[Steve C.]

Asked previously here on PY within another thread:

"What is the seat pressure and installed height for the old faithful roller cam"

Answer posted by Dave Bisschop:

"To the OP, in most applications we use the Crane 99893 valve spring, installed at 1.790-1.810", I set the intakes on the tighter side of the tolerance, I test all the springs and always put the ones with the higher pressures on the intake valves, since the intake valves weigh more and also have the momentum of the charge pushing on the back side of the valve while the exhaust valve if anything has pressure pushing or drawing it closed and the valve is lighter. On my digital InterComp spring tester the seat pressures on a new set of springs will range from 147-157lbs typically @ 1.800" and 380-390lbs @ 1.200" open pressure."

Side note, regarding pushrod length. To be accurate you should measure and then order. Also, and important, the mention of the Crane 99893 valve spring is for conversation here, and not a recommendation by me. Personally I'd choose something else. And always remember valve springs typically lose some pressure after run in and over time.


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