Block and Piston Inspection
INSPECTION1. Check the piston for distortion or cracks.
2. Measure the piston diameter at a point 16 mm (0.6 inch) from the bottom of the skirt. There are two standard-size pistons (No Letter or A, and B). The letter is stamped on the top of the piston. Letters are also stamped on the block as cylinder bore sizes.
Piston Diameter:
Standard (New):
No Letter (or A): 85.980 - 85.990 mm (3.3850 - 3.3854 inch)
B: 85.970 - 85.980 mm (3.3846 - 3.3850 inch)
Service Limit:
No Letter (or A): 85.970 mm (3.3846 inch)
B: 85.960 mm (3.3842 inch)
3. Measure 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 block. If the block is to be rebored, refer to step 6 after reboring.
Cylinder Bore Size:
Standard (New):
A or I: 86.010 - 86.020 mm (3.3862 - 3.3866 inch)
B or II: 86.000 - 86.010 mm (3.3858 - 3.3862 inch)
Service Limit: 86.070 mm (3.3886 inch)
Oversize: 0.25: 86.250 - 86.260 mm (3.3957 - 3.3960 inch)
Reboring limit: 0.05 mm (0.020 inch) maximum
Bore Taper:
Limit: (Difference between first and third measurement) 0.05 mm (0.002 inch)
4. Scored or scratched cylinder bores must be honed.
5. Check the top of the block for warpage. Measure along the edges and across the center as shown.
Engine Block Warpage:
Standard (New): 0.07 mm (0.003 inch) maximum
Service Limit: 0.10 mm (0.004 inch)
6. 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 cylinder block for excessive wear.
Piston-to-Cylinder Clearance:
Standard (New): 0.020 - 0.040 mm (0.0008 - 0.0016 inch)
Service Limit: 0.05 mm (0.002 inch)
Oversize Piston Diameter: 0.25: 86.230 - 86.240 mm (3.3949 - 3.3953 inch)