Measuring pistons?

[flatjack9]

The measurement perpendicular to the pin and about 1/2" above the bottom of the skirt is what is used to determine the bore size for proper clearance. Another very important measure is the width of the ring grooves to be sure they are not too worn.

[Binx]

Originally Posted by flatjack9

The measurement perpendicular to the pin and about 1/2" above the bottom of the skirt is what is used to determine the bore size for proper clearance. Another very important measure is the width of the ring grooves to be sure they are not too worn.

Along with measuring, clean the grooves completely with solvent and a stiff bristle brush. Look at the sides of the grooves closely with a magnifying glass or loupe. If you see a step worn in the groove it won't seat new rings.

Lonnie