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Offset
05-31-2011, 01:03 PM
I have a 22' Classic with a 454 Magnum. Much of our boating in the past has just been cruising a little over idle and puttering along. However I wonder with the design of the Classic hull is there an optimum cruising speed for fuel efficiency?

I realize that there are many factors in what is perhaps a simplistic question. Prop, drive and gear ratio and the motor itself. Weight in the boat I would think critical as well.

Anyone ever done any testing on this?

Have a great boating season everyone.

Ghost
05-31-2011, 01:19 PM
Others may have real experience or measurements.

I'm guessing that despite the large range of factors you mention, peak miles-per-gallon would come between 27 and 33 mph. (Rationale: my experience is that most efficient speed is the slowest speed once the hull planes out well. In the lower 20s, I suspect a 22 Classic is still squatting too much, wasting fuel. So somewhere from upper 20s to low 30s would be peak.)

Further guesses:

Your peak MPG will fall between 2300 and 3000 RPM.
Your peak MPG will be somewhere in the ballpark of 3.6 MPG.
Anywhere from about 27 to 33 MPH, your MPG won't vary a whole lot. Whatever RPM first reaches a happy, non-squatting plane, to about 500 RPM more, will be ideal. Above that the dropoff will start much more significantly.
Trimming the drive up/out as much as possible without porpoising or other adverse effects will be most efficient.
If you take some solid RPM measurements and GPS speed readings, you can probably calculate the answer pretty closely. BoatTest has plenty of data for your motor, with Floscan gallons-per-hour measurements at 500 RPM increments. So if you dial in at 2000 RPM and record your GPS speed, then dial up to 2500 and do it again, on up through 4500, you can use the BoatTest fuel consumption data to figure pretty good estimates of miles-per-gallon.

I'm interested in anyone's real-world experience or measurements that susbstantiate or refute any of these guesses.

Walt. H.
05-31-2011, 02:23 PM
Do exactly what Ghost suggested, that's the best advice explained in the simplest manor for just about every boat.:yes:

osur866
05-31-2011, 02:45 PM
Mines not a 22 rather a 18 and I can tell you anything under 3,000 RPM's will be much happier on the gas gauge, fuel consumption is gonna go way up 3,000 and above!

zelatore
05-31-2011, 03:33 PM
Ghost pretty much nailed it.

For any planing hull you'll see the best economy at very low speeds, then a big dip as the boat comes up on plane, then it will generally improve somewhat as the bow drops, then it will steadily get worse as the speed continues to increase.

When I'm training new owners on larger boats, I usually simplify it down to 'look at your wake - the bigger it is, the worse your economy'.

That an over simplification, but it helps them visualize the 'bad spot' where the boat isn't fully planed off yet. It's easy for them to understand that pushing all that water can't be good.

Pismo
05-31-2011, 03:45 PM
2500 rpm/34-35 mph with a MPlus 25" prop in a 22 was the highest mpg in the Powerboat Mag test. 3.2 mpg with an HP500. I would think a little better with a 454.

craigdskilling
05-31-2011, 03:51 PM
Mine's a 18, simple don't open the 4 barrel carb.I can run all day at 2700 to 3000rpm at $30 maybe.

MOP
05-31-2011, 04:49 PM
@3300 doing 43 mph gps I get a tiny tad over 4 mpg, that is just before the back barrels open it is also 22 but with a 383 SB.

Phil

Offset
06-02-2011, 05:34 AM
Thanks to everyone for your knowledge on fuel consumption.

Carl C
06-02-2011, 08:08 AM
You bought the wrong kind of boat.....:nilly:

Pismo
06-02-2011, 08:19 AM
The quadrajet was great for fuel consumption. Those tiny front barrels. If you did not get into the secondaries, it would use little gas. If you did get into the secondaries then it would use a ton.

Rumblefish
06-02-2011, 08:48 AM
As I set out for a lunch run I tell the wife.. " its a 40 mile run so im going to take it easy and save fuel"

I plane out at 3000 .. trim er up watch the rpms climb to 3300 and set back the rpm to 3000..

Aaaah this is great im thinking.." we could cruise all day like this I tell her"..

Minutes later my hand is without my knowledge pushing forward on the throttle, as the sound increases so does my joy for cruising 50-55mph and now I have chosen to get there faster instead!!!

After all thats why I love my Donzi....

