Yep Tech------people seem to be sighted in on tdc at overlap when the piston chasing the exhaust valve and intake valev chasing piston dance step . I like using clay as it will on one setup measure everything -just gotta be careful--I find many engines other people have done that have gobs of v-p but marks where outter valve has touch radius of valve notch, especially with heads with bigger valves where they have been moved


DISCLAIMER-I didn't read all thru this article, just thought it was a very good explaination and lots of good pics------I have pretty well stopped taking pics of my work as its too impossible to post them in a level that the microscopic details are visable