to get a few folks with 16s measure to compare and confirm.

[mattyboy]

Greg Bill

I think what we are seeing on Bills 16 is this.

Bills hull 409 as my hull 410 and jay's hull 420 all came with ford small block power mounted to the eaton badged volvo aq 200 from the factory in spring of 67.

when Jay and I were testing the solas props Jay's 16 did not like the solas 21 it had the power to spin it but for some reason it behaved poorly which was not a feature of the solas. we found that the cav plate to prop shaft center was like an inch closer on Jay's 200 lower than mine cause my 16 had been fitted with a volvo 250 by HM in 1969. All we could figure was the water was bunching up on the plate . Penbroke also confirmed the same space on his aq 200.

Now with Bills boat what Probably happened is they enlarged the existing aq200 cutout , fitted the 290 housing and with the longer 290 it puts the plate an inch or so lower on Bill's 16

[Just Say N20]

I believe Matty is correct. The cut out in my transom is Huge! The final location of the drive (and resultant X-dimension) is simply what they could "overlap" between the 2 cut outs, and have enough transom left to bolt the drive through.

It would not surprise me at all to learn my drive is an inch or more lower than "normal." That could explain a lot. It could very well be that the entire anti-ventilation plate is completely submerged even at top speed. I have never deemed it reasonable to hang over the transom and look WOT. That would be a significant amount of additional drag. That isn't just a plate on the 290. It is large enough for exhaust to exit on non-thru hull boats.

[Morgan's Cloud]

Now with Bills boat what Probably happened is they enlarged the existing aq200 cutout , fitted the 290 housing and with the longer 290 it puts the plate an inch or so lower on Bill's 16

After looking at the photo of Bill's I was trying to get some sensible words together , then I saw what Matty said above.

To me , it looks like Bill's unit is too low . I know , photos can be deceiving , but 'turned' or not it sure appears that way to me.

Back some years when my brother had the Chris Craft XK19 he re-powered it with a new 350 and the mechanic who did the swap found a newer transom plate and outdrive than his original 250/270 that it was made/came with.

I think he went up to a 280 ... Well , the mechanic simply re-used the original 250/270 (or whatever it was ) cutout and as soon as I saw the finished product my stomach turned .The anti ventilation plate was now about an inch BELOW the keel line .
In that swap over he went to a lighter more powerful setup and went no faster at all.

So my suspicion is that Bill re-used his standard cutout (roughly) when he should have raised the whole shebang by an inch+.
In other words, Greg , don't assume that that is the correct/standard height for the 290 unit.

Now , that was all speculation by the way as I can't really see Bill doing that but just my .02c

In the meantime I got the PITA timeout and see that Bill has posted some remarks . It look like I might have been on the money , for once .. :tooth:

[Greg Guimond]

It would not surprise me at all to learn my drive is an inch or more lower than "normal." That could explain a lot. It could very well be that the entire anti-ventilation plate is completely submerged even at top speed.


To me, it looks like Bill's lower unit is too low. I know, photos can be deceiving, but 'turned' or not it sure appears that way to me. In other words, Greg , don't assume that that is the correct/standard height for the 290 unit.

Ahh, making sense now. I always prefer to talk about distance of the prop shaft center below the keel. To me, it is simpler than X dimensions. You could add to that the distance of the anti-ventilation plate from the 16's keel as well. In Bill's case if both his prop shaft centerline and anti-v is 1" deeper, that alone might mean his Ski Sporter could have a 3 mph higher top speed. Now you are say, 68mph with a stock AQ290 depth. Then swap it for the E-drive and you are at 74. That is not far from Roots 81mph.

[jl1962]

Bill-

You thought your drive was below the surface at rest, maybe this is another reason.

I don't have a picture of the boat out of the water w/ the drive down, just up.

But I notice a lot of red hull color below the drive and above the drain plug.

78717

This picture is w/ the 250 lower I bought from Matty.

[mattyboy]

the 200,250,270 and 280 cutouts are basically the same , the 280 T was the same except for holes for the 2 trim lines outside of the cutout. these holes are also outside of the transom seal so they were prone to leaks and rot

the 290 cutout was bigger especially at the bottom to include the trim lines within the transom seal

[mattyboy]

this has me thinking mine may be low as well. My 68 hornet was originally a 289 and an aq200 was retro fitted with a 5.0 and an aq280T in the mid 1990's. When the winter breaks I will have to take some measurements.

As Bill mentioned the plates are shaped differently on the 280 and 290 drives the 200 250 and 270 are solid plates the 280 and 290 are thicker and hollow for the exhaust chamber

[Morgan's Cloud]

Matty , as I said earlier , I can't recall which unit it was that the mechanic replaced the original 270 (or 270 badged 250) with on my brother's old boat but it didn't have trim and it did utilize the original cutout .
It was just about an inch longer though from the crankshaft input line to the anti ventilation plate.
The extra was noticeable to anyone who's a fanatic about keeping the o/d from dragging extra depth .

Just think about all that hidden speed you just might have there ! !
(although correcting it aint exactly gonna be a weekend project )

[Greg Guimond]

The mystery of the 280/290 could be quantified once some propshaft to keel bottom measurements pop up on Ski Sporters. I'm betting that they are 9" deep. Do both the 280 and 290 have anti-ventilation plates that are also hollow for the exhaust to exit? Matty, did you ever get prop info from #452?

[mattyboy]

So does anyone have the tech specs on where the X should be for a Volvo AQ ?


MC I felt visually that the drive and housing looked low on my hornet but I was rationalizing it has well the sides and deck are much higher making it look low. we will see when I re-commission her in the spring.



Greg

look at your pics the 200 250 and 270 all have the same plate the exhaust went thru the top of the plate then out thru the torque tab ( red boat)

the 280 and 290 the plate was thicker and the exhaust went thru the plate and out the end of it. ( the light blue and Bill's boat)


I will get more info on 452 when the owner returns to the island


here is a pic of mine the day I brought her home it does look like when the drive is all the way down the plate may be lower than the keel line

[Greg Guimond]

So does anyone have the tech specs on where the X should be for a Volvo AQ ? the 280 and 290 the plate was thicker and the exhaust went thru the plate and out the end of it. I will get more info on #452 when the owner returns to the island

here is a pic of mine the day I brought her home it does look like when the drive is all the way down the plate may be lower than the keel line

If both the AQ280 and AQ290 all came standard with the anti-ventilation plates cast for open exhaust like your picture, that would produce additional drag, certainly in the midrange. Now a measurement from the keel of a Ski Sporter (or any Donzi model) down to the AV plate and then one from the keel to the prop shaft would give you an apples to apples across the board from 16 to 16 to 16.

