Piston: Testing and Inspection

Block and Piston Inspection

1. Remove the crankshaft and the pistons. Crankshaft and Piston Removal

2. Check the piston for distortion or cracks.

3. Measure the piston skirt diameter at a point 14 mm (0.55 in) from the bottom of the skirt.



















4. Measure the wear and taper Y at three levels inside each cylinder as shown. If the measurements in any cylinder are beyond the Oversize Bore Service Limit, replace the engine block. If the engine block is being rebored, refer to step 7 after reboring.

















5. Scored or scratched cylinder bores must be honed.






6. Check the top of the engine block for warpage. Measure along the edges, and across the center as shown.

Engine Block Warpage















7. Calculate the difference between the cylinder bore diameter and the piston diameter. If the clearance is near, or exceeds the service limit, inspect the piston and the engine block for excessive wear.

Piston-to-Cylinder Bore Clearance