since pistons are tapered slightly, when measuring piston-to-cylinder wall clearance, do you measure from the base of the skirt or what?

 

i use a long feeler gage full heigth of the piston.

 

Measurements are taken 90 degrees from the wrist pin.

 

Most of them will speicfy where you're supposed to measure.... so many thousandths below the ring landsor the top. Without the specific spec that the mfr uses for their pistons, it's mostly just a guess. But most of them are measured at something like ¼ - ½" below the ring lands, and perpendicular to the pin as mentioned.

 

This is where KB says to measure their pistons.


I always measure all around the piston with a micrometer and find the biggest point, then set up a dial bore gage to check the cylinder size. Thats the correct way to do it, but not everyone has the tools or skills to do it that way.

 

ok i found the info from probe industries. right on dart, thats exactly where probe says to measure, and yes, at 90 degrees perpendicular to pin.