Blackhawk on a Classic 18'

[DonCig]

Has anybody tried a Blackhawk drive on a Classic 18'?
I just purchased a 1996 Cigarette 20' with a Blackhawk outdrive and my 1997 Classic 18' has a Bravo 1. Any thoughts on doing a switcheroo?

Don

http://www.donzi.net/forums/showthread.php?t=38233&page=2&pp=15

[Mr X]

Walleye 2 ....Stevie Marr has that set up.......
It is a stable rocket

[Air 22]

Ted...please send me your e-mail. I'm at djeckel@earthlink.net.
I have a question??? Thanks Dwight

[DonCig]

Does anybody know the difference in inches for the X Dimension between a 1997 Bravo 1 outdrive and a Blackhawk outdrive?

Don

[Greg Maier]

A Blackhawk is 8 inches shorter than a Bravo. The 22 Blackhawks had a 2 inch higher X-Dim than the standard 22's. From what I have heard, and from my experience, the X-Dim should even be higher on the 22 Blackhawks, but the engine could not go any higher without modifying the hatch.

[Lenny]

My template from Merc shows a 3" raise in the X-dim on the transom of a Blackhawk drive cut-out. Steves' was postioned by someone that knew where to put it on the 18. I would contact Steve.

[Mr X]

Does anybody know the difference in inches for the X Dimension between a 1997 Bravo 1 outdrive and a Blackhawk outdrive?

Don
All outdrives have the same X-dimension.....its right where the crank shaft center line is.
Do you meen the difference in the length between the X-dimension and the prop shaft?

[MOP]

Below is a back end shot of Steves boat, the X was raised about 3". Get his input on the swap, his boat runs like a raped ape with a stock SB.

Phil

[Rootsy]

Steve Marr or Tom Davis and even Woodsy can give you the scoop... Apparently the gent that actually did most of the design work for the blackhawk told them exactly where to put it on Steve's X18... They listened, it works... beautifully... like just shy of 80ish with a stock 350 mag MPI motor... least the one time i saw it at AOTH II...

J

[Dredgeking]

i love this board because of threads like this.:smileybo:

[Woodsy]

The BlackHawk will work GREAT on an 18 Donzi! The guys have mentioned Steve Marr's (Waleye) boat, and they are right, it runs like a raped ape! Merc 350MAG MPI (300hp) spinning a 1.65:1 ratio Blackhawk with worked 31P props. She turns 77 mph all day long... not bad for 300HP!

Anyway, Steve's boat was setup specifically for the BH drive, and I am pretty sure his x is up quite a bit over stock....

I ran a BH in the stock X on a 22C and it ran great.....


Woodsy Von Outboard

[ChromeGorilla]

I ran a BH in the stock X on a 22C and it ran great.....


This interests me. I've read on a bunch of other threads that the BH didn't work well with the 22c hulll and stock X dim. If you had success and it worked well, I would love to hear your opinion. I was tossin around the idea of a BH on the back of my 496HO and keeping the B1X for when the BH poops itself...

[MOP]

Scott I have spent the better part of a year researching the BH on a 22 and surface drives in general, I am in the slow process of doing the switch. I have had the good fortune to speak with a few that have done very similar setups, I explained my plan and they feel it will work out and like the idea of the mouse motor. My biggest issue is getting enough weight transferred aft as I am running a 383 SB, I am mounting a new tank about 10" farther aft than the new 22's also putting dual batts and all pumps aft. I am going a little different route them most, I am shooting for a fast cruise as I use my boat for work and play. I am leaving the drive at stock Alpha X and going to try to use B3 wheels, I will not utilize the full potential of the drive. My hope is to get some bow lift being a few inches deeper on the X and getting a fair amount of weight aft. I may have propping issues and may have to scout up a set of BH wheels, need to get wet and find out. I have talked with a few that ran shorties with SB's and they seemed real happy, for me time will tell! Maybe you should wait to see if mine makes the grade.

