when i installed my cam (SOHC NONVTEC) i degreed it in to the cam specs. i had .070 P2V clearance i want to retard the cam 2 degrees to see if my power band shift much. i have no idea what the piston to valve clearance would be. so what i figured
1 put a dial indicator on the top of the piston down the spark plug hole.
2 hold the cam gear and not let it turn with the belt.
3 take note how much the piston moved while the cam gear shifted 2*.
4 subtract the amount from the .070

will this work or is there something i am missing

 

found a video on youtube on how to do it with out clay. it will work on a single cam