I've been wondering about this for a while. This question is for pleasure boats only (non-race). I see a lot of poeple who want more power, but end up blowing up expensive outdrives. Meanwhile, over on the PB forum, the V-drive guys add all kinds of power, blowers, turbos, nitrous, and don't even worry about the drive system blowing up. Not an issue.

XRs are only rated to 600 hp.

The price of high capacity non-Bravo drives (#6's for instance) is out of reach for most people.

Surface drives are expensive, and use very expensive props, so they are out for most people.

Couldn't V-drives fill in the gap between Bravos and everything else? V-drives can certainly handle the power, 2000 hp or more (used in top fuel drag boats), and the drives system parts cost less than a Bravo XR. Speed capability is not a problem. They run them to up to 260 mph. They can be had with low shaft angles (8* or less). V-drives are low maintenance. Even if the V-drive lost speed compared to an outdrive with the same horsepower engine (which it probably would), I would think you would gain it back and more with the ability to run much more power without blowing it up.

Anyone tried V-drives in an offshore boat (perhaps in the old days), and what were the results?

Michael

Because you need to trim up and down to adjust the ride. You can also have a higher X dimension.

michael,a hydro drag boat,with capsual,weighs 1500 lbs minus motor,and runs on 3 points,one of them is the prop,the other 2 are the bottom of the sponsens.even the slowest capsual class[pro mod]has a very high power to weight ratio,it just wont work in a big heavy v btm boat,but in a small single engine cat,i think it could be made to work,but the arenson surface drive is more suited for larger boat applications.btw,top fuel hydro of today is mor like 5000 hp.some have run in the 4s at 260 mph,a top alcohol hydro is app 3000hp.i know this because i was involved in drag boat racing for a long time.

I forget which rag did it but there was a fantastically documented comprehensive test between 2 identical boats one with a v drive another with an out drive. Both were twin turbo big blocks (Schiadas I think)

Under 100 MPH the outdrive was king.

Less boost per MPH.
Variable trim makes proper angle at all speeds practical, easier to dock, easier to maneuver especially in reverse, waay easier to beach. Easier to load and unload from a trailer.....

Basically under 100 the Vdrive was a biatch.

Over 100MPH things reversed-dramatically.

The V-drive required less boost to run 100+, rode better, was absolutely bullet proof. handled better, you could push the nose down faster with a plate the entire width of the boat and react far quicker than a trim pump to angles

I see tons of V- drives at the river and in Havasu in up to 24 foot boats.

One day I will have another one.


Uncle Dave

Mike, that is unreal power! I don't know how people drive boats that are that fast. I think my speed would be more on the order unblown gas...with a single carb.

Michael

i still have a 18 ft hondo flat,i had a gale banks twin turbo engine in it,took it for a ride 1 day and it almost pitched me out,shortly after that,i sold the motor,i wish i had it back,the good old days!

Uncle Dave, I'd love to see that test, if you ever dig it up again. Very interesting.

Michael

Mee too, I may put a call out on the other boating forums to find it.

It was a really great well executed article.

UD

I grew up on drag boats as well. Some facts. With v-drives you would:
Need more room for the v-drive fore of the engine with access for maintainence. This takes up a lot of interior room. The v-drive would have to be quite a bit forward to allow for a favorable thrust angle.

Need a transmission.

Have a boat that is much harder for the average person to dock with a single.

Less leverage to trim with cavitation plates

Inability to deal with very shallow areas

Much more drag than an arneson(except small tunnel)

I am a fan of them but I wouldn't want one in my large cat over an arneson or an outdrive. Cougar made several 20 ish cats with v-drives that I think worked well.

I think your #'s are off, TFH are running 7000 Hp, with twin shafts and props!