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Counter rotating engine

T

Tom Cahoone

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"When installing pistons in a

"When installing pistons in a counter-clockwise engine, what position do the notches in the pistons face, toward the front or rear of block?"
 
"Alright, very good. Thanks. N

"Alright, very good. Thanks. Now is there any difference in a clockwise/counter clockwise engine far as the pistons are concerned?"
 
"The pistons go in the OTHER w

"The pistons go in the OTHER way around in a reverse rotating engine! Put them in the "usual" way and you'll have piston slap like crazy. Hence, the notch goes in facing the rear of the engine.

The pistons are the same (except they go in the other way around), but the crankshaft seals are different. Be careful there or oil will leak on you.

Jeff"
 
"Jeff, I think the crank not t

"Jeff, I think the crank not the seal is different, my parts book shows only 3 different parts for a reverse engine. The crank, the cam and the dist. drive gear.

Dan"
 
"Could be, but the gasket kit

"Could be, but the gasket kit that came with mine had seals for both type engines. I assume (and that's never good!) that the seals themselves are different....

Jeff

PS: It would be nice to know for sure."
 
"Guys,
I just tore down a LM3

"Guys,
I just tore down a LM318 Reverse Rotating engine.
The piston notch was to the front of the engine.
The rear main seal is different on the reverse rotating engine. (They have small rubber tabs on either side. I don't think this engine had ever been torn apart and everything was factory. The crank is the same for marine and auto use - from 1962 to 1993. The cam is different - the drive gear is reversed. NOW here is a killer -- as I was taking mine apart to rebuild, the no 2 MAIN cap was broken. Never seen a main cap break in my life. Rod caps, rod bolts even crankshafts I've seen broke but never a main cap. If anyone has a rebuildable engine block, I would be very interested."
 
"If those notches were aimed a

"If those notches were aimed at the front, then someone had it apart alright. That might also account for the broken main cap; that happens due to insufficient torque on the bolts.

Jeff"
 
Thanks Jeff... We scratched ou

Thanks Jeff... We scratched our heads wondering about the position of the notch. I couldn't tell that the engine had been torn down. It is possible though.
 
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