Moving engine ahead 11 inches for a tranny

[Greg Maier]

I'm installing an Arneson on my Blackhawk and am trying to decide if I should just move the engine forward to make room for the tranny or if I should go with the extension box and keep the engine where it is. Would this help correct some of the problems that the excessive rocker causes in the Blackhawk? or would it be a huge change that would drastically change the balance of the boat in a negative way? Let me hear your opinions.

[GEOO]

I would Try the Stand off box first.
Bolt's right on. Much easier to try. No need to glass in transom. Engine, wires, hoses ect are all in close to the same location. CG should be fine or better.

[mrfixxall]

I agree with geo,i did a sonic last year and used the stelling standoff box's.i believe thay offer them in differant legnths also.. just inspect the gimble housing serface to make sure donzi didn't use 5200 to seal it to the transm.. if thay did it may pull the gel and fiberglass with it..(sonic seals theirs with 5200)...

[Greg Maier]

Thanks for the response. GEOO, does the Bravo hole need to be widened to fit the transmission in or does the transmission fit completely in the box with just the shaft sticking through the transom?

[Jamesbon]

Greg,
My B/W 72C trans. sits about half in and half out of the transom with the Arneson extension box. Mounted on the tail end of the trans is a "double universal joint" or CV joint with a female splined shaft which accepts the male splined shaft of the drive.

I'm just guessing and don't have anything to back it up, but would think the Bravo cut out would need to be widened.

[Mr X]

I would not even think of moving the engine forward in a Blackhawk hull!
Especially if going with an Arneson.

[Greg Maier]

Nate,

The reason that I am asking is that the Bravo Conversion Kit does not mention having to cut the transom, but I have a BW 72C sitting right next to me and it certainly looks wider that the Bravo cut out. It really doesn't matter to me either way since I'm rebuilding the transom anyway because of rot.

Ted,

I certainly value you expert opinion. The reason that I thought moving the engine would be OK was because of the tremendous amount of natural bowlift that the BH rocker hull has. I thought moving the engine forward might just drop the bow a few inches.

[Mr X]

Nate,
The reason that I am asking is that the Bravo Conversion Kit does not mention having to cut the transom, but I have a BW 72C sitting right next to me and it certainly looks wider that the Bravo cut out. It really doesn't matter to me either way since I'm rebuilding the transom anyway because of rot.
Ted,
I certainly value you expert opinion. The reason that I thought moving the engine would be OK was because of the tremendous amount of natural bowlift that the BH rocker hull has. I thought moving the engine forward might just drop the bow a few inches.
Gerg, thanks for the compliment.
My reasoning is that you will most certainly lose bow lift just by installing the Arneson..... My guess is that the combo of the rocker and the Arneson..... combined with the added speed should all balance out perfectly.

[Greg Maier]

Ted,

Good point. The loss of bowlift from the taking off the Blackhawk Drive hadn't dawned on me. Thanks for the input.

[Cuda]

I can tell you from experience, bowlift is a concern with surface drives. The hulls tend to run "wet".

[mrfixxall]

Greg,,this is what the bravo conversion kit looks like....It comes with a standoff box and all the neet stuff to keep your engine rite ware it sits... & i have some props you may borrow for future testing...

[Greg Maier]

Thanks Mrfixxall,

I have the drive, hydraulics and transmission, all used parts. I couldn't afford the new kit, so I looked for used parts. I will need the box and driveline. Thanks for the offer of props for testing.

[fasttrucker]

What happened to the bravo-3?

[MOP]

Greg the tranny only goes part way into the box look at the inner plate the hole is not the big, I know the engine stays in its original position. If you look there is a fair amount of distance between the back of the bell housing and the transon, compare that to the length of the tranny. Inside the box is the tranny tail end, CV joint and coupler. My local welder said he can duplicate the A box for about $4-500 in like or better aluminum, I would check your local shops to see who has X Navy welders they are known to be the very best. But if you have the bucks the A kit is super!

Phil

[Greg Maier]

FastTrucker,
The Bravo III ran great. Great holeshot, 70mph top end, and great cornering. The Bravo III was just an experiment, I didn't plan to use it permanently. My plan has been to eventually install an Arneson, and the discovery of how rotten my transom was has accelerated the project. Basically, I almost pulled a K-Plane through my transom during that day that we were in Annapolis. As soon as I slowed below planing speed, the boat started to take on water. It almost sank at Red Eyes before I realized what was going on.
So, on to the Arneson. Currently I am restoring my transom and stringers. My deck is stored at Jamie's Shop (Lakeside Restorations) in Wilkes Barre, PA. My hull is in Maryland, and I'm currently working on it. I'm replacing the transom and engine stringers with COOSA Foam (Bluewater 26) so hopefully I will never have the rot problem again. While I'm at it, I'm replacing the fuel tank also.
I would say that in my opinion, if there is any hull that will react well to the Arneson, it will be the Blackhawk. I may be wrong, but I hope not.

[fasttrucker]

Sorry to hear about the rot.What do you think caused it?Was it left outside with water in it?