Claybar method?

[rx7_guy]

For the clay bar method you lay a strip of modeling clay ~0.20-0.25" thick on the surface of the piston (head off), reinstall head, spin the crank over at least 2 times, remove the head and see how big a dent you made in the clay.

http://bringthepaynes.googlepages.com/CIMG3002Medium.JPG/CIMG3002Medium-full;init:.jpg

Has any one ever done this before?

[Eric@TCGMiami]

Why would you use clay for checking piston to head clearence?

[rx7_guy]

I have no Idea? I was just wondering if this was being done a lot.