PROBING THE CAUSES OF PISTON-RING WEAR BY THE RADIOTRACER TECHNIQUE

Three successful radiotracer projects are described. The first illustrates the use of a radiotracer technique to find the cause of ring wear occurring during abnormal combustion. Continuous preignition was found to cause extremely high adhesive wear of top piston rings. However, engine knock has no influence upon this adhesive mechanism of wear.

The effect of dispersant oil additives on the adhesive wear of top-ring chrome depends both on their type and their concentration. Iron side wear is also affected by dispersant additives, but to a lesser degree.

The radiotracer technique is also useful in fleet studies.

Without interfering with the major purpose of the program, data on chrome-face wear of top piston rings have been collected in a fleet test designed to provide data on octane-requirement increase and sparkplug fouling.