From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter to Wellworthy Piston Rings Ltd. discussing the weaknesses of white metal bearings at high temperatures compared to A.C.9 alloy.
| Identifier | ExFiles\Box 115\5\ scan0227 | |
| