Piston: Testing and Inspection
INSPECTION1. Check the piston for distortion or cracks.
NOTE: If cylinder is bored, an oversized piston must be used.
2. Measure piston diameter at a point 17 mm (0.67 inch) from the bottom of the skirt.
NOTE: There are two standard-size pistons (A = no letter and B). The letter is stamped on the top of the piston. These letters are also stamped on the black as cylinder bore sizes.
- Piston A (no letter) Diameter
- Standard (New): 89.986 - 90.004 mm (3.5427 - 3.5435 inch)
- Service Limit: 89.97 mm (3.5421 inch)
- Piston B Diameter
- Standard (New): 89.976 - 89.994 mm (3.5424 - 3.5431 inch)
- Service Limit: 89.96 mm (3.5417 inch)
3. Calculate the difference between cylinder bore diameter and piston diameter.
- Piston-to-Block Clearance
- Standard (New): 0.006 - 0.034 mm (0.0002 - 0.0014 inch)
- Service Limit: 0.0825 mm (0.0032 inch)
- Oversize Piston Diameter
- 0.25: 90.226 - 90.244 mm (3.5522 - 3.5529 inch)
- 0.50: 90.476 - 90.494 mm (3.5620 - 3.5627 inch)