Pistons and Cylinder Bore, Checking

Pistons and Cylinder Bore, Checking

Pistons, Checking





- With an external micrometer 75... Take measurement at 100 mm approximately 15 mm from lower edge of piston skirt and offset 90° to piston axis.

• Deviation from nominal size: Maximum 0.04 mm.






Piston Ring Gap, Checking





- Push piston ring squarely from above down to approximately 15 mm from bottom end of cylinder. To do this use a piston without rings.

- Measure with feeler gauge.






Piston Ring Groove Clearance, Checking





- Clean piston ring groove.

- Measure with feeler gauge.






Cylinder Bore, Checking





Special tools, testers and auxiliary items required

• Inside Micrometer Set 18-100 mm (US1033/S) or Internal Dial Gauge (VAS 6078)

• A shadow or a shiny spot on the wall of the cylinder does not mean the cylinder bore is damaged as long as the cross-grinding is still visible.

• Always measure the cylinder bore in 3 places laterally and longitudinally using cylinder gauge (VAS 6078).

Do not bore, hone, grind or rework the cylinder bores with shop tools. Reworking damages the surface of the cylinder bore.

- Using a (VAS 6078) measure in a diagonal sequence at 3 positions transversely - A - and longitudinally - B -.

• Deviation from nominal size: Maximum 0.08 mm.






• Measurement of cylinder bore may not be performed when the cylinder block is mounted in engine and transmission holder (VAS 6095) , false measurements are possible.