PCV issue

fishy68 said

Are you running aluminum heads? If so that's why. Aluminum grows more than iron so aluminum headed engines need less cold lash. I haven't verified that but it's what Bullet cams told me. I have checked my iron headed solid cammed 408 both hot and cold and it tightens up when it warms up.

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Yep. Lash gets tighter when the engine gets hot. The lash changes the lift slightly. Correct me if I'm wrong but the lift should be effected by multiplying the difference in lash by 1.5 (rocker ratio) Just say instead of .020 lash you set it at .015 (.005 x 1.5 = .0075) You would increase the lift of your .450 lift cam to .4575. Not a lot but it could make a slight difference in the way it runs. The most important thing about valve lash is keeping a clearance between the valve stem and the rocker tip when the engine is at operating temp. If the valves are set too tight, they stay open and especially the exhaust valves can get hot enough to burn if they don't close to the seat. tmm