HEAVY-DUTY lubricating oils containing metallo-organic compounds were effective in decreasing, but not totally preventing, piston-ring pinching and sticking in Naval diesel engines, Mr. Klemgard reports, summarizing the results of tests on medium and high-speed two and four-cycle diesel engines of both automotive and heavy submarine types, in which various additive and non-additive type oils were tested.
In general, he continues, one or another of the additive-type lubricating oils was superior to non-additive type oil in piston lacquering, piston-ring sticking, and wear of liners and piston rings in the test engines. The desired objective, he concludes, is a combination of the best diesel engineering designs and heavy-duty lubricating oils of the most universally favorable characteristics.