You're AV plate looks to be below the keel for sure Matty in the pic you posted, and if you look at Bill's youtube clip underway I suspect his '67 Ski Sporter's is also from the look of the rooster tail at top speeds. The picture below from the archives shows the earlier AQs AV plate to be about dead even but the only one's that matter, at least for this thread, is the 280 and 290 because of the massive thickness of those AV plates. Compare that to the thickness of #452's 210hp Johnson V6 wacker and it looks to be night and day drag wise even if both AV plates were/are dead even with the 16s keel line.

Starts to show you a part of how 1967 #452 could do 68mph with a wacker versus Bill's 1967 16 doing 65 and roots doing 81mph.

[Morgan's Cloud]

If Bill's and Matty's are set up where the a/v plate is in the water breaking off of the keel , even at low speeds ,they're too low IMO.

When we were doing the Magnum project I told the engine supplier (an old race head) that I wanted the unit (a/v plate) 'up' , not level with the keel at normal trim he said that if you're 'level' you're already too low (deep) .
We raised that sucker by about and inch and an eighth .

When I repowered the St T , same thing . The Volvo SX-A and DPS-A have an even bigger through the a/v plate exhaust than the 280 and 290 units.
Now, even when I'm running slow cruise speeds , the water is exiting the keel and under the a/v plate.
No matter how fast you go the spray pattern off of the unit is as clean as can be and the a/v plate is clear of solid water coming off the keel .

[Greg Guimond]

I would agree MC, if the anti-ventilation plate is higher, then the prop shaft centerline distance to the keel will also be higher, and you will go faster pony for pony and burn less fuel in the cruise mode. Of course all of these adjustments are measured in $$ per 1/4" of adjustment which aint cheap.

If the AV plate is too high you get a picture like this one. All show and no go lol :tooth:

[Morgan's Cloud]

If the AV plate is too high you get a picture like this one. All show and no go lol


B ,Bu, But , that's sooo kool :biggrin.:

Actually , for me it's getting the damn a/v plate up high enough to help eliminate unnecessary drag. Everything after that is ok just as long as it's not so high up that you loose the leverage of +trim .

I'll leave the rocket science of the optimum distance between the prop shaft and the keel on any given hull to the ....err .. rocket scientists !

[mattyboy]

my point is that Bill's and Mine were 200s then the newer legs were added. I am sure if you look at a factory installed original 250 270 280 or 280t 290 the hole is higher.

the hole would be set so to set the plate even with the keel.

[Greg Guimond]

It would not surprise me at all to learn my drive is an inch or more lower than "normal." That could explain a lot.


I am sure if you look at a factory installed original 250 270 280 or 280t 290 the hole is higher. It would be set so the AV plate is even with the keel.

Bill had kindly provided a set of measurements a ways back in this thread showing his AQ290. Since no one has an exact measurement yet, I did a quick layout and show the Anti-Ventilation Plate on Bill's '67 Ski Sporter with the 290 to be 1 1/16" below the keel of his hull. That would put the centerline of the prop shaft about 9 3/4" below the keel line. I think I have this all right but hey, I still use an abacus. We will only know if 9 3/4" is accurate when Bill takes out the tape measure next Spring. Just like woobs and 900lbs.

If I'm about right with 9 3/4" then it frames a bunch of performance stats, especially when you add the fact that the AQ280/290 drive is bulky and the gearcase bullet is a big 4 1/2" in diameter. Getting 65 with all that drag is darn good. Go to the standard AQ290 mounting height and you would jump up to say 68. Swap out the AQ290 for an AQ280 E drive and you would jump up again by 6mph to 74.

[Greg Guimond]

Geez, an AQ280/290 L/U's Ventilation Plate is thicker than I ever would have thought based on the pic below ..........

[Greg Guimond]

So back to the baseline questions ...........

1. Can a Ski Sporter 16 with a 275hp I/O and a stock height AQ 280 do 55mph? Yes
2. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 "E-drive" do 61mph? Yes
3. Can a Ski Sporter with 430hp and an AQ290 do 65.2mph? Yes, even with a thick Anti V plate 1" lower than stock and a prop shaft at 9 3/4" below the keel
4. Can a 1967 Ski Sporter 16 with a 1998 Evinrude V6 (210hp-5700rpm) O/B do 68mph? Certainly looking like a yes pending prop data
5. Can a 16 with a 2004 Mercury V6 (225hp-5750rpm) O/B do 76mph? Yes, unless BUIZILLA has a video that shows the Merc is not a stock 225 EFI

How can "roots" Ski Sporter go 81mph with the same 413hp? What's up with that +15mph??

[Ghost]

On #4, how can it be "pending prop data?" Either someone ran it and measured the speed or he didn't, right?

Aside, I think you'll find it's 'Rootsy' not 'roots.'

[duckhunter]

So back to the baseline questions ...........


How can "roots" Ski Sporter go 81mph with the same 413hp? What's up with that +15mph??

Rootsy did it with an Alpha SS. Apples and oranges.

[Greg Guimond]

On #4, how can it be "pending prop data?" Either someone ran it and measured the speed or he didn't, right?

I believe Matty talked to or emailed the current owner of #452 and the owner said he did 68mph. I believe him. I'm not sure when the owner clocked 68 (last year or ten years ago) but Matty is going to find out and hopefully also get a prop model and size which will be interesting to compare against the Mercury 225 that GPS'd 77mph with a Tempest Plus.

[mattyboy]

So back to the baseline questions ...........

1. Can a Ski Sporter 16 with a 275hp I/O and a stock height AQ 280 do 55mph? Yes
2. Can a Ski Sporter 16 with a 275hp I/O and an AQ 280 "E-drive" do 61mph? Yes
3. Can a Ski Sporter with 430hp and an AQ290 do 65.2mph? Yes, even with a thick Anti V plate 1" lower than stock and a prop shaft at 9 3/4" below the keel
4. Can a 1967 Ski Sporter 16 with a 1998 Evinrude V6 (210hp-5700rpm) O/B do 68mph? Certainly looking like a yes pending prop data
5. Can a 16 with a 2004 Mercury V6 (225hp-5750rpm) O/B do 76mph? Yes, unless BUIZILLA has a video that shows the Merc is not a stock 225 EFI

How can "roots" Ski Sporter go 81mph with the same 413hp? What's up with that +15mph??


Greg

going a little a stray here
blurring lines a bit the 16 ski sporter was on it's way out when the aq 280 was coming in there were 16s with the 280 and a few with the 280t they were 130hp and 290 hp volvo a few 235 CC but most were 300 hp CC motors. I think these are all long strake boats but will try and confirm.

there is no 280 e drive the e drive was made during the 250 and 270 era but the volvo stuff is pretty interchangable so it may be possible to mate an edrive lower to a 280 upper

Rootsy was not a ski sporter his boat was a 16 classic and he had an alpha ss with a CLE

and I think if you are measuring the thickness of the 280 plate you need to include the exhaust hump on the 200,250,270

[Greg Guimond]

I hear ya Matty. I'm interested in getting a framework for real world verified speeds so that I can compare that to both #452's 68mph (which I'm 100% on) and Dr. Lou's unverified 84mph which I'm still at 70% on. It sounds like both the 280 and 290 had the thick Anti Ventilation plate (inplate exhaust) and also have the same gear case shape below the AV plate. If you have either of those you are going to go 55mph with 275hp. That I think is very safe and confirmed.