Offset
06-02-2011, 09:21 AM
You bought the wrong kind of boat.....:nilly:
Carl, I sold a high performance outboard to buy the Donzi. Based on years of experience with that boat (and several others) I wanted something with some freeboard so the smallest wave would not soak everyone on board. I wanted something that would handle rougher water that was comfortable and if need be get us home quickly. I wanted a boat that I could afford that was quality built and retained some of its resale value that was trailerable. Above all I wanted a boat that looked good.
While I like to go fast like everyone else I do enjoy just idling along enjoying the sights. Speed at least for me is not what it is all about. So based on that what boat should I have bought?
If I have the knowledge of how to save a little fuel that just means more time on the water. That was my reason for asking.:thumbsup:

glashole
06-02-2011, 09:52 AM
is there any real world numbers on using more fuel to run faster

but using less fuel fbecause the boat is running for less time

Ghost
06-02-2011, 10:53 AM
is there any real world numbers on using more fuel to run faster

but using less fuel fbecause the boat is running for less time

A good point. If I understand the question correctly, I think examining everything in miles per gallon takes care of this. You can go at idle for ten times as long, with very low burn. You can go at WOT in no time flat. Reducing to miles per gallon takes care of the time difference, giving you the fuel burned to cover the distance.

On to the question, for real world numbers, I think the optimum usually remains the slowest speed where the boat has planed out happily with the bow down, but with the most trim it will take. Commonly around 3 to 4 miles per gallon in small single engine boats like Donzis. With I/O performance boats, I think WOT gas mileage usually drops between one third and one half from peak. 40% is probably a decent guess for any performance boat. So, maybe 1.8 to 2.7 miles per gallon for things the size of classic Donzis. I think this compares favorably with inboards and other less-sleek designs, which suffer more from hydrodynamic inefficiency at higher speeds. (The "pushing a brick" syndrome.

To add some color around your point (faster with greater burn rate, but for less time), consider an example of a 23 degree deadrise 23-foot performance boat I just pulled off BoatTest:

Peak mileage at 2500 RPM, 27.8 miles per hour, 8 gallons per hour, 3.48 miles per gallon
WOT at 4800 RPM, 62.4 miles per hour, 32 gallons per hour, 1.95 miles per gallon
So, at WOT it was burning gas at 4 times the rate of the best cruise. But the boat was going well over twice as fast. So WOT gas mileage dropped about 44 percent from the peak.

I think this is very typical. WOT sees 4 times the burn, more than twice the speed.

zelatore
06-02-2011, 03:06 PM
Again, Mike is pretty much on the money.

At very low speeds where the boat is down in the water and acting as a displacement vessel, you'll have the highest possible economy for most boats. But few people want to run at 3 to 5 knots. (not sure what hull speed would be on a 22' hull, but very low). For a typical planning hull, economy is best just after achieving a full plane. With gas motors, the fuel burn rate will rise faster than the speed does. In other words, the economy will drop. Especially with carb'ed motors, you'll typically see a drastic drop as the secondaries open.

On diesel boats, I often find that once on plane the speed and fuel burn increase at near-liner rates. Running them at WOT may give economy within 10% of the 'best cruise' of just on plane.

Offset
06-02-2011, 03:33 PM
Again guys your input is very much appreciated.

gcarter
06-02-2011, 04:06 PM
[quote=zelatore;602933] (not sure what hull speed would be on a 22' hull, but very low). quote]

Should be about 6.1 knots.

Ghost
06-02-2011, 04:50 PM
...I often find that once on plane the speed and fuel burn increase at near-liner rates...

Yikes, you really are a big-boat captain. ;) (I know you meant 'linear', but sorry, I just couldn't resist.)

Up to now, I have been ignoring everything below planing speed. This discussion got me interested in peeking at the mileage way down there. Glancing at a couple of examples, it looks like something in the 5 knot range actually may get slightly higher mileage than peak mileage on plane. I suppose it might be even better than slight, if you dialed it in just right. The data I have all have 500 RPM intervals, and down at those speeds, there might be a big difference in optimum hidden between two data points. All that said, it's usually much ado. Unless you were trying to limp home on limited fuel with no hope of help. And even then, if you didn't know the currents, or if you had an adverse wind, it could easily blow-out the MPG relative to higher speeds.

