Piston And Connecting Rod - Piston Fitting

Piston Fitting





The pistons are "select fit" to achieve proper oil clearance. Engine block cylinder bore diameter grade markings are stamped into the right side of the engine block. These marks are read from front to rear, corresponding with cylinder number 1, 2, 3, 4.

Engine block cylinder bore diameter grade markings correspond to specific cylinder bore diameters. The chart below identifies the three engine block grade markings and their associated cylinder bore diameters.










The piston is marked with the piston size (1) on the piston crown. The pistons are available in three different sizes in order to achieve the desired oil clearance. Select the piston size that corresponds to the engine block cylinder bore diameter grade markings for each cylinder.

Pistons are available in three sizes. The chart below identifies the three piston sizes.










NOTE: Typical coated piston shown.

The coated pistons are serviced with the piston pin and connecting rod pre-assembled. The coating material (1 and 2) is applied to the piston after the final piston machining process. Piston installation into the cylinder bore requires slightly more pressure than that required for non-coated pistons. The bonded coating on the piston will give the appearance of a line-to-line fit with the cylinder bore.