Can I ask if the AQ280 drive is the same shape and dimension as the 290? It looks like it in the picture, but I've never eyeballed them.

[mattyboy]

yes I think the lowers are the same and any changes in the 290 were in mechanicals and connections around the upper.

I'm looking at all the VP docs I have to check they mention a 1 and a 4 inch extension for the drives

[mattyboy]

If you look at the leading edge of the lower above the plate on both the 200-270 style and the 280 290 style there is a crescent shape . if you follow that back you will see the older style is thicker and historically the newer drives are a tick or two faster

[Greg Guimond]

Greg, there is no 280 e drive the e drive was made during the 250 and 270 era but the volvo stuff is pretty interchangable so it may be possible to mate an edrive lower to a 280 upper

I ran across this schematic of a AQ280 "E" Drive, but not sure if it is legit or what years the drawing represents .............

[Morgan's Cloud]

It might be interesting to know the heights , from very top to very bottom , of all these different units . At least the 200/250/270/280 and 290
Or at least , the distance from the power input shaft to the a/v plate.

Based on my experience with what happened after the unit was switched on my brother's boat I have a feeling that there' s a possibility that many have done similar swaps and may now be dragging their a/v plates way too low as there is a little extra length (height really) in the units as they progressed to a higher number .

Matty , I bet you'll be a little shocked if you find yours is too low , and if Bill's is and he's already getting the numbers that he is, just imagine the possibilities ! !
.

[Just Say N20]

I found this picture of my boat sitting at rest, BEFORE it was my boat.

You can see from the waterline, that the top of the outdrive is barely above the water. Really different when you consider the pictures of Jay's posted earlier.

[Greg Guimond]

I found this picture of my boat sitting at rest, BEFORE it was my boat. You can see from the waterline, that the top of the outdrive is barely above the water. Really different when you consider the pictures of Jay's posted earlier.

Below is a clear picture of a 1966 with an AQ270 at rest as a point of comparison Bill as well as some speed details on a 1968 Ski Sporter


Since I don't have a GPS, I borrowed a Radar Gun from a local Police Officer. Jason held the gun,read the speeds, and I drove.....62MPH at 4800 RPM. Remember, that isn't wide-open, as I won't take a chance on blowing the Volvo. She'd turn up to 5000-plus, and without Jason in the boat, and less gas (we ran with full-fuel) I would speculate that it would hit 64-65 or so wide-open.

Specs again ......
Volvo 280-upper
Volvo 250-lower
Grizz's 23 Solas Prop.
347 CID Ford Racing engine;397 HP at 5950 RPM.

Oh yeah, we were running with the drive in the middle slot for the manual trim adjustment. Restrictions are I had mufflers installed. Anyway, there you go.

MB

[mattyboy]

Greg

again a 270 would not be original on a 66

all the edrives I have seen were on 270s if it is published it must have been an option on the 280 but it looks like it only came in the 1.4

[Morgan's Cloud]

I wouldn't put any relevancy on the water line in relation to the top of the outdrive .
It's all about where the a/v plate is in relation to the keel .

And that red 16 is sweet !

[Greg Guimond]

Exactly MC, that is why the term X is misleading. Everything starts at the keel line and you measure down from there. First stop is the AV plate (above, even with, or below) and then the prop shaft centerline.

[Greg Guimond]

Rootsy did it with an Alpha SS. Apples and oranges.

That is actually precisely the point, it is very different. A lot of the boys still shivering in the cold in Missouri I think are going to be surprised as to how much a lower unit's prop shaft distance below the keel and a gear case profile can add to performance. This is a part of the reason the 225 Merc wacker can clock 77mph I suspect. It's not just horsepower.

Take Bill's (Just Say N2O) 1967 Ski Sporter 16 as an example. He goes 65.2mph with the deeper by 1" AQ290. Then look at Rootsy with his 16 Classic and he is running 81 with the same horsepower. The biggest difference is the prop shaft depth and lower unit's overall profile. In between, if you plug a Volvo "E-drive" speedmaster onto Bill's rig he picks up 6mph and goes from 9 3/4" deep to about 7". Gaining 6mph is because of the combination of a higher drive, a more hydrodynamic profile, and a slimmer bullet.

Then Rootsy takes things to the next level with the same horsepower on his 1997 16 Classic and radars 81mph (into the current btw) with an Alpha SS. That lower unit is 2 3/4" higher yet again. My only caveat is that I have not seen anything where Rootsy actually measured his prop shaft distance down from the keel I am pretty confident in 4 1/4". I'm sure the exact is out there somewhere, just as Bill will be able to confirm 9 3/4" depth for his rig when Spring arrives. Remember also that all this is intertwined with where the water pickups are located.

So.......with 420hp

9 3/4" = 65mph
7" E Drive = 71mph
4 1/4" = 81mph

As far as the strake length difference on Bill's 16 (55s) versus Rootsy's 16 (21s) I still do not think they play any major role at the speeds we are talking about and the angle of attack at those speeds of 65 and above. Ghost may have another way to look at this and I'd consider it but so far nothing has convinced me and my abacus otherwise.

** All of this is winter banter is based on wanting to make the 16 go faster and sacrificing some stuff along the way because you are chasing the big # :eek!:

[mattyboy]

who said Rootsy had longer strakes?

[MDonziM]

I didn't go back thru the whole thread but Bills 290 drive was pretty much bolted in where the old drive (200) was. There was no transom work done that I remember. Unfortunately I was not a student of x-dim at the time. Just looking at the transom plate position relative to the rub rail, it looks deep.

[Greg Guimond]

who said Rootsy had longer strakes?

I'm assuming that his 1997 did have longer inner strakes. Either way, longer or shorter would not matter at high speeds IMO, especially at 81mph. It would be interesting if there was a high res picture
of the RootsRig fully aired out like Bill's.

[duckhunter]

That is actually precisely the point, it is very different. A lot of the boys still shivering in the cold in Missouri I think are going to be surprised as to how much a lower unit's prop shaft distance below the keel and a gear case profile can add to performance. This is a part of the reason the 225 Merc wacker can clock 77mph I suspect. It's not just horsepower.

Take Bill's (Just Say N2O) 1967 Ski Sporter 16 as an example. He goes 65.2mph with the deeper by 1" AQ290. Then look at Rootsy with his 16 Classic and he is running 81 with the same horsepower. The biggest difference is the prop shaft depth and lower unit's overall profile. In between, if you plug a Volvo "E-drive" speedmaster onto Bill's rig he picks up 6mph and goes from 9 3/4" deep to 7". Gaining 6mph is because of the combination of a higher drive, a more hydrodynamic profile, and a slimmer bullet.


