Piston Fitting
The pistons are "select fit" to achieve proper oil clearance. Engine block cylinder bore diameter grade markings (1) are stamped into the left side of the engine block. These marks are read from left to right, corresponding with cylinder number 1, 2, 3, 4 and represent specific cylinder bore diameters. Refer to SPECIFICATIONS .
The piston is marked with the piston size (1) on the piston crown. The pistons are available in two 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.
The chart below identifies the two piston sizes.
| Piston Marking | Piston Size mm (in.) | |
|---|---|---|
| Metric | Standard | |
| A | 83.950 - 83.960 mm | 3.3051 - 3.3055 in. |
| B | 83.960 - 83.970 mm | 3.3055 - 3.3059 in. |
Typical coated piston shown in illustration.
A 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.