Carl C
06-02-2011, 05:24 PM
Carl, I sold a high performance outboard to buy the Donzi. Based on years of experience with that boat (and several others) I wanted something with some freeboard so the smallest wave would not soak everyone on board. I wanted something that would handle rougher water that was comfortable and if need be get us home quickly. I wanted a boat that I could afford that was quality built and retained some of its resale value that was trailerable. Above all I wanted a boat that looked good.
While I like to go fast like everyone else I do enjoy just idling along enjoying the sights. Speed at least for me is not what it is all about. So based on that what boat should I have bought?
If I have the knowledge of how to save a little fuel that just means more time on the water. That was my reason for asking.:thumbsup:

It just seems that if you are content to cruise around 30 mph that you could have bought any number of small run-abouts with less power. I have a need for speed. I cruise at what conditions allow. Sometimes as high as 80 for short periods. I average 2 mpg and I don't worry about it.

Marlin275
06-02-2011, 11:03 PM
this is a very important subject
sometimes!

Posted 07-30-2005, 06:43 PM

My marina was closed for gas and my backup marina had a fuel spill
and closed down while I was waiting.
Question, when you are running out of gas, is it better to go 1100 rpm slow or 2800 rpm on plane ?
How do you go further, fast or slow? I thought keep the carb on two barrels not four.
I ran out about a mile away, at 2800 and now I wonder?


http://www.donzi.net/forums/attachment.php?attachmentid=13571

http://www.donzi.net/forums/showthread.php?t=41138

ChromeGorilla's answer:

Ok I am copying this out of a BOATING mag I have sitting here on my desk. These are the #'s they got testing a 22 Classic with 496HO.

RPM_____MPG_____MPH
1000 ----- 2.2 ------- 6.7
1500 ----- 1.6 ------- 8.5
2000 ----- 2.9 ------- 19.9
2500 ----- 3.3 ------- 33.4
3000 ----- 3.1 ------- 41
3500 ----- 2.8 ------- 49.8
4000 ----- 2.2 ------- 57.3
4500 ----- 1.9 ------- 64.8
5000 ----- 1.9 ------- 70.5


Looks like I would be best running at 2500 to make sure I made it to the fuel doc.

Ghost
06-03-2011, 11:34 AM
Two marinas out?! That just sucks.

It'd be interesting to see more detailed data on speed and fuel burn down below 1000 RPM, for reasons I mentioned in my earlier post. There might be an optimum around 600-700 RPM that was up near or above 4 MPG, which the data above won't show.

Where I think it gets really interesting at slow speeds is with current and/or wind help, you might jump up to 5+ MPG, or fall down close to 1 MPG. I doubt most of us would know without GPS true speed over ground, suggesting the 30 MPH approach might be best most of the time.

The last interesting wrinkle that leaps to mind is running angle and fuel tank geometry. My fuel pickup is mid tank, such that I suspect I have an accidental "forced reserve." If I am up on plane, with the bow up a little, I think I could run the fuel down below the pickup, fall off plane, and have a little bit left. My guess is some boats are the other way round. If the pickup is at the rear, you might need to stay on plane or you might run out by slowing down. All depends on the shape of the tank as well, which can be hard to know.

GBond
06-03-2011, 03:05 PM
Big yawn..... :biggrin.:

jstrahn
06-03-2011, 03:16 PM
this is a very important subject
sometimes!

http://www.donzi.net/forums/attachment.php?attachmentid=13571


At least you got a really cool pic out of the deal! :)

Carl C
06-03-2011, 03:37 PM
this is a very important subject
sometimes!

Posted 07-30-2005, 06:43 PM

My marina was closed for gas and my backup marina had a fuel spill
and closed down while I was waiting.
Question, when you are running out of gas, is it better to go 1100 rpm slow or 2800 rpm on plane ?
How do you go further, fast or slow? I thought keep the carb on two barrels not four.
I ran out about a mile away, at 2800 and now I wonder?


http://www.donzi.net/forums/attachment.php?attachmentid=13571

http://www.donzi.net/forums/showthread.php?t=41138

ChromeGorilla's answer:

Ok I am copying this out of a BOATING mag I have sitting here on my desk. These are the #'s they got testing a 22 Classic with 496HO.

