Rat Bastid said

No sir, I understand exactly what you are saying. I’ll say it again. Valve opening at TDC nothing when it comes to determining valve to piston clearance.

Isky has published those numbers for decades in their catalogue. So has Comp. Most don’t bother because it’s one small number among many that are far more important.

Click to expand...

Bakerlite said

No, you don't understand at all.
Knowing the Valve drop at TDC allows you to calculate what the valve drop would be at say 15 deg BTDC. Then if you know what the valve lift is at 15deg BTDC, then you have your answer.
You can then calculate for every degree of crank angle as long as you know the lift of the cam for that degree.
Pretty simple.

Click to expand...