Yeah roger, I don't disagree with any of that. My comment was an abbreviated attempt to say that comparing Rootsy's boat to a VP boat was apples & oranges. There's no doubt that a deeper drive will run slower (sometimes significantly slower) given similar hull & horsepressure.

Nice thing about the whacker is the [almost] infinitely adjustable x-dimension and setback via jackplates. Makes fine-tuning a lot easier than whacking a new hole in the transom for sure.

Still in Missouri on a 200hp 16 running 84, and all of this fascinating but unrelated Volvo drive discussion hasn't swayed me. Fricking cold out here too, and Buizilla drank the last of the beer yesterday so we're down to a box of wine and some frozen pizza rolls.

[Greg Guimond]

Yeah roger, I don't disagree with any of that. Still in Missouri on a 200hp 16 running 84, and all of this fascinating but unrelated Volvo drive discussion hasn't swayed me. Fricking cold out here too, and Buizilla drank the last of the beer yesterday so we're down to a box of wine and some frozen pizza rolls.

10-4. Think more about the 1967 #452 Ski Sporter doing 68mph with 210hp, the 225 Merc boat doing 77mph with 225hp, and then Witch Doctor Lou claiming 84mph with 200hp. Then add the same type of drive and gear case "what if" to those speeds that is being thrown around on the I/O 16s. And last make Ghost do a beer run.

[Ghost]

As far as the strake length difference on Bill's 16 (55s) versus Rootsy's 16 (21s) I still do not think they play any major role at the speeds we are talking about and the angle of attack at those speeds of 65 and above.

In N2O's 65 mph picture, isn't your estimate that the wetted surface is missing the 55"-inset strakes by 9"? With the 21s, that would put 25 inches of the inner strakes in contact with water. That's a lot, and as a percentage of the wetted surface, if the strakes were successfully knocking the water off the hull, it's a a HUGE amount. Certainly seems like it could make a significant difference.

[mattyboy]

let's keep in mind the newer 16s ( post 1990)are not the same size as the older (pre 1980). The newer one's were taken from a plug of a clone.
so let's leave rootsy's and any newer 16 out of the discussion.

Marshall I am sure when a lot of the aq 200 boats were retro fitted with a newer drive that had trim, the fact that it would fit the hole and it had trim was enough of a good thing that the X never crossed anyones mind.

[woobs]

Check out this Ski Sporter ad.... apparently you could do 40.6 mph! I'm sure that was not on GPS though...
78744

[Greg Guimond]

Greg, all the e-drives I have seen were on 270s. if it is published, it must have been an option on the 280 but it looks like it only came in the 1.4

I agree, there was a 280E-Drive Speedmaster from Volvo. I'm not sure why they would have only offered a 1.45 ratio and I bet the AQ280E was only offered for one year so darn rare.

[Greg Guimond]

In N2O's 65 mph picture, isn't your estimate that the wetted surface is missing the 55"-inner strakes by 9" ?

Yes, correct Ghost. From the picture I estimated 46"

[Greg Guimond]

In N2O's 65 mph picture, isn't your estimate that the wetted surface is missing the 55"-inset strakes by 9"? With the 21s, that would put 25 inches of the inner strakes in contact with water. That's a lot, and as a percentage of the wetted surface, if the strakes were successfully knocking the water off the hull, it's a a HUGE amount. Certainly seems like it could make a significant difference.

It could make a difference. What I struggle with is two things. First, N20's boat is about 600lbs heavier in the stern than Dr. Lou's and heavier than #452 and the 225 Merc OB that clocked 77mph. Since Bill's 16 is carrying more weight at 65mph in the picture I'm sure that there would then be less wetted surface on all three of the O/B boats (1965, 1967, 1975) while running the exact same 65mph. How much less wetted surface is not clear, but the #452 boat and Dr. Lou's fall out right away as they both had the Ski Sporter 55 inners and we already know that even the heavier N2O boat cleared the 55s from the water with ease using nominal trim.

So, the question is really focused on the 1975 OB Baby with the 2004 Mercury 225 V6. It GPS'd a best of 77.7 and BUIZILLA has not yet sent over the video he has showing the motor was modified. That model year 16 Baby has the inner lifting strakes that terminate 21" from the transom. Can/did that hull run on, say 2 feet of hull when fully aired out at 76-77mph? The balance moves rearward a bit because of the wacker hanging off the back. You might have some thoughts on this but my gut says that having run these hulls, with a wackers big trim, it is probable that water cleared much of the 21s and possible that it cleared them fully. It'd be cool to see the science. What would be really cool is to see a clear picture like N20's of a 16 OB Baby at 65 or faster.


The big problem with the 16 Donzi with a small-block V-8 is that the boat is too short for the amount of weight in the stern. The Ford 302 setup is a little bit lighter than the Chevy V-8 setup, and the V-6 setups is lighter still. You can try different props and you may have some success, but what I have found is that bow lifting props for the 16 are not the answer. I've actually had the best results using a cleaver (stern lifting) prop on the Mercruiser powered 16 Donzi. The best results on a 16 will occur when the X-dimension is raised a couple of inches and some weight is removed from the engine compartment. If you can find an Alpha SS, then buy it. That will fix the X-dimension problem. Othewise, concentrate on loosing weight in the stern.

[Greg Guimond]

If the inner lifting strakes play no role at 76mph and above then you are down to one 1976 16 running a fully verified 77mph with 225hp pushing _????_ lbs and one 1965 16 running 84mph with 200hp pushing 1600lbs.

[Greg Guimond]

Sidebar factoid on the Factory 22 Classic OB from a board post back in 2004 ..........


The entire time my friend owned the 22' with the twins (7-9 years) he NEVER had a single problem, ran the living **** of it, while my 454's, 502's, and now my 500 EFI's need CONSTANT care. Also, don't forget the value of the redundancy of the extra motor. How many, even the best of us, have not seen the tail end of a tow rope with just one motor. A 500 EFI at the same price of TWO outboards should be close to the same speed. After 1 NEW 350', 3 454's, 1 496'H.O, 2 500 EFIs, his outboards had more hours than ALL of mine combined! It looks like he was the smart one.

[Just Say N20]

As much as I hate to admit it, there is a lot of truth to what he said. I have owned 17 or 18 boats. The outboards ran. No muss, no fuss.

With one exception, the 350 hp/454 Crusaders in our CARVER, all the other car engines in my boats have been a pain. The CARVER engines are the only ones that I haven't had to mess with, and are also the only ones I haven't had to pull out of the boat, at least once.