RPM_____MPG_____MPH
1000 ----- 2.2 ------- 6.7
1500 ----- 1.6 ------- 8.5
2000 ----- 2.9 ------- 19.9
2500 ----- 3.3 ------- 33.4
3000 ----- 3.1 ------- 41
3500 ----- 2.8 ------- 49.8
4000 ----- 2.2 ------- 57.3
4500 ----- 1.9 ------- 64.8
5000 ----- 1.9 ------- 70.5


Looks like I would be best running at 2500 to make sure I made it to the fuel doc.

Why didn't they just bring you some gas?

joseph m. hahnl
06-03-2011, 06:01 PM
Your boat travels at 25 MPH for 2 hours and burn's 12 gallons of gas.
My boat travels at 50 mph for 1 hour and burns 12 gallons of gas.


We both traveled 50 miles on 12 gals of fuel, only I guy got there an hour before you.
I'll start the party for yah :beer::rock::thewave:


http://media.2leep.com/176973-140.jpg (http://2leep.com/news/176973/133/1/)

DonziJon
06-03-2011, 06:28 PM
Everybody THINKS MPG. That's automobile think. Rubber on the road..no slip. In a boat it's GPH..(Gallons Per Hour)..at some RPM.. which YOU must decide by experimenting.

Every LEADFOOT drives a boat in different ways. :nilly: :nilly: DJ

joseph m. hahnl
06-03-2011, 07:44 PM
Everybody THINKS MPG. That's automobile think. Rubber on the road..no slip. In a boat it's GPH..(Gallons Per Hour)..at some RPM.. which YOU must decide by experimenting.

Every LEADFOOT drives a boat in different ways. :nilly: :nilly: DJ


It's all relative . If your driving 25 knots for 2hrs and you burned 12gals of fuel it is 6 gal per hour. If you drive 50 knots for 1 hour and burn 12 gal of fuel it is 12 gal per hour. :drive:

So like I said ,I'll start the party with out yah:beer::rock:
:thewave::woot::band::drinkbeer::drool::pimptwo::a lky::drunk::puke::doh::spit::hi5::fam:

Carl C
06-03-2011, 08:50 PM
And I'll have things going when YOU get there.....http://i51.photobucket.com/albums/f384/cuaiu/smiley/party.gif http://i163.photobucket.com/albums/t300/IRINA006/Smiley/party.gifhttp://i36.photobucket.com/albums/e3/SweetMamaShay/partysmiley.gifhttp://i36.photobucket.com/albums/e3/SweetMamaShay/partysmiley.gif

LuauLounge
06-03-2011, 08:58 PM
I've always used GPW, GPM or GPY. Gallons per week, month or year. That way it sounds much better. As we normally boat on weekends, I find the cost of fuel, yearly, is much less than the slip space.
In 40 years of boating, fuel is just another line item in the overall cost of owning a boat and not a very large one.

Marlin275
06-03-2011, 09:33 PM
Why didn't they just bring you some gas?

That's the Fire / Rescue patrol that docks at my launch ramp.
I was only a mile away and the current was running 3-4 mph
towards the ramp
they got me there quicker than the tide.

They saw me paddling to shore
I made sure I was close before she shut down.

They run on diesel
so no gas rescues.

roadtrip se
06-04-2011, 09:41 AM
My Formula SS 370 with twin 496HOs gets better fuel economy than my Donzi Classic. I discovered this pretty early on with the cruiser. No formal calculations really, just a quick comparison of how much fuel went into both boats at the end of last season.

And as for the first person to the party cove, at least with the cruiser we can start the party on the way there! :yes:

Walt. H.
06-09-2011, 02:41 PM
this is a very important subject
sometimes!

Posted 07-30-2005, 06:43 PM

My marina was closed for gas and my backup marina had a fuel spill
and closed down while I was waiting.
Question, when you are running out of gas, is it better to go 1100 rpm slow or 2800 rpm on plane ?
How do you go further, fast or slow? I thought keep the carb on two barrels not four.
I ran out about a mile away, at 2800 and now I wonder?


That is the exact reason I always carry 2-one gal plastic safety gas containers under the rear bench seat storage area of my 18 footer for when I need that little extra insurance to make it back home, or to assist someone else with those two gal's of gas rather then having to hook up and tow them in.

On my 27-ft Chris Craft I added a auxiliary 22-gal fuel tank I can switch to for the same reason if wind and tide or weather conditions cause a change in my estimated return trip fuel needs, besides in the event the fuel stop I planned on making was closed or out.