Phil

[Tom Davis]

I did the design work and the glass work on Steve's X-18 BlackHawk conversion. Not sure what would happen if the x dimension remained the same as the current drive. Keep in mind that the length of the boat is a big factor, what may be OK for a 22 may not work at all with and 18. Is the drive thats on there now an Alpha or Bravo? The X dimension recomended by the guy that designed the Blackhawk is higher than most manufactureres (including Donzi) put them on there production boats. Mostly this was due to the fact that the engine would not fit under the hatch. Note on Steve's boat the hatch had to be modified with a hood scoop. Steve's X-18 Project also required splitting the boat to take out any hook and structurally reinforce the boats stiffness, and a complete rebuild of the transom, it's about 4" thick at the drive and tapered and glassed all the way to the hull sides.
If you have any specific questions feel free to contact me, I would be more than glad to help.

Tom Davis
Winni Bandits

[roadtrip se]

is the guy that you all are referring to I believe as the developer of the Blackhawk. Very knowledgable BH guy.
Great guy, I've talked to him several times.

He runs a performance rigging shop now up just a few miles from where he worked at FonDuLac.

Always had all the answers to my questions about the infamous Blackhawk and proper set up.

We don't want to bury this guy with calls, but PM me if you are serious about doing a BH set up and I'll pass you the contact info I have for him.

Todd
"Blackhawk good!"

[ChromeGorilla]

Not to hijack the thread, but after doing searches of threads on the subject, what is the concensus on a BH on a 22c with a BB and stock x dim? The feelin I got from the threads of past was that of no go. Just "curious".... :biggrin.:

[MOP]

No question the drive runs better on the rocker 22 hulls, but a set Arneson rocker plates may have been just as effective. Georges boat ran very flat until he put the plates on, now he can induce a fair amount of porpousing. I have run boat with a rocker and I don't care what anyone says the rocker makes a boat to squirrely for my liking. That being said I still think the BH at the stock X will go faster than a Bravo on the flat bottom 22.

Phil

[Lenny]

MOP, don't you mean rockered 22 hulls?

[ChromeGorilla]

Now when we say faster, 1-4 mph or 7-10 mph..... first result probably not worth it to me. 7- 10....hell yeah I'd be rockin the BH.

[MOP]

MOP, don't you mean rockered 22 hulls?

Yes but I bent the boat the wrong way!!!! Bonnie was crabbing about super. Rocker!!! Damn ain't had a drink to drop!

We used to store the smaller boats in the yard with just bow and sterns blocked and "bent" a few they handled like crap afterwards. This is pretty much indicated by a few BH owners saying the boat is a handful and needs a lot of seat time. There is much talk about no bow lift being the reason for the rocker, I wonder just how true. Read Donzi Blackhawks post below, it is his post that has me cautious about the weight aft issue. From what I have read and heard there were far more straight keel and cat then rocker hull installs. Maybe more can be achieved with props then many think, me I will be happy if mine does what I started out to do. I could care less about top end, if I were going the top end route I would run an Alpha SS which is faster than a Bravo and probably faster than what I will be running. I like the no torque of the duo and I doubt if I will break the BH, all in all I feel I will do just fine playing with weigh and some prop work. My buddie has run what we think my setup will be threw his propping computer, once I get it running he will try to fine tune it for what I want. He is hoping for just cupping and maybe less pitch the 28's I have may be a little much. I think the 28's will work based on what Dave was turning with his 22 using BH 29's, he got 70 at about 4300. I will be making more power and spinning lower pitch and smaller diameter wheels.

http://www.donzi.net/forums/showthread.php?s=&threadid=29224

[Woodsy]

Mop...

The Alpha SS will not be faster than a BH if you have the power to pull the props.... and you should be worried about moving wieght aft....

Gorilla....

