Cylinder Block Inspection
Distortion of Gasketed Surface
Using straightedge and thickness gauge, check gasketed surface for distortion and, if flatness exceeds its limit, correct It.
Cylinder block flatness
Limit: 0.05 mm (0.0020 in.)
Honing or Reboring Cylinders
1) When any cylinder needs reboring, all other cylinders must also be rebored at the same time.
2) Select oversized piston according to amount of cylinder wear.
Oversize piston specification
Oversize 0.50: 78.453 – 78.468 mm (3.0887 – 3.0893 in.)
3) Using micrometer, measure piston diameter.
Measurement position for piston diameter
“a”: 19.5 mm (0.77 in.)
4) Calculate cylinder bore diameter to be rebored as follows.
D = A + B – C
D: Cylinder bore diameter to be rebored.
A: Piston diameter as measured.
B: Piston clearance = 0.02 – 0.04 mm (0.0008 – 0.0016 in.)
C: Allowance for honing = 0.02 mm (0.0008 in.)
5) Rebore and hone cylinder to calculated dimension.
Before reboring, install all main bearing caps in place and tighten to specification to avoid distortion of bearing bores.
6) Measure piston clearance after honing.