I've never run out of gas to this date yet since the 1960's but i've gotten nervous too many times and prayed a little as I adjusted my throttle hoping not to alarm or upset my passengers even though I might have changed my tone of conversation as I kept a nervous eye on that gas gauge.
Now it's such a nice reassuring feeling to know I can turn a manual fuel valve and push a electric fuel gauge rocker switch and watch a bouncing to near empty gauge needle go back to full even though it's only one 1/4 the size of the main tank.
Also that extra 22 gallons of gas in the storage side of the starboard engine compartment bulkhead now helps counter balance the boat sit even at dockside from the 20 gal's of freshwater stored mid-ship area on the port side which use to cause a slight list to port.

Anyway boats are like airplanes, you can never have enough fuel on-board unless you're on fire!
WH

Just Say N20
06-09-2011, 04:21 PM
Super clean installation, Walt. Very nice added safety margin.

Walt. H.
06-09-2011, 11:52 PM
Super clean installation, Walt. Very nice added safety margin.
Thanks Bill for the kudos, but unfortunately thanks to the new obama gas prices this year the big boat won't see any use this season and will be staying high and dry on the trailer in doors at home this year since I had to cancel my slip at the marina, because I just can't afford running it with an average fuel mileage of 1.5 to 1.8 mpg at best conditions with what fuel is going for on the water these days and when I go out I like to keep going and not just for 20 minutes and drop anchor so my daily outing is usually anywhere from 50 to 120 miles round trip at least.

And i'm not like some that pay for a boat slip and are content with leaving it stay tied to the dock and read a book or chat with a neighbor while the slime/scum line grows all season long from lack of use and 24/7 exposure to constant stray dockside electric causing electrolysis to eat the sterndrive assy away. Ugh!
If I wanted to do that I can pull it out of the boat barn each morning and push it back in at dusk, then walk back to the house and pretend I have waterfront property. :bonk:
But I will get to use the 86' cvx-18 since it's a trailer queen and can get almost 3-X's the fuel mileage but has none of the creature comforts except a helluva lot more speed, or i'll just play with one of the handful of vintage old Evinrude rowboat motors I have on my not ready to use 1957 13-ft plywood Lugar runabout and just putt around the shoreline on the Hudson and drown some worms on a hook.

Sweet little 16
06-10-2011, 11:38 AM
you would think that rescue and tow boats would just bring gas with them .
just a word of caution, loading gas out on the water in NY from one "vessel" to another via portable gas cans can be considered a "transfer" which can only be done by a "minor" or "major" facilty with the correct permits according to NYS nav law regarding petroleum and petroleum spill control. The DEC will set you everywhich way but loose if you cause a spill that way. That is why you'll see marinas that don't sell gas have strict rules about coming to the marina with red cans and filling the boat at the dock .If a spill is cause that way it is the marina that is held accountable as well as the spiller. I would also imagine that the rescue guys would be turned into dial- a- gas if they set that precident.
Hello harbor rescue can you send over the big red boat with some gas for me?
environmentally sound thinking but really it is the state looking for income off of permit fees and tax on gasoline.

ralph crocker
06-10-2011, 11:51 AM
I too have a 28 Magnum Maltese with twin 383's (70 MPH) And a 22 Classic with a slightly built 454 (67MPH). At cruising speed about 30 mph they both seem to use about 10 to 12 gallons per hour.

Walt. H.
06-10-2011, 02:02 PM
you would think that rescue and tow boats would just bring gas with them .
just a word of caution, loading gas out on the water in NY from one "vessel" to another via portable gas cans can be considered a "transfer" which can only be done by a "minor" or "major" facilty with the correct permits according to NYS nav law regarding petroleum and petroleum spill control. The DEC will set you everywhich way but loose if you cause a spill that way. That is why you'll see marinas that don't sell gas have strict rules about coming to the marina with red cans and filling the boat at the dock .If a spill is cause that way it is the marina that is held accountable as well as the spiller. I would also imagine that the rescue guys would be turned into dial- a- gas if they set that precident.
Hello harbor rescue can you send over the big red boat with some gas for me?
environmentally sound thinking but really it is the state looking for income off of permit fees and tax on gasoline.

I completely believe every word you say but so far every marina I know of small and large in my area that doesn't sell gas, you will always see a few of their customers carry down from their vehicle a red 5-gal jerry jug or those larger 12 to 25 gal gas caddys on wheels that have a hose and nozzle valve to add fuel to their boats, sometimes they will make a few trips during the week to save .50 to .60 cents per gal and no one comments not to do so nor have I ever seen forbidden by law signs.
I guess where I am bureaucracy hasn't reached us yet north of NYC, at least as of last year I can say.

