Grab the piston with the lathe in a 3-jaw chuck in the area where the rings are installed, and roll the skirt past the knurling tool by hand, slowly increasing pressure on the cross feed to put three pretty deep knurl patterns about 1/2" apart which cover most of the area near the wrist pin- - -one knurl above the pin, another at pin level, and the last one below the pin. Do this on both skirts, and use a micrometer to measure your progress. It's really a pretty simple procedure, and you can increase the diameter of the skirt by 3 or 4 thousandths pretty easily. Perfect Circle uased to sell a bench top tool called a "Nurlizer" to shops without a lathe. The knurling wheels were made to put a stylized "P-C" pattern on the piston skirts.
Jerry
