Technical Paper
Engine Lubrication with Different Bearing Metals; Especially, Copper-Lead Alloys
1934-01-01
340119
WITH the advent of light motor-oils, S.A.E. 10-W and S.A.E. 20-W and the introduction of copper-lead bearings in passenger-car and motor-truck engines, new lubrication-factors have arisen with respect to motor-oil stability as well as with respect to the nature of compounds used for the breaking-in period. This paper describes a series of tests which were run using S.A.E. No. 11 babbitt bearings and lead-copper and leaded bronze bearings. The relative extreme-pressure characteristics of the various motor-oils, both mineral and compounded, were recorded. In addition, the coefficients of friction were plotted as ordinates (ƒ) and the viscosity, angular speed and pressure (ZN/P) as abscissas were correlated. For this phase of the work, test apparatus had to be developed. The effect of the mineral and compounded motor-oils on the bearing metals and the causes of deterioration, and vice versa, and the effect of the bearing metals on the stability of the motor oils were checked.