Piston Replacement

The next time you do engine work, throw away the pistons and install new ones with cam ground .020 or less! Until recently, most replacement pistons were cam ground as much as .040, too much for the “A” that never reaches the 220 degrees of your late model car. This will result in poor compression and blow by.

Normal choking and blow by will dilute the oil rapidly at about the same rate you burn oil; 500 miles per quart. The level on the dipstick remains high and becomes the consistency of cutting oil in 1500 miles. The “A” normally runs too cool to boil off the gasoline.

On new pistons the thrust surfaces are usually about .003 under bore size. They must be trying to tell us something here, but just try to obtain factory spec clearances. The engineers are always out to lunch. I shoot for .002 side clearance, so far so good.

You will be pleased with the increased performance and will, after the break in, have at least 20# more compression than your buddy’s ride.

This tech tip was supplied by Pete Amsler and printed in the June 1997 “A” Quail Call.

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