So, I'm trying to determine if my pistons have collapsed or not. So, they clearly haven't collapsed, because they are bigger around the skirt than at the top, but I am confused. I have 3 measurements on each piston. The first line is a measurement perpendicular to the piston pin, just below the oil ring. The second line measurement was taken along the piston pin, just below the hole for the pin. The third line was taken perpendicular to the pin, across the bottom of the skirt. All the measurement are in inches, by the way.
#1 #2 #3 #4
3.7710 3.7700 3.7715 3.7710
3.7568 3.7555 3.7553 3.7570
3.7750 3.7770 3.7770 3.7760
Here's my problem. Tom Wilson's book says that the difference from the top to bottom should be about .0005 inches. Mine seem to be .005. Is this a typo in the book or what? As far as I understand, the only way pistons collapse is they expand when they overheat, then contract too far when they cool. They can't stay expanded, right? What's going on here? Any help is appreciated.
Alan