Operation CHARM: Car repair manuals for everyone.

Cylinder Block Assembly: Testing and Inspection






Piston and Cylinder Bore, Checking

Pistons, Checking





- Measure approximately 15 mm from the lower edge at a 90° angle to the piston pin axis using a 75 to 100 mm external micrometer.

Maximum deviation from nominal dimension: 0.03 mm.

Matching pistons are allocated to the different manufacturing stages of the cylinder block.






Measuring Cylinder Bore





- Measure in a diagonal sequence at 3 positions transversely - A - and longitudinally - B - using a cylinder gauge (VAS 6078) or inside micrometer set 18-100 mm (US1033/S).

Maximum deviation from nominal dimension: 0.08 mm.






Measuring the Piston Ring Gap





- Push the piston ring squarely from above down to approximately 15 mm from the bottom end of the cylinder.

- Use a piston without a piston ring for sliding in.






Measuring the Ring to Groove Clearance





- Clean the piston ring groove before checking.