Cylinder Block Assembly: Service and Repair

1. Oversize pistons to be used should be determined on the basis of the cylinder with the largest bore.
2. Oversize pistons are available in 0.50 mm and 1.00 mm oversize dimensions. Measure the diameter of the piston to be used. Boring must be carried out such that the piston-to-cylinder clearance complies with the standard value. The piston's diameter should be measured at the points shown.
3. Calculate the boring finish dimension based on the piston diameter dimension.
Boring finish dimension = piston O.D. + piston-to-cylinder clearance 0.02 - 0.04 mm (0.0008 - 0.0016 inch) - honing margin 0.02 mm (0.0008 inch).
4. Bore each cylinder to the calculated boring finish dimension.

CAUTION: To prevent distortion caused by heat increased during boring, bore the cylinders in the following order: No. 2, No. 4, No. 1 then No. 3.

5. Hone the cylinders to the final finish dimension (piston O.D. + piston-to-cylinder clearance).
6. Check the clearance between the pistons and cylinders.
Standard value: 0.02 - 0.04 mm (0.0008 - 0.0016 in.)