I could get into alot of trouble helping out a Yankee fan such as yourself... but seeing how you guys lost in the biggest upset in sports history, I feel kinda bad for ya! Suffice to say, the BH ran great on a 22C with the stock X. I only picked up 3-4mph, but I didn't have the power to spin up the 27P wheels I was running. The 454MAG MPI turned 4300 RPM and ran 71-72 in a small chop... slower in dead calm, faster and faster in the rough.... there was more speed to be had, I just never got around to tinkering to find it. The best part of the BH on the 22C was the lack of torque steer when you re-enter....

Woodsy Von Outboard

[mattyboy]

I could get into alot of trouble helping out a Yankee fan such as yourself... but seeing how you guys lost in the biggest upset in sports history, I feel kinda bad for ya!

Woodsy Von Outboard
Please I'm beggin ya stop with the redsox already :tongue: :)
;) it's the day after the supper bowl I'll listen to pats trash talk but the sox stuff has to wait a week or 2 til pitchers and catchers when first to worst happens very quickly

hey is ted williams still a popsicle????? ;)

and the only thing that will sink faster than the sox in the standings will be MOP if he doesn't get the weight just right :tongue:

[MOP]

Dave I thought you ran 27" BH wheels when you ran this drive when you had it?

Matty good thing I am skinny and don't weigh much thats less I have to put aft! :yes:

[Woodsy]

MOP....

I did spin the 27P BH wheels when I ran the setup.... it would have been alot faster if I could have spun them up to 4900-5000 RPM. I didn't have the fortitude to cut up a perfectly good set of BH wheels. I was going to regear the drive, to a 1.65 ratio, then see what happened as I had a set of all three BH pitch props, 27, 29 and a labbed set of 31's. I just found the OB before I got around to it.

Matty... I think only Ted's head is frozen..... just plain ole freaky for us conservative New England types....


Woodsy Von Outboard

[mattyboy]

Woodsy,
yeah I'm sure ole Ted ain't too happy kinda freaky for down here too ;)

[MOP]

Ahh! I see you corrected the post from 29's to 27's!!! Thank you!!! I based getting the B3 28's on you spinning 27 BH wheels figuring the smaller diameter and no cup would get me through for starters. Oh well it will be awhile before I get to try it out, loads of stuff to get done. But most all seems to be falling into place, hoping for April "HOPING!!!"

Phil

[DonCig]

OK guys, I have told my merc. mechanic to keep the morning of June 30th free to pull a swap of outdrives between my Cigarette and my Classic 18. We are going to put the BH on the 18' and the Bravo 1 Shorty on the Cig. I have procurred a set of 27", 29", and 31" BH props for testing. We changed the drive ratio in the BH to 1:50, so the 27" or 29" BH props should be the ticket. The 29's should give me about 77 mph, or a gain of 9-10 mph over what the boat will do right now. If the combo works I will put some hydraulic steering on the 18' this winter.
In looking at the transom photo of (Walleye 2) Stevie Marr's 18', it doesn't look like there is much of a difference in the measurement between the top of the Merc. transom mount and the rubrail as compared to my current setup. I will try and contact Stevie or Tom to see if I can get a measurement on this dimension. My thanks to all who have offered advice on this project and I will give a detailed report of the results after July 9th. I am so looking foward to two weeks of boating on the LOTO come the end of the month.

DonCig


Currently a member of the little rooster tail club, and working towards membership in the BIG ROOSTERTAIL CLUB. But Robert, I still don't have any rams!

[Mr X]

Don,

I had the privilage to meet and talk to Tom Davis for several hours a couple weeks ago.
He raised the X-dim up quite a bit......so high in fact that the stock engine hatch would no longer work. The bottom of the nose cone on the Blackhawk
is now level with the bottom of the boat using a straight edge.

I am in the process of trying a Blackhawk my X-18 restoration project.

Please keep us posted on your results, it should be very interisting!
http://www.donzi.net/forums/attachment.php?attachmentid=7207

[DonCig]

Ted, as you will see in the picture below, my exhaust tips are within 3/8" of hitting the rubrail. My engine sits 1/2" below the top engine hatch.
I am going to stay with the current engine location. If the Blackhawk works, great.

