Thread: Cam Ident.

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You will need a degree wheel and a dial indicator to check duration. Usually you can get a pretty good idea of the duration if you know the lift. They go, somewhat, hand in hand.

You will need a thin head gasket to get decent compression ratio. I believe a flat top piston with 64cc head is around the low side of 10-1 so go from there. I think the Keith Black site has a compression ratio calculator www.k-bsilvolite.com


The welding in the counterweight holes and the rod caps being ground are indicators that the engine was balanced.

MOST forged aluminum pistons look very smooth on the underside. No lines or waffling marks. The area around the pin tends to be solid all the way up to the underside of the piston top. On the outside of the piston, a forging will not have any cast in type numbers or mold marks. Usually smooth on both sides of the pin in the skirt area. No cast numbers or patterns.

Tho the modern pistons are made similar and a novice would have a hard time identifying them from a forging.