Tow outfits like Sea Tow must then have those fuel permits since they do advertise that they offer fuel drops to members that run out of fuel whether it be gasoline or diesel as well as battery jump-starts to avoid a time consuming tow.
Heck' you can't even work for them unless you have a Capt's license with a tow indorsement, and to think I use to do straight and side tows as a young teenager with our shop workboat for customers that broke down when I worked at a combination boat-yard and dealership starting back in the 1960's, and now a bureaucrat with the stroke of his pen passing a law say's i'm not qualified to do that anymore, which would be pretty cool part-time job now that i'm retired.

Today Noah would not have been permitted to build his Ark as we know it because of all the B.S. bureaucracy that's in place today requiring permits and inspections as well as licenses to show you're qualified......

Way too much Govt, in out lives and growing!
WH

Ghost
06-10-2011, 02:38 PM
Agree completely.

In some ways this stuff is fascinating to me even when viewed only from a systems perspective (rather than , say, a political or philosophical or moral one). A metaphor may make clear what I mean, where it is probably pretty fuzzy so far. But before that, I just want to say I am not pushing any political perspective in this post, but rather just examining the dynamics of systems, in the context of what was discussed already.

Take insecticide resistance as an example. Regardless of how one feels about bugs, or chemicals that kill them, or whatever, the system that includes large numbers of bugs reproducing but being beaten back with chemicals, will over enough time produce ever more resistant forms of bugs. No stances or beliefs on bugs or chemicals are debatable or relevant, it is simply the unsurprising math of what you get in this system. The most resistant bugs will survive and breed.

Likewise, if you look at the laws, and how laws are made, and who makes them, a similar sort of system operates in a fairly predictable fashion. Voting in elections comes from large numbers of relatively uninformed people who don't know much about the details. Further, the machinery behind the making of what is in the laws, the devil in the details, is made by small numbers of highly interested and organized people. They know they must market their laws to the voting masses, but they also know those masses don't pay attention to the details.

The quite predictable result is Wonderland, where up is down and down is up. Most laws are created claiming to benefit the masses (by way of the marketing I mentioned) while instead doing the opposite (benefiting the organized few at the expense of the masses).

In this particular case, they would argue that the laws that preclude Walt from doing some towing are protecting the public from lousy and dangerous operators. Instead, the laws are usually created by the organized existing operators, to protect themselves from competition with folks like Walt. It's really quite simple. Their primary interest is limiting who can compete with them. When they get the chance to write the law, that is what the law will do.

Again, I am focusing strictly on the predictable systems analysis of this, just as with the dynamics of bugs interacting with insecticide. I won't discuss the particulars of any political theory or philosophy--there are other places for that.

gcarter
06-10-2011, 04:32 PM
Mike, I like your bug analogy. It seems the "Powers That Be" will only regulate things to allow actions to be the minimum that sort of works.
Your statement about ever more hardy bugs is true. If DDT were still allowed, many if not most of the world's most deadly diseases could be irradicated in just a few years.
Let's be bold!
Ban, or outlaw, complacency!

biggiefl
08-10-2011, 11:49 AM
Picking up a 22' friday so I have thinking about economy as my current ride is a 19' Boston Whaler with a 115 Suzuki 4 stroke which at 25mph cruise fetches between 5-6mpg which aint too shabby at $4.50/gal or so. My 240 Sport Baja had a 454 with about 400hp on an alpha 1.32 drive and at 2500-3500 it got the same MPG for the most part about 3.5. Anything over 3500 the 4bls kicked in and you could watch the needle go down. The 22 with a 330hp which is 600lb lighter, carries 50 gal less fuel(another 350lbs) and is less wind resistant should fetch around 4 or more in these ranges. 2900 rpm is about 40mph from what I read and should be about 10gph. My baja fetched 35 at 2900 and 10gph so 3.5.

