marine block 427- reverse rotation?

[diiulio]

I was wondering how one can determine if a marine engine is std or reverse rotation? I realize that it oils reverse, but how can you tell that it is reverse?
Jason

[Ibr8k4vetts]

I think the only thing that makes it a reverse rotation is the cam and the back of the crank might have a channel cut in it to draw the oil away from the rear main seal, but that can be ground out.
Mike

[A Snake]

Only the cam, oil pump and starter really differ. The crank will need to be balanced neutral, just as it would in conventional rotation. The oiling is the same. Remember, it still goes through the same passages. The pump itself, runs in reverse at the shaft, but the design of the pump body flows the oil as normal rotation would. I've heard that some pumps have an extra gear to change the pump gear rotation. Don't know about that for sure.

If using a marine 427, don't make the mistake of not changing the oil pump to conventional. The cam is a given for change as is the starter. Any good auto electric shop can change the polarity of the starter for you. Probably just as cheap to buy a new on though.

Last note; look carefully at the condition of the block and heads. Corrosion can be a big item if the engine was used in salt water without a closed, fresh water cooling system.

Al

[Seaman]

The easiest way from the outside is to look at the intake manifold. The reverse rotation engines had the cast firing order numbers ground off of the intake. This is because they fire in a different order than the standard rotation engine. If still in doubt, pull the distributor. The gear will have an opposite helix to the standard rotation engine.

Dave