DonCig

[Woodsy]

Don,

You regeared your BH to what ratio? You will need to slow the props down to have the power to spin them. Your regear should be 1.65:1 drive, spinning a set of 27's.... You won't be able to pull the 27's or 29's with a 1.50:1 drive.... We tried that on Waleeyes boat and it didn't work.... thats with the drive at the right height....


Woodsy Von Outboard

[Lenny]

Man, I can't wait for the results here... :D

Does anyone KNOW where Steves' X dimension on the transom was located?

It certainly is not at the 14 1/2 - 14 9/16 standard. What is his X-dim location? Merc suggest starting 3" higher on their template and going from there :eek:

[roadtrip se]

Think IMCO shortie bro...

All current parts...

All current props to try...

Start with a 3-5 mph gain and let the upgrade party begin!

RT
"The Afflicted..."

[DonCig]

David, please help me understand the difference between the following two prop/gear combinatiins and the net result.

1.65 drive with 31" props equates out to 75.8 mph with 15% slip.

1.50 drive with 27" props equates out to 72.25 mph with 15% slip.

Thanks,

Don Tamm

[Woodsy]

Don...

Fiist off, your not at the right X, so the props will be deep (for BH Wheels). I don't know if you measured them yet, but for giggles, but a BH rear next to a mirage+! They take some power to spin, especially when the drive is set too deep.

Now on to Steve's boat....

His drive is set at the proper height. I think he spins 4900rpm at WOT. He is using a 1.65:1 BH, with 32P wheels. (They were originally 31P's). This means his props are spinning at approximately 2970rpm. He sees 77.8 on GPS all day long. If you plug those into the prop calc, he is seeing about 13.5% slip at WOT.... Not too shabby for a surface drive.

Back to your issue. To a certain extent, the slower you spin a propeller, the better your slip ratio is. At idle, BH wheels have almost zero slip, hence the 6-8mph idle speed.

You want to spin 27P or 29P BH wheels set deep with a 1.5:1 drive. That means all things considered, with the same 300HP 350 MAG, at 4900 RPM, you want to spin the 27P props approximately 3267RPM. That approximately a 297 RPM faster than Steve spins. Thats a huge difference. And your drive is set deep. Its going to be difficult.

We put a 1.5:1 drive on Steve's boat. He lost alot of zap, the motor would not pull the props to 4900 RPM at all...

Woodsy Von Outboard

W

[Lenny]

Don, you have a 12 degree transom. Here is an old X-dimension cut-out pic from Merc. As you can see the stock suggested for the Alpha/Bravo on our transom is 14 1/16". DONZI does the Classics at 14 1/2".

Merc suggests a starting point of 17" for the Blackhawk on our transoms. That is why I would like to know exactly WHERE they put Steve Marrs'. The Blackhawk has an 8" shorter distance from C/S centerline and propshaft. With this as a guideline, you can see that the propshaft centerline will be about 11" HIGHER than a stock location BRAVO/ALPHA on the 18. :eek:

[Mr X]

Ted, as you will see in the picture below, my exhaust tips are within 3/8" of hitting the rubrail. My engine sits 1/2" below the top engine hatch.
I am going to stay with the current engine location. If the Blackhawk works, great.

DonCig
Don,
I think I understand......thats how I built my boat too...
Good luck with your project.

http://www.donzi.net/forums/attachment.php?attachmentid=7208

[Mr X]

Poodle,
I was surprised that it was still there in the morning! :biggrin.:

[DonCig]

In my experience, a boat will run the fastest with a higher numerical drive ratio assuming you can find a prop with enough pitch to limit the engine to the desired RPM at full throttle. This does not take into account any handling or bow/stern lift issues.

The theory is that the faster a prop rotates the more power it takes just to turn it in the water. A slower turning prop with more pitch is more efficient than a faster turning prop with less pitch even though the calculation for theoretical speed is the same for both.

