Cylinder Block Assembly: Testing and 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 16.0 mm (0.630 in) from the bottom of the skirt.

J35Z6 engine





Oversize Piston Skirt Diameter





J37A4 engine









4. Measure the wear and taper in direction X and Y at three levels in each cylinder as shown.

5. J35Z6 engine: If the 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 8 after reboring.

J37A4 engine: If the measurements in any cylinder are beyond the service limit, replace the engine block. The J37A4 engine block can not be rebored.

J35Z6 engine





Oversize










Bore Taper





J37A4 engine





Bore Taper










6. J35Z6 engine: Hone any scored or scratched cylinder bores.

NOTE: The J37A4 engine can not be honed. If the cylinders are damaged, the engine block must be replaced.

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

Engine Block Warpage










8. 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 cylinder bore for excessive wear.

J35Z6 engine





J37A4 engine