Tool Required

J 8087 Cylinder Bore Gage

1. Clean the sealing material from the gasket mating surfaces.
2. Boil the engine block in caustic solution.
3. Flush the engine block with clean water or steam.

Caution: Refer to Safety Glasses Caution in the Preface section.

4. Clean the oil passages.
5. Clean the coolant passages.
6. Clean the blind holes.
7. Spray the cylinder bores and the machined surfaces with engine oil.
8. Inspect the threaded holes. Clean the threaded holes with a rifle brush. Refer to Thread Repair .



9. Measure the deck surface for flatness using a straight edge and a feeler gage. Carefully machine minor irregularities. Replace the block if warpage exceeds 0.06 mm (0.0024 in).
10. Inspect the lower crankcase rail for nicks. Inspect the front cover attaching area for nicks. Use a flat mill file to remove any nicks.
11. Inspect the cylinder block for any cracks.
12. Visually inspect the cylinder bores for excessive wear or excessive ridging.



13. Measure the cylinder bore taper, out-of-round and size using the J 8087 .

Maximum Cylinder Taper
0.10 mm (0.004 in)

Maximum Cylinder Out-of-Round
0.10 mm (0.004 in)

Maximum Cylinder Bore Diameter
84.050 mm (3.3090 in)

14. Measure the pistons. Refer to Piston, Connecting Rod, and Bearing Cleaning and Inspection . Pistons are available in 2 standard and 2 oversizes.

Standard Size Piston Diameter

•	83.970-83.980 mm (3.3059-3.3062 in)

•	83.980-83.990 mm (3.3063-3.3067 in)

0.25 mm (0.0098 in) Oversize Piston Diameter
84.220-84.240 mm (3.3157-3.3165 in)

0.50 mm (0.0196 in) Oversize Piston Diameter
84.470-84.490 mm (3.3256-3.32634 in)

15. Subtract the piston diameter from the cylinder bore diameter. The piston-to-cylinder bore clearance should be 0.02-0.04 mm (0.0008-0.0015 in) for each piston in its cylinder.

Important: If the bore is worn beyond the limits, rebore all 6 cylinders and fit with oversized pistons. Select the smallest available oversize piston.

16. Leave sufficient material to allow honing when fitting the piston.
17. Calculate the cylinder bore diameter to be rebored. D = A+B-C when:

•	D = the cylinder bore diameter to be rebored

•	A = the measured piston diameter

•	B = the piston clearance: 0.02-0.04 mm (0.0008-0.0015 in)

•	C = the allowance for honing: 0.02 mm (0.0008 in)

18. Install the lower crankcase and torque to specifications before boring or honing. This will avoid distortion of the cylinder block.
19. Bore and hone the cylinders to the calculated dimension.
20. Measure the piston clearance after the honing is completed.