The chart on the left shows the prop shaft speed for a given engine rpm/drive ratio. You can use it to see the effect of changing drive ratio, without changing the propeller pitch. The difference between a 1.36 drive and a 1.5 drive is about 10%, or 500 RPM at 5000. If your boat was running 5000 RPM with a 1.5 drive the prop shaft RPM would be 3333. If you were to change to a 1.36, find the same (closest) prop shaft RPM in the 1.36 column and you see that the engine RPM would drop to 4500. As each inch of prop pitch is about a 200 RPM change, you would have to go down 2 1/2" in pitch to pull the same RPM. Our prop calculator (http://go-fast.com/Prop_Slip_Calculator.htm) will help with this math.

The overall ratio is a combination of both the upper and lower ratios combined. In the case of a 1.5 Bravo the upper is 32/27 (1.185) times the lower at 19/15 (1.266) = 1.50.

The downside to a higher reduction in the upper is that there is more torque on the lower gears, vertical shaft and prop shaft. In the case of a Bravo there is also more load on the gear floor.

http://go-fast.com/sterndrive_gear_ratios.htm

Posted by DonCig, copied from go-fast.com

[blackhawk]

Don, you said you were going to re-gear to a 1.5? What is the current ratio?

[blackhawk]

Todd, sounds like he already has a shortie on the 18.

[txtaz]

Nice boat to your left there Ted :) :) :D
If that's his 22, I should have held out....Nice boat, yours too Poodle from what I could see.
Ted, You have snail mail.
Wes

[DonCig]

Scott, the BH was a 1:65 ratio, but during the rebuild of the unit the Merc. mechanic regeared it to 1:50. I am going to give it a go, if it can't spin the props properly I will switch it back to a 1:65.


Don

[blackhawk]

Ah, you were rebuilding anywy. I thought you were re-rearing just to try this. I think you'll be fine with the 1.5. Like you said, a 1.5 with 27s is pretty close to 1.65 with 31s. Actually the 1.5 and 27s will be easier to spin.

You can do the math and the comparisons to other boats all day long, but the reality is you won't know until you try. You have the drive, you have the boat and it's a quick and easy job. JUST DO IT!!! :D

Keep us posted.

[DonCig]

First report!!

THE Cigarette loved the Bravo/Imco shorty combo. Picked up 5 mph and planing and handling and docking are very good. Running a 1.65 with a 28 pitch Bravo @ 5000 rpm at 73 mph. Great rough water boat.

The classic 18 likes the BH once we got the shifter to work. Thanks MOP!!! We have it working but not as smooth as it should. We have had reasonable success with the the 1.50 ratio in the BH but we are going to drop in some 1.65 gears this thursday. So more to come. The cornering capabilities of the BH are wonderful !
And yes, the 18 is faster with the BH over the shorty. More testing and reports to come.

DonCig

[Mr X]

Great news!! Thanks for the info Don. I sent you a few pics of the 26 last week.

Let me know if you want to try it.

[MOP]

Don I hope you wrote down or are keeping mental notes on what the 1.5 did and will let us know the difference. Even though the Beast is a 22 I am watching this post and hoping to glean some good info, I am also very pleased with the handling of the drive. You can do high speed turns in either direction with no difference in roll up and so far I can not cavitate the wheels in a turn believe me I tried, a major and very pleasing improvement over the Alpha which I thought handled great. Will have a set of BIII 22's on Thursday hoping for good results on mine, still will like trying the BH 27's. I think dumping half the blade area going to the BH would have some pluses.

Phil

[DonCig]

My Final Report is still a few weeks out, but here are some initial findings on my switching the BH outdrive from my '96 Cig 20' to my '97 Donzi 18' Classic.

