Tools Required

J 8087 Cylinder Bore Checking Gauge

Important: When fitting pistons, both the piston and the cylinder bore condition must be considered together.

Measurements of all components should be taken with the components at normal room temperature.
For proper piston fit, the engine block cylinder bores must not have excessive wear or taper.
A used piston and pin set may be reinstalled if, after cleaning and inspection, they are within specifications.
1. Measure the cylinder bore taper with the J 8087 .

Maximum Taper
0.10 mm (0.004 in)

2. Measure the cylinder bore out-of-round with the J 8087 .

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




3. Measure the cylinder bore diameter with the J 8087 . Measure at a point 50 mm (1.96 in) and at a point 95 mm (3.74 in) from the top of the cylinder bore.



4. Measure the bore gauge with a micrometer and record the readings.

Maximum Cylinder Bore Diameter
84.050 mm (3.3090 in)




5. Measure the piston diameter with a micrometer at a right angle to the piston pin, 26.5 mm (1.04 in) from the piston skirt.
6. Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance.

Piston-to-Cylinder Bore Clearance
0.02-0.04 mm (0.0008-0.0015 in)

7. If the proper clearance cannot be obtained, select another piston and measure the clearances.
8. If the proper fit cannot be obtained, hone the cylinder bore, rebore and use oversize pistons, or replace the cylinder block. Refer to the Piston Selection Table in Engine Mechanical Specifications .



9. Pistons are stamped with a number 1 or 2. This number represents the outer diameter of the piston. Pistons are available in 2 standard and 2 oversizes.

Standard Size Piston
83.970-83.980 mm (3.3059-3.3062 in)

Standard Size Piston
83.980-83.990 mm (3.3063-3.3066 in)

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

0.50 mm (0.0196 in) Oversize Piston
84.470-84.490 mm (3.3256-3.3263 in)




10. The cylinder block is color coded with either red or blue paint marks (1). This color represents the inner diameter of the cylinder. The piston and cylinder must be matched for correct piston fit.
11. A piston stamped with a number 1 should be installed to a cylinder painted red. A piston stamped with a number 2 should be installed to a cylinder painted blue. Refer to the Piston Selection Table in Engine Mechanical Specifications.

•	A red paint mark represents a cylinder bore diameter of 84.01-84.02 mm (3.3075-3.3078 in).

•	A blue paint mark represents a cylinder bore diameter of 84.00-84.01 mm (3.3071-3.3-074 in).

12. When the piston-to-cylinder bore clearance is within specifications, mark the top of the piston using a permanent marker for installation to the proper cylinder.