Cylinder Bore Inspection

Cylinder Bore Inspection






1. Measure cylinder liner bore wear and ovality in two axis 40 to 50 mm from top of bore.
Cylinder liner bore:
Grade "A" piston: 94.000 to 94.015 mm
Grade "B" piston: 94.016 to 94.030 mm
Maximum ovality: 0.013 mm
^ Cylinder liners having grade "A" pistons installed may be honed to accept grade "B" pistons provided specified wear and ovality limits are maintained.
^ Worn cylinder liners installed with grade B pistons must be rebored and 2nd-rebore oversize pistons and rings installed.
Second oversize-rebore piston: 94.478 to 94.493 mm
Cylinder liner rebore size: 94.508 mm
2. If piston to cylinder liner bore clearance exceeds following dimension, cylinder liners must be rebored and honed and the 2nd rebore oversize pistons and rings installed.
Piston to cylinder bore clearance: 0.030 mm

CAUTION: The temperature of piston and cylinder block must be the same to ensure accurate measurement. When rebating cylinder block, the crankshaft main bearing caps must be installed and bolts tightened to correct torque.

3. If only new piston rings are to be installed, break cylinder bore glazing using a fine grit, to produce a 60° cross-hatch finish. Ensure all traces of grit are removed after above operation.
4. Check alignment of connecting rods.