While there has been a lot of discussion about X-Dimensions, the truth of the matter is that the X-Dim. is only a single component of the final dimension, and that is the location of the propshaft centerline in relation to the keel bottom. Yes, the X-Dim. does have an effect on the C/G on the boat, but this subject is probably above our expertise as layman. The reason that the X-Dim. is relevant is that most outdrives did not have the ability to vary the propshaft to keel dimension as of a number of years ago. It requires the use of drive spacers or shorty's which have recently become popular and available. Another way to vary the X-Dim by + or -1" net is with a Stellings Extension Box. A Blackhawk (from now on termed BH) uses a one piece case that does not allow a drive height adjustment without a Stellings extension box, hence the need to get the X-Dim. right the first time, since you are cutting a hole in the transom. Merc. reccomended an X-Dim. that was 3" higher than a Bravo 1, but they also stated that you could raise the X-Dim. on a BH up 4.5" with proper testing. Your risks were the loss of steering control and the loss of a good feed supply of un-airieted water to the engine.
The risks of to low of an X-Dim. were the loss of top speed, and the possibility that the torpedo could enhance stern lift or stern steering.
Merc. reccomended that you make your adjustments in small dimensions (.250" per change) and document the results.
I know that my BH is currently located in the range of 1" to 3" deeper than I could use to obtain top speed. But I also know that there is a sweet spot some where in that range that is still to be discovered.
My current setup idles at 6 mph with the minimum throttle setting and a 1:50 ratio, 27" props and 660' in altitude at 90 degrees and 70% humidity. Fast but not untolerable by the wake patrol.
I was able to get up on plane quite easily on a large slalom ski behind my BH 18, but the wake was a little rough , so I lengthened the ski rope out to 90' and found some clean water. When I put 4 adults and one 115# child in the boat, planing time was longer than I would like.
I have posted a few photos to help those that are interested in this program.
I can say that I have gone faster with the BH than either the Imco or the Bravo, but until the rest of the testing is finished I will withhold my conclusion.
For those that are intrigued, I found that my BH had no issues in confused waters and that it cornered harder than the IMCO or the Bravo.

Thanks to all that have helped and may we all enjoy the thrill that the Donzi classic boat line brings.

p.s. - The LOTO Donzi dealer (Big Thunder)), when seeing my boat at the gas dock said "these have always been my favorite boats!" , he said it all.

[DonCig]

Some more photos.

[MOP]

Don what RPM and speeds have you been able to attain so far? I am still mucking around with BIII wheels, just got a set of 22's had them machined but have not run it yet have been to busy. My last try with a set of 24's was atleast decent, hole was good and cornering handling is much improved like you discribe. I hope to get a run in today or it will have to wait until I get to 1K.

Phil

[GEOO]

Thanks for the photo's. Interesting Stuff.
I didn't relise the BH prop shaft was so much higher then the shorty.

[DonCig]

Geoo, a Blackhawk prop shaft is 8" closer to the X-Dim. than a Bravo 1, so with a -2" shorty attached, the Bravo 1 would be 6" deeper into the water than a Blackhawk outdrive.


DonCig

[DonCig]

Phil, the BH outdrive repeatably produced the following numbers with the 1:50 ratio and the 27" pitch props. The next step is to put in the 1:65 gears and try the 29" and 31" props for comparison.

3,500 RPM 52 mph 13% slip
4,000 ROM 60 mph 12% slip
4,600 RPM 69.5 mph 11% slip

I expect to hit 73/74 mph with the 1:65 ratio.

DonCig

[roadtrip se]

Don,

Great pics!

Connecting the dots on the Stelling extension, a couple of thoughts...

Do a search here on "land and sea", I remember seeing some posts on this a year or so back. Might be some nuggets here from that experience with a stern jack, which does put the drive further back in the water kind of like an extension box.

Gimbal strain. The BH puts an enormous amount of stress on the transom assembly. Moving that drive out further via Stelling will accent this. Time to start thinking about steering, to offload some of the stress, if you decide to stay with this setup. 70+ mph is also a good excuse!

Keep going man, cool project. Let me know if I can offer some more bad advice.

RT
"I 'm so close to 1000 Islands, I can smell it, GONE!"

[MOP]

Thanks Don!

[Tom Davis]

Interesting to watch this thread develope! Lots of good input.

