Not always. my ship uses a huge gearbox to join the two together, with a single output, but then they are 8000hp motors Here's a couple of pics from my collection: I don't see how you could run twin open diffs, as the centre shaft would just spin crazily and you'd go nowhere. Maybe if one diff was locked solid it would work.
Get on one of the drag boat sites and see if you can get Ed Hill to respond. I think he checks them out at times. He could tell you how he did his side by side Pontiac back in the Sixties. I seem to think it was dual rear end chunkss on a common axle housing. K
MIZ, Why put one forward and one backward? If you connect the cranks directly with a chain or belt both engine need to turn the same direction. Mount them side by side, put the biggest blower drive pully you can on the crank snounts and run a belt around them. Done deal! Rex
Rex, I was thinking that too. Would like to check with some drag guys as to whether the belt would hold up, especially with two motors fighting between each other. lets face it, no two motors are going to be perfectly in synch at all RPM's. A chain would ensure they do. Not quite sure as of yet if the Blower/Gilmer belt would. remember with a blower their is only one driving force, that being the engine. The blower is just along for the ride. But were on the same wave length.
I remember reading about one of Tommy Ivo's twins (Buick I think) where they just meshed the flywheel teeth and ran one motor backwards.Said they had no prob with wear.?? Sounds too simple but who's to say. Ron
Two diffs on a common housing with a spool in one, each driven by a separate drivetrain might be more practical on the street. I think Roth's twin Ford engined car was set up that way.
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