I replaced the boat, I didn't want to put drives on that it didn't come with since it was 1 of 29 built. I did a ton of research talked to everybody that knows anything about outdrive's, I even talked to the guy that designed the Blackhawk at Merc. Racing. His statement(It was something new we were trying, it didn't work out as good as we hoped, thats why we don't make it anymore.)I am happy you don't have any problems with it, but your boat is much lighter than mine was and the 25 elimintor that started this thread. I do know how to drive. You are right there is nothing structurally diffrent really from the bravo, thats the problem because of the prop surface the Blackhawk has. I am also not some dumb ass who has no idea how things work, I am a ASE master tech, I own my own motorcycle repair shop, I have built motors(motorcycle) that have won national campionships, and have been racing motorsports for 25 years. Out of the 29 p29's built I talked to about 10-12 of them and they were all having problems some worse some not to bad at all, but all had drives break at very low hours. I didn't tear up the gears as bad as the shafts witch may be the weight of the p29, I didn't talk to the Donzi guy's so I don't know their story, but I did sell my spare's to a guy with a Donzi.blackhawk. I don't want to fight or get people mad I was just offering my advise, that's why we have this site. Everything I say is true and I trust the same with you, it is up to Airpacker to do his homework and make up his mind.

Lapse,which shaft did you break,vertical or one of the prop shafts?
As a side note,I have killed 3 upper gear sets in my bravo hp in 2 seasons(breaks off teeth) so I figure I don't have much to lose trying ther BH setup. Can't be any worse. I have one brand new pre production BH drive and 2 more parts doners just incase. I think I have to try it to see what happens. If needed,I have someone who can custom make me a vert shaft if I go through all 3 that I have.

I was twisting and breaking the input shafts and vert shafts, the prop shafts were fine. Dean at the Bravo shop said the input shafts were allready pretty strong but if he cut down his vert shaft and then have it rolled it would be stronger, but he didn't think they would hold up either. I havn't had a Blackhawk since 2000 so somebody might have the part's to make it last, that's why I said to call around to the drive shop's and ask. A XR drive or Teague may be better or a Bmax if you have over 700hp. They will be a lot more easy to change the Xdim with spacers than moving the whole engine up and down. Good luck.

Would it be possible to put Bravo I lower gears and shaft in a Blackhawk and then put a tall surface piercing prop on the drive? That would probably alleviate some of the stress that is put on the Blackhawk upper. Just a thought.

I'am not sure but would guess no, that would get rid of the whole point of the Blackhawk, the two counter rotating props. A XR or Teague drive with a two inch shorter speedmaster lower with nose cone and a cleaver prop would be a start.But when doing custom work like Airpaker is doing you never know what prop you might end up with, You might start with a 5 blade clever and end up running a 3 blade mirage.

The Blackhawk is basically a Bravo 1 upper with a Bravo 3 lower in it's own case. The reason they put them on 502 MPI motors was that motor was reproggrammed to idle very low to keep idle speeds down. Anyone that owns one knows what I am talking about!

I own a 1995 Donzi Classic with a Blackhawk drive. I would say the drive is just as strong as a Bravo. However, the problem is that when you do get air under the boat it will bite MUCH harder when entering the water.

Also, I will admit that they would not be well suited for Offshore racing at all. The high prop shafts would mean getting air a lot more than a Bravo which will lead to things breaking. However, for the "average" boater that doesn't get big air I think they work well. In a mid sized V they are about 5 mph faster than a Bravo and in Cats I have heard they can be over 10 mph faster! I heard of a 22' Eliminator Daytona that had a stock 502 and a 2-speed tranny hooked to a Blackhawk that was doing over 100!

The reason that they quit making the drive was the market was way too small. Some V-hulls had to be totally redisigned to make the drive work properly. Plus, it was one hell of an expensive package.

My advice to you is if you do get a lot of air under your boat be prepared to drive the s**t out of it. If you don't then hold it wide open and go!

I hope this helps!

Oh yeah, back to your original question I would expect 15- 22% prop slip depending on your hull.

Airpacker, I think Ted at Speedmaster had a blackhawk, last I checked.
After that, their are a pair of new 511cid Keith Eickerts, 727hp that would fit in.....

See you at the season opener.

RT

Rob,yes Ted has a used one. I already have 2 of those as parts doners in case I break the NEW NEVER BEEN RUN one that Raymond found for me at a great price. I don't think I'll bring my 25 to the boys boat weekend again though. That lake is just too small. I might bring my 10 foot cougar cub though if I get the resto finnished in time.