Need a RH rotation inboard - what are my options?

[parsleap]

Hey boaters,
I am in need of a Right Hand rotation (aka reverse rotation, aka Clock-wise rotation as you look at the flywheel/shaft) inboard engine, for a special project. Need it to be probably a minimum of 250HP perhaps higher. What are my options?

The rotation direction I mention is opposite a standard Mercruiser engine (which are LH), but I have heard of exceptions out there, and want to know what I should be looking for as I scan the various places for such an engine. Looking for something that would have availalbe parts still, vs. customizing a cam or something like that or an engine from a vehicle in the 40's. Let me know your collective thoughts and thanks much!

One caveat - if there is a simple, readily available 1:1 reversing gearbox that might be out there and take the torque and RPMs, and would be more readily available than the engine I'm looking for, that might be of interest too! I just need to get the RH turn somehow.

Thanks!

 

[Don S]

Re: Need a RH rotation inboard - what are my options?

The Borg Warner Velvet drive gear box is reversable. They have been used for years, and still in use today.

 

[parsleap]

Re: Need a RH rotation inboard - what are my options?

Right now the motor is an old 120 flat four cylinder, but that's somewhat irrelevant. I'm wanting to convert over to a dual jet drive system, powered by two yamaha 155mm jet pumps, aluminum intakes, with an inboard motor tucked in between them, belt or chain driving them both. In order to do so, the fly-wheel/shaft will have to face the bow, and I need it to go the opposite direction of what a standard mercruiser goes, in order to turn the pumps the way they're supposed to pump. So, as crazy as it sounds, I'm trying to piece together the budget/concept of such a setup. I need at least 110 hp per and probably more, and they spin about 7000 rpm, so I'll have to have a 1.5 1.75 to 1 ratio to the bigger 4-stroke motor. It's a concept, but I think such a motor is out there... just want to know what to keep an eye out for.

 

[Lyle29464]

Re: Need a RH rotation inboard - what are my options?

You will have little problem finding finding a RH turn marine engine. I see them on ebay and local CL often. The 454s are all over the place But they do not like the RPM you need for a pump.
As stated above most the BW gears will except any input rotation. Most of them come out of the factory with a set output rotation that can not be changed. Hooking up a chain drive would be hard to do. You would need to keep the chain wet. A belt drive would mean you will need to step up the ratio big time. The gear will not except the side load you would need to turn belts. So your looking at a real project hooking the output to your shafts. The shafts will not take a side load.