Glass dave- transom glassing question

endeavour32 · 02-12-2010, 08:36 PM

I want to raise the drive height of my Formula 242. I'm going from small block to big block and alpha to bravo. So seeing that everything is out and and I have to move the motor mounts anyway. I figure I might as well raise my drive height 2" . There was another guy that did this to his boat and had good results. So my question is what is involved in raising the drive. can I just glass in the bottom of the transom? Any input is welcomed. Other than buy a shorty, lol...

fireboatpilot · 02-13-2010, 12:25 PM

Why is the shorty out of the question? Do you have the hatch clearance to raise the engine? Seems like the shorty lower would be the way to go and if it's too high you can space it down. Raise the stock drive too high and then you have no where to go from there. Aren't the engine mounts in the same position for small or BBC? I've swapped them out in cars and never had a problem with mounts and positioning. Isn't an Alpha GenII the same as a Bravo cut out? I try to keep it simple if possible but just my 2cts trying to help. Good luck, Bill.

LAKESIDE RESTORATIONS · 02-13-2010, 01:12 PM

Yes a shorty would be a better way to go in the majority of situations. Then you could retain more hatch clearance & not have to molest your transom other than to add the 2 extra bolt holes required for the B1.. Also with a shorty they come in -1 , -2 & -3" lowers.. Much less grief in my opinion & you can keep the center of gravity lower too..

Jamie / Lakeside Restorations

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endeavour32 · 02-13-2010, 04:36 PM

I know the shorty is the easy way. But its $2000 for a used one or a few bucks and a couple days work. What do you guys think about using a standoff box that raises the drive?

twistedvelocity · 02-13-2010, 05:16 PM

I would go with the shorty.
I do believe a box will be about the same if not more.

scarab31 · 02-13-2010, 05:27 PM

I don't think that you would be able to just glass in the difference that you want to raise the drives either. You would also need re-engineered engine mounts. Not something that I would do on a performance boat anyway. You are changing the dynamics and handling of the hull by raising the COG. Seems like you might be asking for trouble down the road. Go with the shorter drive. My 02.

LAKESIDE RESTORATIONS · 02-13-2010, 05:32 PM

Quote:

Originally Posted by twistedvelocity

I would go with the shorty.
I do believe a box will be about the same if not more.

I agree, no need to reinvent the wheel here.. But if cost is the drawback, then I see your point. However the time & materials to do it right add up to.. Even if it is your own time.. To me sometimes spending a more little coin to have more free time can be good too..

One other thing That I would like to point out is... If you go with the glass work & find you went too high and now have too little hatch clearance or your drive is too high after ward you are not going to be happy. Of course the drive can be shimmed back down, but not the engine. You would have to go thru all of that work again to readjust, or do a hatch mod... . . . If on the other hand you go with a shorty lower & you dont like it, you can shim it down or easily go back to a stock lower & height. It also probably wont be too difficult to unload (resell) your shorty if you didnt like it..

You will ultimately need to do what suits your needs & budget the best, I just thought I would throw some food for thought out there..

Hope it helps..

Jamie / Lakeside

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glassdave · 02-14-2010, 05:22 PM

I see my work here is done.Sorry i couldnt get to this earlier i have been in dispose at the Miami boat show.

As always theres some good info here. I do agree that if you could get your hands on a shorty that would be the way to go but on the other hand theres a lot to be said for sweat equity. As Jamie said at least if you go the shorty route you have the ability to simply switch it back if it doesnt work. As far as filling it in if you choose to go that way as long as the transom is in mint solid condition its not that tough a project and is most certainly in the scope of most do it yourselfers. Most drives are mounted from the factory pretty deep anyways so generally your pretty safe going up a couple inches and moving up the rigging and mounts isnt to tuff a project either. I've got my 34 Scarab apart and I'm pulling three inches out of that one, I'm willing to roll the dice.

Something else to keep in mind is just raising the X by itself may not give you much but will allow you to run more aggressive props. So you have have to do some test and tune runs to dial it in and really take advantage of the props new position. I imagine your old set up ran a Mirage three blade or something like that, you'll hafta dump that for a B1 or the like.

Also i dont have the exact numbers but the Alpha is shorter then a Bravo so you'll hafta take that into consideration and add that to the 2 inches you'd like to get out of this.