Originally Posted by blanks596
Wow, thanks for that great information, but I have one more question. What do you use to measure real head clearance? Also, are stock head clearances standard across brands-ie-are they all .46mm?
Your Welcome.
Use a digital caliper (vernier), and as said before, place piston at TDC and measure distance to lip, then measure head button recess, then subtract and you get head clearance without shims. Now you add shims to get desired real head clearance according to Nitro% to be used.
Yes, that head clearance number is theoretical valid target for all .12 engines, that is why it is best to first measure clearance without shims on every engine, and then add shims to get desired real head clearance.
AFM