Matching of pistons: Notes
IMPORTANT:
Pistons of different makes must not be used in the same engine. The name of the manufacturer is cast inside the piston.
Pistons are stocked as a spare part in standard and oversize dimensions. When oversized pistons are used, the cylinder bore must be rebored to obtain the correct piston clearance.
When matching pistons to cylinder bores, use a 1/2" feeler gauge. When measuring the cylinder bore it should be lightly oiled and the piston, without rings, placed into the bore where it is to work. Attach the feeler gauge to a spring balance and insert it between the piston and the cylinder bore at right-angles to the gudgeon pin. At a tractive force of 8-12 N (1.8-2.7 lbf), the mean clearance equals the thickness of the feeler gauge. Repeat the test with the piston at several different depths.
For piston clearances, see PISTONS .