Block And Piston Inspection

Block and Piston Inspection

1. Remove the pistons from the engine block Crankshaft And Piston Removal.

2. Check the pistons for distortion or cracks.

3. Measure the piston skirt diameter at a point 16 mm (0.63 in) from the bottom of the skirt.

Piston Skirt Diameter





Oversize Piston Skirt Diameter










4. Measure the wear and taper in direction X and Y at three levels in each cylinder as shown. If measurements in any cylinder are beyond the oversize bore service limit, replace the engine block. If the engine block has to be rebored, refer to step 7 after reboring.

Cylinder Bore Size





Oversize










Bore Taper










5. Hone any scored or scratched cylinder bores Cylinder Bore Honing.

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 cylinder bore diameter and the piston diameter. If the clearance is near or exceeds the service limit, inspect the piston and the cylinder bore for excessive wear.

Piston-to-Cylinder Bore Clearance