New guy seeking V drive/BBC info

[Fiat48]

I would want a whirlaway on just about any V drive. Certainly on the 110 mph you are trying to obtain. I pm'd the rest.

[U.F.O.]

Ok thanks for helping so far....and thanks for not beating me up for being a car guy. One more question(well, for now....maybe more). The quote about prop slip got me wondering. How does the drive setup actually work in these here boats? Is it just one speed(one gear ratio) or multiple gears as in a street car transmission? And, on the launch, is it just direct drive or is there some sort of clutch system or what? Basically, what causes the prop slip? Is the slip through the drivetrain....or are we talking slip in the water(like tirespin) before the prop grabs enough water to start pulling the boat along?
Im getting the impression that they dont have more than one gear to work with. Cause, when I relate it to a car...one of these big inchers can be built to make explosive torque at lower speeds and still make 650 horses or better at around 6000rpm. This is the hot ticket in a street car and even if torque is lacking at low speeds....having 3 or more gears to choose from really helps things out. However, if the boat on has one gear, which would be equivaltent to top gear in the car....than I understand much more why its good to be able to rev well and gear these things up GOOD. Even with all that torque a big incher can make, a street car would have plenty of trouble trying to launch in drive! I hope that made sense. Thanks again guys.

[Morg]

You are correct, we are talking about the proppeller slipping. As the speed increases clean water is "loaded" into the prop. causing more of a bite.
The proppeler & gear combo. will let you get into the power range of the motor at the hit of the throttle. The guys who have it right will get a very smooth & fast acceleration.
99% of lake boats are running direct drive no trany. I'm pretty sure the alky flats are running a lenco for clutch & another for 2nd gear.
The v-drive is an engage only with a prop. realease.
BTW- on the whirlaway, my old flat did 85mph, my new circle deal does somewhere a little above 100mph. The new boat has the whirlaway & is much "nicer" slowing down. In your application I would not consider the whirlaway as an option. I highly recomend it.

[U.F.O.]

"I see", said the blind man! Now it makes much more sense seeing that youve basically got only one set of gears to work with. One could compare it to a stick driven car(or fully manual auto tranny) who is trying to launch in top gear! I dont care how much torque you make....it aint gonna launch nearly as well in fourth gear as opposed to first!
So, it makes sense that you would want lots of gear reduction to help the launchas much as possible....but then of course you need to spin the rpms up enough to reach the speed you would like to acheive. You guys should become car guys....you cant imagine how much cheaper it is to build one of these motors for a streetcar. You dont need to spend all the money bulletproofing the motor for safe operation at 7500rpm....heck, you can turn 10's pretty darn in a big incher that doesnt need to break 6300-6400rpm, and its cheaper and easier to keep that motor together! Either that or consider trannies for your boats hehe.
Just kidding guys. Thanks a lot for all the info. Now its back to the drawing board so I can give some tips on re-engineering this combo to turn some revs.