Cam and Follower Performance Prediction of Lubricants in a Test Rig

The paper describes methods of using the CEC cam and follower rig to predict lubricant performance in hydraulic lifter, finger follower and bucket follower valve train mechanisms, of differing metallurgies. The background situation to the subject in North America and in Europe is referred to, and the authors briefly discuss the relative merits of engine and rig testing of lubricants with regard to this performance aspect. The test rig is briefly described and appropriate literature references are made for greater detail.

Steady condition step load testing has been the essence of 20 hour tests to predict anti-wear performance of lubricants on the basis of highest non-fail loads, and this has been applied to hydraulic lifters and to finger followers. Pitting performance has been evaluated in a different metallurgy using a 50 hour test at a single set of overload conditions.

Results indicate an ability to discriminate between reference oils of known anti-wear performance in field testing. A conventional alkyl zinc dithiophosphate (zdp) SE type blend and low phosphorus SE level experimental blends both favourably compare with the reference oils. Adequate to good performances in pitting tests with the two types of blend are also encouraging.