Cylinder Block Assembly: Service and Repair

CYLINDER BORING
1. Oversize pistons to be used should be determined on the basis of the largest bore cylinder. Piston size identification
Size and identification mark
0.50 O.S. is stamped 0.50
1.00 O.S. is stamped 1.00

NOTE: Size mark is stamped on piston top.

2. Measure outside diameter of piston to be used. Measure it in thrust direction as shown.
3. Based on measured piston O.D. calculate boring finish dimension. The boring finish dimension = Piston O.D. + (clearance between piston O.D. and cylinder) - 0.02 mm (.0008 inch) (honing margin).
4. Bore all cylinders to calculated boring finish dimension.

CAUTION: To prevent distortion that may result from temperature rise during honing, bore cylinders, working from No. 2 to No. 4 to No. 1 to No. 3.

5. Hone to final finish dimension (piston O.D. + clearance between piston O.D. and cylinder).
6. Check clearance between piston and cylinder. It should be 0.02 - 0.04 mm (0.0008 - 0.0016 inch).

NOTE: When boring cylinders, finish all of four cylinders to same oversize. Do not bore only one cylinder to an oversize.