better fuel economy as they spin half the rpm of gs engines

You'd lose top end, but get a better cruise.
And reduce your chance of explosions drastically, much safer.
Better range too.
Check these out.
http://www.marinedieselusa.com/marin...e-company.html

you won't lose top end with 3 speed gearboxes...

Sean, you got any spypics of this rig?

Thank you. Don`t mind if I do.

i do but i would have to kill you if i showed you...

Can you put a shift kit in the drives for that extra roost when going up thru the gears?

It would take 6's or Arneson's to be able to achieve the diameter/pitch of prop with that kind of torque at 3k rpms.

The article you are thinking about, Croozin2, was in Powerboat in '04 or '03. It was not South Florida, though. It was St Petersburg and the shop was Mastry Engine Center, the distributor for Yanmar Diesel Engines. The person in charge of the project was Adib Mastry. He put two 440HP Yanmars in a 36 Spectre and achieved 108mph in front of Bravos. What he said the problem was, is the props get too big and don't work properly. He then decided to rig the boat with Arnesons. With the surface drives its likely they will use two speed transmissions from ZF, since Mastry is a ZF distributor.

I wouldn't worry about top end. But, then again, I don't care about the top end. I just want to cruise with MINIMAL MAINTENANCE!

Stormrider, sorry to say but this Marinediesels are just crap.
Its buildt from some spare-engines (AMC-Hummer).
I know it cuz some raceguys in Sweden had major problem with their setup. 10 minutes and then broke down. Now the go with Volvo D6-350 and the great DPR-drive.