I believe the engine in my Donzi now, will be the exception. But I still have a degree of envy of Buizilla's 16. I seriously doubt he will ever have to touch that engine, other than to remove water spots on the cowling after a 200 mile run on about 2.5 gallons of gas. :rolleyes:

[mattyboy]

If the inner lifting strakes play no role at 76mph and above then you are down to one 1976 16 running a fully verified 77mph with 225hp pushing _????_ lbs and one 1965 16 running 84mph with 200hp pushing 1600lbs.


ummm i don't think we have any confirmation on lou's 65 running 84 but we do have Parnell's sweetcheeks a pre 1980 skisporter running in the 80s

and as you quoted Forrest his 16 skisporter with a 302 and a merc 888 drive ran mid to high 60's

[Greg Guimond]

ummm i don't think we have any confirmation on lou's 65 running 84 but we do have Parnell's sweetcheeks a pre 1980 skisporter running in the 80s. and as you quoted Forrest his 16 skisporter with a 302 and a merc 888 drive ran mid to high 60's

For the umpteenth time, we will never have a confirmation of Dr. Lou's 84mph claim. I'm taking the guys word, just as I am with the owner of 1967 #452 saying he ran 68mph.

Excellent point with Forrest, I found that he clocked a best of 70mph on GPS with a stock Alpha SS and 300 ponies. What is a Merc 888 drive? Did Forest upgrade from an 888 to an Alpha SS? There were two Alpha SS gear cases and I believe that neither is as hydrodynamic as an O/B CLE case for a number of reasons.


Alpha SS (1.5:1) on '72 16 Ski Sporter, 302 Ford (approx 290 to 300 HP), Kodiak exhaust system, 23" pitch three-blade outboard motor cleaver. Best GPS: 70 MPH @ 5200 RPM.

[Lenny]

While folks are pondering SBC's and SBF's in these things I thought this was interesting. For sale locally here, 540hp in a 16... Starfire is a local clone of a 16 made years ago...


http://vancouver.en.craigslist.ca/nvn/boa/4299968775.html

and a video

https://www.youtube.com/watch?v=Qf21DQRgj3I

[mattyboy]

not a merc guy

not sure what upgrades Forrest did

the merc 302 188 888 drive was a prequal to the alpha

[Greg Guimond]

So you have the Forrest guy running 70mph with a 1972 Ski Sporter and a stock Alpha SS with 300hp as claimed. Then you have Parnell running 80.2mph with a 1979 Ski Sporter and a stock Alpha SS with 500hp.

Forrest's 1972 is a bone stock hull with standard gas tank size. Parnell on the other hand did some changes to his hull's bulkheads, has a 62 gallon belly gas tank, and made a lot of changes to the interior. All these added weight to his 1979 although the actual bottom and the cutout for the drive are identical in both boats case and both have identical Alpha SS units. One does 70 and one does 80.

[Greg Guimond]

TWO Alpha SS cases? to *my* knowledge, and I could be wrong, there is only ONE true Alpha SS case, right hand or left hand, and that case has the water nostrils in the upper nose bullet. Please educate me, it's real cold out here.. :lifeprese: :biggrin.:

Sure thing, once you educate me by posting the video of the 16 Baby where you said the Merc 225 was modified to get it to pull 77mph with a Tempest+. Stop holdin out, unless there's a second 16 OB with a Merc? :lookaroun:

[mattyboy]

some mid-winter reading on the 18 OB (http://www.lgdonziclassic.com/pdfs/18obarticle.pdf)

[Just Say N20]

Very Intersting read. On many levels.

[MDonziM]

I'm surprised by those 18'/200 ob numbers, I would have bet 65mph. Back around 78-79 I had my 16 down in Sarasota with a 302 / 200 volvo at the time and remember a 16 ob with a 235 evenrude blowing past me...

[Greg Guimond]

Matty, awesome article and thanks for sharing it. Two things jump off the page including where the Anti Ventilation plate is in relation to the keel line and the fact that they picked up amazing speed with a cleaver prop. Below is an excerpt that has some very interesting specifics on the boat including Heinrich's prop handy work back in 1976. Amazing how it sometimes takes almost a decade to prove things out. AirRide got blasted on his post below back in the day.


There were many factory custom small Donzi's built in the 60's, 70's and 80's. Mostly 16's & 18's as yacht tenders, test facility boats, military drones and special use platforms, such as camera boats, etc.

I'll direct you to positive proof on one, and you'll just have to take my word on the many others. In 1976, Johnson & Evinrude introduced their first V-6 outboard. Powerboat Magazine had an introduction article written up in one of their 1976 issues. They highlighted this new 200 h.p. engine on the front cover running out of their Stuart, Florida Test Facility on a yellow & white 18' Donzi, with a D.A. Heinrich modified OMC 3-blade O.T.H. cleaver propeller. At that time, I inquired to Donzi, as I was in the market for one & was told they built two for OMC, but was not interested in building any more. Afterwhich, I bought two 18' 2+3's & then moved on to boats that were much faster. Also unique about the OMC Donzi 18' boats, they were wrap-around interiors, not 2+3's. I still have the issue of PB stored away.
One thing of interest is that your factory build sheet says it was sent over to OMC in 1971. What did Charlie Strang and crew do with the 18 OB for the next 5 years until the Powerboat article?

[duckhunter]

Matty, awesome article and thanks for sharing it. Two things jump off the page including where the Anit Ventilation plate is in relation to the keel line and the fact that they picked up amazing speed with a cleaver prop.


Neat article. Wonder what the author thinks about the new 557s? :embarasse

Interesting that they were all fired up about the 200hp mill making sense for big boats in lieu of inboards. What's old is new again - Boating Mag has been on the same kick for a couple of years because of the new 350hp OBs. Sea Ray won "Boat of the Year" last year for their 37 with Vrods mounted in pods (I think 300s?) and they got decent numbers out of it. It really does make sense if you can get the performance you want without the torque and big wheels of a traditional diesel IB setup.

The speed gained with just a prop change was :eek!:.

[Greg Guimond]

Interesting that no one had been able to substantiate the existence of the factory Donzi 18 Classic OB for 32 years until AirRide did it in the thread below in 2008. That's a long time to spend in Missouri.

So let me now do some figuring using my inverted abacus and the hydrodynamic aspect ratio of the bullet diameter of a 1975 OMC Super Strangler Clubfoot gearcase. The 16 hull was claimed to be built by Donzi in 1965. The sale of the same boat by Doc Jones on behalf of Gerry Walin (name actually on the Title) to Lou Benz was claimed to be done in Miami 1976. Then the run by Dr. Lou of 84mph was claimed in 1996. Do I get to say I'm at year 18 and still have 14 years to prove that the Gerry Walin titled 1965 "OB#1" exists and pulled 84?
:rofl:


BUIZILLA, did you find that video yet of the Merc 225 showing it was modified? Or are we going with 77.7 with a stock 2004 3L 225 fishin motor? That's haulin the mail even in LaLa land. I'll round down to 77mph.
:wavey:


Did Donzi make an 18' 2 + 3 outboard model in 1976?


