Influence of Lubricant and Material Variables on Cam and Tappet Surface Distress

AN experimental program to determine the influence of crankcase oils on scuffing and pitting of cams and tappets in overhead-valve V-8 engines is described in this paper, which is part of a Symposium on Cam and Tappet Wear.

Results indicate that certain additives may eliminate, while others actually promote, scuffing and pitting of a particular type of surface. At the same time, the protection afforded a tappet surface by any particular additive depends upon the tappet material. An additive that protects steel lifters from scuffing may cause chilled iron tappets to pit. In the authors' tests hardenable cast iron was found to be the easiest tappet metal to lubricate.

Discussion of this and the other papers in the Symposium starts on p. 220.