Vauxhall Workshop Service and Repair Manuals

Piston Projection, Check (Cylinder Head Removed

Remove combustion residues from piston head and cylinder head before measuring.

Place magnet holder with gauge on piston head and set gauge to "0".

Turn magnet holder until probe tip of dial gauge rests on sealing surface of cylinder block.

Important

If the piston projection is less than 0.58 mm/0.028 in. or more than 0.78 mm/0.030 in., another assembly of piston and conrod should be chosen.

Measure piston head projection at three points per piston and determine the average of all 12 measurements.

Select cylinder head gasket:

Average piston projection - Cylinder head gasket

0.58 to 0.64 mm          - 1.35 mm A = one notch

0.65 to 0.70 mm          - 1.40 mm B = two notches

0.71 to 0.78 mm          - 1.45 mm C = three notches

If the measurement of the piston projection shows that even one of the total of 12 measured values exceeds the upper limit of the gasket selection range in question by 0.05 mm/0.002 in. or more, then select the next gasket class.