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Matching of pistons

Matching of pistons



Important

Pistons of different makes must not be used in the same engine. The name of the manufacturer is cast-in on the inside of the piston.


Pistons are stocked as a spare part in standard and oversizes. The cylinder must be rebored when fitting oversize pistons to obtain the correct piston clearance.

When matching pistons to cylinders, a 1/2" wide feeler gauge is used. The cylinder bore must be lightly oiled and the piston fitted in the relevant cylinder without rings. The feeler gauge should be connected to a spring balance and placed between the piston and the cylinder barrel at right angles to the gudgeon pin. When the load is 8-12 N (1.8-2.7 lbf), then the mean clearance corresponds to the thickness of the feeler gauge. Tests should be carried out at several levels.

Concerning piston clearance, see "Technical data".