Valve to piston clearance

But even if you could see it, how could you measure it? And that is assuming the 'scope was not pushed out or crushed.... the minimum P-V clearance is around TDC.

BTW, Robert.... were you at VA Tech in the late 70's or early 80's, or work at GE in Salem, or were in the US Naval Reserves in Roanoke? If this is your actual name, it suuuure seems miiiiiighty familiar. And did you trade a Celica GT for a Ford Econoline van?