No....


Well, actually they did. They only made two of them. Just checking in to see if the Donzi pros knew their Donzi history.


i'm farrr from a history guru or a know it all, sooooo, we've heard that 1976 rumor for the last 32 years, yet NONE has ever surfaced, nor has pic proof, owner confirmation, sale confirmation, build confirmation, or documentation.... not saying your wrong, but let's just say i'm from Missouri :) and i'm really not, but, hey, let's pretend...

perhaps your confused and it was earlier in life?


it's coming back to me now, Brownie put a post up 3-4 years ago on D.net about this.... check the archives... something about racing in the 188 dead end canal with it against an I/O boat... timeframe would be '71 or '72 hull but used up to 77-78 by OMC, originally rigged for V4's... boat was stationed at the Stuart OMC facility.... Poodle, ask Brownie, he'll remember.... good memory on AirRide, +1 for him... alzheimer's is a bitch...

[mattyboy]

Matty, awesome article and thanks for sharing it. Two things jump off the page including where the Anit Ventilation plate is in relation to the keel line and the fact that they picked up amazing speed with a cleaver prop. Below is an excerpt that has some very interesting specifics on the boat including Heinrich's prop handy work back in 1976. Amazing how it sometimes takes almost a decade to prove things out. AirRide got blasted on his post below back in the day.


One thing of interest is that your factory build sheet says it was sent over to OMC in 1971. What did Charlie Strang and crew do with the 18 OB for the next 5 years until the Powerboat article?




I would imagine first OMC modified it to an OB, the card shows no sign of special notes or build features so it was just unrigged. then they used it as a test platform

[Greg Guimond]

Does the post below have confirmation? If it's accurate then Rootsy's 81mph 1997 Sweet 16 is carrying about the same 55s as Walin's 1965, #452 and N20's. Would a '97 16 be just inches longer and a few lbs heavier?


Yes, the primary difference between 16 Donzis is the inside or closest-to-the-keel lifting strakes. On 16 Donzis built in the 1960s, the inside lifting strakes end about four feet or so before the transom, where as the same inside lifting strakes on the 16 Donzis built in the 1970s ends about a foot-and-a-half from the transom. But then guess what happened when the 16 was brought back in the 1990s as the "Sweet 16"? Donzi shortened the inside lifting strake to end about four feet or so from the transom, just like it was back in the 1960s! 16 Donzis built in the 1970's handle and ride much differently than other 16 Donzis. From what I can tell, for the same HP and weight, the 1970's 16 Donzis are the fastest of the 16 Donzis, but are the least stable and most sensitive to trim adjustments when running fast.
------------------
Forrest

[mattyboy]

the documentation I have on the newer 'sweet 16' doesn't Jive one says it is 16'8" by 6'10" the other says it is 16'5" by 6'11"

the weight says 1845 so I am not sure how it compares to older 16s

the plans put the inner strakes at 56"

[Greg Guimond]

I'll find out the LOA and Beam width specifics of Rootsy's 1997 Ski Sporter, or any 1995 or newer hull for that matter.

While that happens (and BUIZILLA digs up the video clip of the 225) though it seems like the we have a very interesting comparison given that Rootsy's hull bottom also has 55s for inner lifting strakes. I think that you could probably use his 1997 as another reasonable point of comparison for top speeds as compared to Forrest (70mph), #452 (68mph), Mercury 225 (77mph), and Dr. Lou's (84mph) claim.

[Greg Guimond]

the documentation I have on the newer 'sweet 16' doesn't Jive one says it is 16'8" by 6'10" the other says it is 16'5" by 6'11". the weight says 1845 so I am not sure how it compares to older 16s. the plans put the inner strakes at 56"

Here is the length overall on a 1994 Sweet 16 ............16'7" from the factory. Still have to find width.


I had donzi send me the trailering spec's for the earliest model 16 donzi they had, (1994 i believe). it had on it the overall length of the boat as 16'-7", (not including the outdrive), with the center of gravity at 4'-6" from the end.

[mattyboy]

Here is the length overall on a 1994 Sweet 16 ............16'7" from the factory. Still have to find width.


I have the 1989 plans and the 1994 plans 16 7 is not on any of them

courtesy of the LGDCC Library


1995 specs

http://www.lgdonziclassic.net/pdfs/sweet16.pdf

2007 specs

http://www.lgdonziclassic.net/pdfs/16classic.pdf

[Greg Guimond]

The marketing guys probably just throw down something close. A draftsman doing a layout for a trailer has to be more precise. I have the 22 Classic trailer drawing somewhere.

It sounds like what is becoming pretty apparent is what I had said from the start, how far the prop shaft is below the keel coupled with the profile of the gear case is playing as big a role in top speed as horsepower. Forrest has 300hp and clocks 70mph which is substantial. The only reason he can achieve that high a number is because the Alpha SS is 3" higher and then the case itself is slippery. Then you look at Bill's 16 with 420hp. His 65mph is based in large part on his propshaft being 9 3/4" below the keel and then the AQ290 itself is bulky. But if he popped on an E-drive gear case he would pick up 6mph. You take the same horsepower on Rootsy's 16 and he clocks 81mph. His boat is probably a touch heavier than Bill's and Forrest's to boot.


So how can Forrest get 70mph with 300hp and Rootsy get 81mph with 420hp? They both have Alpha SS prop shaft locations below the keel so that cancels out. An extra 120hp buys Rootsy 11mph better speed which is about right. Now if Rootsy's 1997 is heavier or wider that would hurt his top end a little.

[duckhunter]

The marketing guys probably just throw down something close. A draftsman doing a layout for a trailer has to be more precise. I have the 22 Classic trailer drawing somewhere.

It sounds like what is becoming pretty apparent is what I had said from the start, how far the prop shaft is below the keel coupled with the profile of the gear case is playing as big a role in top speed as horsepower. Forrest has 300hp and clocks 70mph which is substantial. The only reason he can achieve that high a number is because the Alpha SS is 3" higher and then the case itself is slippery. Then you look at Bill's 16 with 420hp. His 65mph is based in large part on his propshaft being 9 3/4" below the keel and then the AQ290 itself is bulky. But if he popped on an E-drive gear case he would pick up 6mph. You take the same horsepower on Rootsy's 16 and he clocks 81mph. His boat is probably a touch heavier than Bill's and Forrest's to boot.


So how can Forrest get 70mph with 300hp and Rootsy get 81mph with 420hp? They both have Alpha SS prop shaft locations below the keel so that cancels out. An extra 120hp buys Rootsy 11mph better speed which is about right. Now if Rootsy's 1997 is heavier or wider that would hurt his top end a little.


