Scuffs on Piston Skirt

Charrlie_S said

I respectfully disagree. I would reccommend measuring and milling to get a total CR of 8.5-9.0. The actual amount would depend on usage, and cam used. Milling a total of .100 could get the CR up in the range, where the timing curve will get super critical to stay out of detonation, and premium fuel would be required.

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Agreed, for a streeter or truck doing hauling. We used to take upto 100 thou give or take off a virgin head after I'd ported them & tickled chambers for the circuit.dirt rack racing getting comp right up there around 10:1, depending on head gasket. A total of
060" total cut (with some hardened exh seats & Kline bronze guides for early head,) generally raised the Comp Ratio 1 full point approx & kept you out of detonation & still allowed reasonably quick altered advance curve.
Good point. ( although for the racers for the pre-smog heads there's a ton of meat in those heads for serious miling)
Cheers again.T