IN his discussion of oil cooling and its relation to bearing life the author attempts to answer four questions: (1) Why temperature affects bearing life; (2) What the actual bearing temperatures are in service; (3) What factors cause high oil and bearing temperatures to be generated; and (4) How to reduce these temperatures most conveniently and effectively.
The best method of cooling the oil, he finds, is by the use of radiators in the air blast. Heat exchangers utilizing the engine cooling water, he believes, are not practical for engines where oil temperature control to 180 F maximum is desired. Also, jacketing the oil pan or employing cooling-water coils in the oil pan are not considered feasible methods.
Pointing out that all authorities on automotive lubrication recognize that a lubricating oil temperature of 180 F gives optimum overall engine performance, he concludes that it is possible to maintain the lubricating oil temperature at or below this value in a large automotive diesel engine. In his discussion of oil coolers he brings out their influence on bearing life, on cylinder lubrication, and on effective life of lubricant.