Agree with all of that - good rollup. Doesn't help substantiate 84mph on 200hp though! Restocked on bourbon and microwave burritos, because I suspect I'll be filling out my March madness bracket in Missouri... :tooth:

[Greg Guimond]

Agree with all of that - good rollup. Doesn't help substantiate 84mph on 200hp though! Restocked on bourbon and microwave burritos, because I suspect I'll be filling out my March madness bracket in Missouri... :tooth:

Might want to re-think the Basil Hayden, wouldn't want Ghost to be left with it and then have to fight over it with woobs :tase:

You have a 210hp OB clocking 68mph (it's running a fishing lower unit)
You have a 300hp car motor clocking 70mph with an Alpha SS (how many extra lbs is the car motor and I/O versus the wackers?)
You have a 225hp OB clocking 77mph (using a more efficient lower unit)

You have Dr. Lou claiming 84mph, only 7mph faster than than the GPS verified 77mph.

It's all down to +7mph and -25 ponies. I think that Dr. Lou had the secret weapon .............that none of the other speeds above had :hi5:

[Greg Guimond]

But wait, how is it possible that the minute you bolt on this drive you gain 6mph? Look at where the AV plate is, how many inches the prop shaft is below the keel, and the lines of the gearcase.

[woobs]

Sorry, I don't drink Bourbon....

I still think 84mph is more than wishful than anything. Willing it there and positive thoughts will not make it so. Neither will pyramid power, the "Force" or a crazy 8 ball.

Over at Scream & Fly they didn't buy it either (and they are wacker people). IIRC, they related that race boats with the Super Strangler did not hit 84, so there was no way a stock V bottom did.

In our little discussion there have been no real like comparisons, benchmarks or controls. So, with estimates and assumptions backed with non-comparible comparisons and psudo physics (where no laws apply) some might convice themselves (using estimates of the guestimates) of the miracle of the 84. The mind is a wonderful thing.

I'd probably buy the Super Strangler 16 boat did low to mid 70's... and to me that's generous. If someone is standing on the miracle 84; well, I can find some good Canadian beer down in Missouri and I'd even rustle up some back bacon to go with it. Easter is coming and if I'm going to believe in miracles it would not be that Dr. Lou's 16 did 84 mph given the circumstances discussed.

At the end of the day, it's an unavailing discussion as there will never be proof, there is no applicable empirical data and peoples opinions are involved. So, despite the fact it is winter, and that some areas of the discussion have been interesting (and thought provoking) in the context of the miracle od 84... We'll just have to agree to disagree and move on to more productive topics.

[Greg Guimond]

woobs is back!

woobs, you have a fully documented 77mph from a 225. No one believed THAT numerous posts ago. Now if BUIZILLA has a video than all bets are off but I don't think so. So the only question is why can a 225 do 77mph and can a 200 do 84mph pushing 1600lbs. It's closer than even I might have thought at the start of the banter.

Unless maybe you do not agree that the 225 Merc did 77mph? That is a pretty controlled comparison albeit without the CRAY. That boat exists and did it last year. Let me ask, how many inches below the keel do you think the Merc's 225 prop shaft was below the keel of the 16?

[Greg Guimond]

Some food for thought from an independent source. They are using an 18 but the theory is 100% identical for a 16 or a 22. The higher the drive, the faster we go.


I have tested 18's with a 2" raised X-dimension and gained 4 mph. Also tested one 18 with a 3" raised X-dimension and gained 5 1/2 mph over stock. In each case I was able to go up 1 prop size. Gained 300 rpm on the 2" and 450 rpm on the 3" I also noted that time to plane was virtually un-affected


MattM, all of the testing is done with a specially modified Bravo One drive that is cut 3" up, then welded back together from mercury, (not available to the public for sale) then we use the latham spacers to lower it accordingly, 1/2" thru 2" down. Hope this helps you.

[woobs]

Unless you do not agree that the 225 Merc did 77mph?

I have no issues with the 225 doing 77mph as it has been documented. We'll see whether it is stock or not.

Assuming the 77mph stands... 200 HP (if we believe 200 HP) means slower, not faster than a 225. It's not in the X either as both wackers could be set to optimum. I don't believe that a super slippery lower on the Super Strangler offsets the lack of HP (or torque) of the 225 let alone besting it by 7mph. That's just plain wishful.

My position is the SS makes up for some of the deficit to the 225HP and probably pushes low to mid 70's... tops. This also assumes the 21's are no different than the 55's (which I don't believe either but, will concede for arguments sake).

Biggest issue of all is that this will never be proven. I have no issue discussing the pro's and con's of each performance issue and how they may affect general performance but, in the context of the miracle 84...I think that discussion is dead. Why? because it will never be proven.

[woobs]

The higher the drive, the faster we go.

Don't get too carried away as this may be true but, only to a certain point. Like any other performance tuning there will be the law of dimishing returns, and in this case it's probably well before we stick a 5' airplane propeller on and call it an "air boat".

[Greg Guimond]

I have no issues with the 225 doing 77mph as it has been documented. We'll see whether it is stock or not. Assuming the 77mph stands... 200 HP means slower, not faster than a 225. It's not in the X either as both wackers could be set to optimum. I don't believe that a super slippery lower on the Super Strangler offsets the lack of HP (or torque) of the 225 let alone besting it by 7mph. Thjat's plain wishful.

It actually IS the X, or what I prefer to use which is prop shafts distance under the keel and it IS the the Super Strangler gear case profile and diameter. These two items alone have been shown time and time again throughout this thread to matter tremendously and have been discussed often on the board over many years. Guys were killing for E-Drives and Alpha SS drives that were 3" higher, but still 5" below the keel of a 16.

I'll get to the rest of it but time to turn in ........have a good night.

[woobs]

No, in this case you just assume that both boats are rigged and set for their optimum performance (whatever that is). Balance, trim, x height, prop selection.

77mph from the 225 is a pretty respectable number and I'm sure there was set up time involved. It wasn't set up to run slowly. So, let's say it was done right and got 100% out of what was there to get. Likewise we assume the SS was set up to take advantage of 100% of what it had to work with.

There's no question that drag is a factor. It's THE factor. It's what this is ALL about. But you can't compare both at "y" inches from keel. You must assume optimum for each set up (and it will be different). Despite your continued support for the properties of the SS foot, it is not a quantitative fact. It's better, sure...but, by how much?

What you have is 225 HP vs 200HP (or less) where the SS has less drag due to a more hydrodynamic foot. The question is; Does the reduced drag make up for the lack of horsepower in sufficient amount to meet and best the more powerful motor by 7mph.

Even in the match up you have carved out...In my mind the difference in drag will not compensate for 25HP to equal the 225, nor best it by 7mph.

To my thinking the deficit is actually closer to 35HP to equal 77mph and at least 80HP to make 7mph better at 84mph. There's no way the slippery SS accounts for that kind of improvement (to offset 80HP)due to reduction in drag.

