Piston: Description and Operation

The pistons are cast aluminum with steel struts using two compression rings and one oil control ring. The piston pin is offset 0.8mm (0.031 inch)towards the major thrust side. This allows a gradual change in thrust pressure against the cylinder wall as the piston travels its path. Pins are chromium steel and have a floating fit in the pistons. They are retained in the connecting rods by a press fit.