V-Drives in 27-30 Ft. Offshore Performance Boat?

[Sangster]

Those are "Arneson Surface Drives"....BIG BUCK STUFF..

[Morg]

Nope. Arnesons have the vertical (trim) & horizontal (steering) cylinders. & the cylinderical mount.
These were locked into a non moving strut. You could see the stainless prop. shafts under the boat.
The Arneson's also have the gear box which raises the output shaft to line up with the crank of the motor.

[RiverDave]

First of all: I love V-drives; love how they drive/steer/ride. I love the smell of 'em.
But, one of the issues with a v-drive is: the propeller is at an angle. This is especially true in a V-Bottom. So, V-drive boats have a tendency to lift the stern and push the bow in. On a longer v-drive boat, this is exacerbated by leverage. It would take a lot of horsepower and engineering to overcome a lot of these limitations.
For example: 24' Spectra v-drive; 1400 hp (twin turbo bbc) back in the day ('79) ; running av-gas; tuned everything -- went 80MPH ONCE at sea level, and then melted the pistons.
It didn't break the v-drive, though. ;-)
There's a few 24 Spectra's that run alot better then that. Parnelli's old boat ran in the 90's with a 1000 HP if memory serves correctly.
RD

[Tom Brown]

One thing you don't want to do is run twin outboards on a 27-30' boat. The performance, fuel economy, and reliability would really suck.

[MKEELINE]

There's a few 24 Spectra's that run alot better then that. Parnelli's old boat ran in the 90's with a 1000 HP if memory serves correctly.
RD
I've seen a 24 Spectra running 2 BBC with v drives. I think it used to run pretty good.

[NWSDan]

what kind of drives are on the "bat boat" in the latest Hot Boat mag? they look like what Morg was talkin'bout.

[jh4rt]

There's a few 24 Spectra's that run alot better then that. Parnelli's old boat ran in the 90's with a 1000 HP if memory serves correctly.
RD
HEHE... He says. Dood, Parnelli told my dad's partner one time (who had the same engine as we had in the spectra, only with a 18' Sanger) that he went over 100 in the 24.
Later 70's Spectras were layed up lighter; ours weighed 9000# on the trailer. Some of the 79's with an outdrive and 1000 hp might have gone into the 90's.
We went the other way on the next spectra, bought a bare hull from Sanger Jack and rigged it with twin 200hp merc's on brackets. That boat goes 70 all the time and rarely breaks.

[jh4rt]

One thing you don't want to do is run twin outboards on a 27-30' boat. The performance, fuel economy, and reliability would really suck.
Yeah! That would suck! Plus, you wouldn't be able to lift the engine hatches and have anything to work on. :devil:
http://www.spectramarine.com/ownersboats/5a.jpg

[Michael2000]

what kind of drives are on the "bat boat" in the latest Hot Boat mag? they look like what Morg was talkin'bout.
The Bat Boat (Vector) I believe just has a standard outdrive. The DCB F26 in that issue on the other hand has a Mercury #6 surface drive, which in many respects looks like an standard outdrive, but isn't.
Michael

[Warp Factor]

Don't see why twins would necessarily need to be counter rotating.
The V-drives, propshafts and props could be offset to the right side of the boat to correct thrust, torque and lift. The right amount should allow the boat to run with a completely straight rudder.