You can't prove your point and, you're sure not buying mine. The boat will never be seen again and it's unlikely there's another SS outboard around to test the theories. Let's not make more guesses from estimates and cloud the issues with apples/oranges comparisons. It's beat to death, stated, restated, circled around, shuffled, flipped and restated again. Move on.

[zipper]

[QUOTE= You can't prove your point and, you're sure not buying mine. The boat will never be seen again and it's unlikely there's another SS outboard around to test the theories. Let's not make more guesses from estimates and cloud the issues with apples/oranges comparisons. It's beat to death, stated, restated, circled around, shuffled, flipped and restated again. Move on.[/QUOTE]

I concur.... move on

[Greg Guimond]

Banter lines don't shut down until the temp stays at 50 degrees for 3 consecutive days or ice in the Hudson melts, whichever occurs first :wink: Now for the umpteenth time, there will never be a parasitic drag comparison, nor two boats running side by side, so you're gonna have to embrace that.

[Greg Guimond]

To my thinking the deficit is actually closer to 35HP to equal 77mph and at least 80HP to make 7mph better at 84mph.
.

Curious, what's your logic behind this one?

[jl1962]

I concur.... move on

But it's not even Groundhog Day! ;)

Greg - I think you should find the baddest azz old racing outboard of similar displacement and throw it on the back of the mule.
See what you get! There used to be a sailboat on the Sound called IOMA - stood for It's Only Money, Alice

There also used to be a race boat called FUJIMO - I can't print that acronym, but the first two letters will get you started!

[mattyboy]

But it's not even Groundhog Day! ;)

Greg - I think you should find the baddest azz old racing outboard of similar displacement and throw it on the back of the mule.
See what you get! There used to be a sailboat on the Sound called IOMA - stood for It's Only Money, Alice

There also used to be a race boat called FUJIMO - I can't print that acronym, but the first two letters will get you started!


yeah i figure by valentine's day will we have a warp core or a flux capacitor melt down

the numbers that seem consistant are 185 inches from the edge of the transom to the bow eye then and addition 7 inches to the edge of the nose.

[Greg Guimond]

There's no question that drag is a factor. It's THE factor. It's what this is ALL about. But you can't compare both at "y" inches from keel. You must assume optimum for each set up (and it will be different). Despite your continued support for the properties of the SS foot, it is not a quantitative fact. It's better, sure...but, by how much? Even in the match up you have carved out...In my mind the difference in drag will not compensate for 25HP to equal the 225, nor best it by 7mph.

I believe you are wrong and you haven't even considered RPM to RPM. The difference in drag WILL absolutely and easily compensate for 25hp and COULD equal +7mph to boot. The entire point is how high can you run the gear case and roughly how big is that specific gear case. This is precisely the reason Rootsy chose to deviate from a standard Alpha SS. Ask yourself .........how big is the lower unit on the Merc 225 versus how big is the case on the Super Strangler? Then add, as you correctly point out, where can each be run in relation to the keel line and why?

Actually, as I think more of what you say above, I'm up to 80% that Dr. Lou clocked 84mph. :smile:

[woobs]

Curious, what's your logic behind this one?

The SS has been reported at 185Hp not 200Hp.
Given a whoop pipe trick exhaust, add a believeable allowance of +5Hp. This because you are not working with a raw stock engine but a tuned race unit, presumably engineered to be near the extent of it's absolute capacity. (Racers would do backflips for any mod giving +5Hp)
185Hp +5Hp =190Hp.
225Hp - 190Hp = 35HP to equal the motor output proven to make 77mph on a 16.

Still need 7mph to hit 84.
As a ROT (rule of thumb) of 10Hp = 1.5mph (avg)
7mph / 1.5 = 4.5
4.5*10Hp = 45Hp.
45Hp +35Hp = 80Hp.

Note, in real life you can't just add Hp figures and expect the total to balance (it's usually considerably less). Also, the law of diminishing returns means the last few Hp or mph are not a constant and much more difficult to achieve. So, even with 80Hp extra the target may still not be achieved.

Without empirical data or any kind of actual proof...my numbers are as good as yours. Except, I am not stretching or rounding up. Can we move on now?

[Greg Guimond]

Greg, i'll throw down the gauntlet.... :)

Sorry, I threw down the gauntlet to you on producing the video some time ago. So far you've got nada, nothin. And trust me, owning The Mule, (now proven to be a dog) I really want to see what you got :)

Put up the video, period, or live with 77.7mph on GPS with a picture.

[woobs]

you haven't even considered RPM to RPM.

You can't compare the SS 7,000 rpm with the factory Merc 5,800 rpm figure without also considering their torque curves. Since we have no Idea what power each makes at their WOT we cannot draw any conclusions. We also don't know IF the SS actually turned 7,000 or the Merc didn't rev past the factory 5,800 number.

we can only use the information we have and not what we make up. This is about power vs. drag.

In my books the SS must overcome the effect of an additional 80Hp to even be in the ball game.

Despite being larger the Merc is not a brick. Sure it's cross section is larger and will produce more drag.
Using the merc as control, and the drag given a neutral value of 1... so it's all engine.
The SS making up 80 Hp means the hydrodynamics are responsible for 42% of the power/drag side of the equasion based on a 190 Hp engine.

[Greg Guimond]

Note, in real life you can't just add Hp figures and expect the total to balance (it's usually considerably less). Also, the law of diminishing returns means the last few Hp or mph are not a constant and much more difficult to achieve. So, even with 80Hp extra the target may still not be achieved.

I don't agree with your math on 80hp (get to that later) but your observation on law of diminishing returns at those speeds is factual and nicely stated. That is why I am at 80% for Dr. Lou off a baseline of a factual 77mph for the Merc 225.

[Greg Guimond]

You can't compare the SS 7,000 rpm with the factory Merc 5,800 rpm figure without also considering their torque curves. Since we have no Idea what power each makes at their WOT we cannot draw any conclusions. We also don't know IF the SS actually turned 7,000 or the Merc didn't rev past the factory 5,800 number.

Disagree again. The Super Strangler (and Johnson Stinger GP) has been verified, by multiple sources, to turn 7,000+ RPMs. Al Stoker, himself ran the 8 pumper motor in the 7 hour. As to the Merc, we know for a fact that the motor did not rev past the 5,800rpm in clocking 77.7. For a fact.

[woobs]

I don't agree with your math on 80hp

How many times have you bolted a header/pipe on to an engine with a promise of 10% more power? How any times did it prove to be true?

When you bolt on new injectors 15%, new pipe 10%, computer 5%, K&N filter 5%, new coil 5%, low resistance wires 5%, and fancy-schmmancy spark plugs 5% do you get a 50% increase in output of ANY motor... They may all help but, they work in concert and never simply add up.