Let me just say this about the "X" dimension on Steve Ma's X-18

On page one of this post MOP posted a picture of Steve's transom with the BH freshly mounted in my shop.

Note: the BOTTOM of the torpedo (housing the prop shaft) is even with the bottom of the boat when the boat is level and the prop shaft is parrallel to the bottom of the boat (neutral trim).

Estimated from the pictures above that the BH is still about 1.5 inches too low....

Just my .02

Tom Davis

[blackhawk]

Don, like I said, you've got the drives so try it! Did you get the shifting problem solved?

Also, on the extention box. Remember that when you add the box it also has the same effect as LOWERING your X 1". So, getting a box that let's you raise the X 1" puts you right back where you started.

Keep us posted on the 1.65 runs!

[Rootsy]

I'll be interested in seeing how the 1.65 runs... when the SS broke last summer i replaced gears and went to a 1.47 from a 1.59 (yes oddball outboard gearing combo). instead of losing what i figured would be 400 rpm i lost more than double that... and there is nothing wrong with my motor. I now run even rpm's with a very similarly setup 18 w/ SS running both his and my props... i feel that the 1.65 is a better ratio for torque output to the prop. Tradeoff is increased torque at the prop which stresses parts to a greater degree... with the alpha and a stout sbc this is a concern. not so much with the bravo... i am note taking for upcoming "projects" :)

[Woodsy]

I have no doubt the 1.65 gearset will work better than the 1.50 set. The question is how much better?

Woodsy Von Outboard

[blackhawk]

I agree. The 1.65 will accelerate quicker with the 27s and raise the rpms. But will there be more top speed with any of the props and the 1.65? Only one way to find out!!! :D

[DonCig]

Two things:

waleyetwo has agreed to take a measurement from the bottom of his exterior transom ring to the bottom of the keel to compare with my attached picture which shows a dimension of 4.0" on my boat. The Cig measured 4.875" on this dimension. I am guessing that Steve Maar's boat will measure around 5" to 6" on this measurement.

I have scrapped the idea installing a Stellings box because I do not want to remove the engine to pull out the Merc. coupler.

DonCig

[DonCig]

Steve just measured his boat and came up with a measurement of 6.5"/7", so he is currently 2.5"/3" higher on his X-Dim and propshaft dimesion than I am.

DonCig


Two things:

waleyetwo has agreed to take a measurement from the bottom of his exterior transom ring to the bottom of the keel to compare with my attached picture which shows a dimension of 4.0" on my boat. The Cig measured 4.875" on this dimension. I am guessing that Steve Maar's boat will measure around 5" to 6" on this measurement.

I have scrapped the idea installing a Stellings box because I do not want to remove the engine to pull out the Merc. coupler.

DonCig

[DonCig]

We successfully installed the 1:65 gears last week and spent one day on the water breaking them in. Shifting issues are all gone. Due to the 6,000' eleavation here in Colorado, I will have to wait until PK in Sept. to confirm the top speed change with the new gears.

DonCig

[DonCig]

With the engine pulled, we had a chance to measure the X dimension accurately.
I measured my 1997 Donzi Classic 18 with a stock Bravo 1 from the factory and my X dim. is 14.5" as measured by the "tape measure" method.
I had the 350 Mag MPI Gen+ engine with the stock Merc. silent choice exhaust system and my transom tips are 14.25" apart and the exhaust hole centerline is located 1.5" above the Gimbal stud reference line.

Ted and Lenny, thanks for your help on measuring this dimension.

DonCig

[Lenny]

Don, why don't you glass that hole in and re-cut the assembly in at 17 1/2" ?

THAT will get you running. :D

The BH 22's have the same "x" dim (14 1/2") as measured on the 18, (from the actual hull bottom) the only difference being that 2" is "missing" from the original 22's hull bottom, hence why the exhaust tips end up in the rub rail.

[Rene496]

DonCig,
I hope everything goes well with your project. I am very excited that I do not have to sell my BH. My wife and I were able to keep the Donzi and still reach our goals. I can't wait for spring to make some roost.