What is the critical point of crank rotation for checking valve to piston clearance?
The critical point for both valves is the “Overlap Period” as the exhaust cycle is ending and the intake cycle is beginning. You must start checking the clearance before and continue after T.D.C. on both the intake and exhaust valves to be sure you have the correct readings through the overlap period. You can find all the tools required for checking valve to piston clearance (as well as degreeing a cam) in Crane Cams’ Tune-A-Cam Kit, part number 99030-1.