Pismo
08-10-2011, 02:33 PM
Did you buy a boat to save money??:wink:

biggiefl
08-14-2011, 01:29 AM
Gotta save some coin so I can buy a new $500 cockpit carpet :)

Dr. David Fleming
08-14-2011, 01:40 PM
Enjoyed the reference to the law making - couple of you guys should run office! That or start preaching on Sunday morning! Always wondered about the gas transfer and the fuel spill issues. I like to run my old 1929 Johnson Sea Horse 32. Whenever the carburator drains or flushes it just goes down a tube into the lake. When I fill it by can from the top of the engine and its full - it just spills over and drains into the lake. Old engine is grandfathered into the legal system and excluded from modification by its early manufacture date. Up is down and down is up!

Seriously, the magazine specificications you are accessing here are part of what boat engineers develop in what is called a - "Running Performance Curve." This graph usually shows the engine power and torque as well as fuel consumption all at the same time - also incluced are the frictional resistance to the boat performance - which is basically the drag. By looking at the "running performance curve" you can see how the drag goes up with speed and where the fuel consumption of the engine is at any speed as well as the power and torque. Or you can just do it in your head by watching the gas gauge go down depending on how fast you are driving.

Boat mags find this sort of stuff fun to print to fill up their pages. They get if from the manufacturer or just develop it on their own.

Ghost
08-14-2011, 02:29 PM
...The quite predictable result is Wonderland, where up is down and down is up. Most laws are created claiming to benefit the masses (by way of the marketing I mentioned) while instead doing the opposite (benefiting the organized few at the expense of the masses).

In this particular case, they would argue that the laws that preclude Walt from doing some towing are protecting the public from lousy and dangerous operators. Instead, the laws are usually created by the organized existing operators, to protect themselves from competition with folks like Walt...

...Again, I am focusing strictly on the predictable systems analysis of this, just as with the dynamics of bugs interacting with insecticide.


Enjoyed the reference to the law making - couple of you guys should run office! That or start preaching on Sunday morning! Always wondered about the gas transfer and the fuel spill issues. I like to run my old 1929 Johnson Sea Horse 32. Whenever the carburator drains or flushes it just goes down a tube into the lake. When I fill it by can from the top of the engine and its full - it just spills over and drains into the lake. Old engine is grandfathered into the legal system and excluded from modification by its early manufacture date. Up is down and down is up!

David,

My sincere apologies up front if I have missed your point. Quite honestly, I admit I am unclear on what you are saying here.

But the reference to my use of "up is down and down is up" in the example of your old outboard being allowed to dump gas in the lake, free from legal regulation seems like a mis-application of my use of Wonderland. Further, of course, there are plenty of laws that make that dumping of gas illegal, regardless of whether your outboard itself is made illegal altogether. Meaning, just because they haven't banned it, doesn't mean they haven't banned it from being allowed to dump gas in the lake.

So I thought it worth clarifying what I was saying, in case I had caused any confusion.

I was never saying all laws were bad. Such as laws against pollution. What I was saying was that many laws are written in the guise of protecting the public, when in fact they are actually written, and serve, to protect businesses from competition.

In short, looking from a systems perspective, when Fred makes a law, that law will benefit Fred.

And I say this not to push any political position (people from all sorts of political perspectives take advantage of the tools I describe). I say it simply to address what we saw in Walt's example: he is extremely competent to do some work, but is prohibited from doing it. The result is that the people who are licensed to do it are likely less competent and more expensive than Walt, but protected from competing with him.

And likewise, anyone who would like to start "GasCanBoatUS.com," handing out small amounts of gas to those who have run out, HUGELY cutting into the needless towing fees for those are simply out of fuel, is similarly prohibited from doing so. Not because it benefits the public, but because it benefits those organized businesses who paid to get their noses into the tent when the laws were passed.

And thus, like one of the most notorious examples, liquor licenses, a great deal of marketing goes into convincing the public that liquor licenses protect the public from the evils of bad operators. But in reality, liquor licenses largely only have the effect of protecting the folks who are already in the club from further competition. And this is their true purpose. The exact opposite of what they claim. This is the intentional Wonderland of which I spoke.

Anyhow, as I said, I wasn't sure what you were really saying, so this may have been a needless post. But if there was any confusion about what I meant, I hope this unmuddies the water. And I hope I have not come off as being combative or worse--that was not my intent and I mean no offense. I simply was concerned that I had been misunderstood, and wanted to clarify what I meant in my earlier post, this medium being very susceptible to such things.

And if there was no confusion, in the squeaky words of Emily Litella, "never mind." :)

Regards,

Mike

BUIZILLA
08-14-2011, 04:37 PM
< looks around for the fog horn :lookaroun: >