On stock 302 pistons, whats is max lift? Thinking of Stg 1 cam with 1.72 rockers. Lift would be about 536 I and 550 E. Fit without valves and pistons trying to mate?
You need to check, the deck height and cc of the cylinder head is differant on every motor. That cam should work fine however w/ a 1.6 rocker. (Still would check)
Total valve lift has nothing to do with the possibility of pistons hitting the valves. If they clear with 1.6 rockers, 95% of the times they will clear with 1.7 or 1.72 rockers. It's the overlap period (exhaust to intake cycles changeover) when both valves are partially open at the same that PtV can occur.... like the sample shown below.
Thanks for the answers. I understand the theory but also understand how it can happen. Higher lift can mean faster ramp up, aka, more open at a given point in the cycle which could mean ptv problem. Thanks again for both answers!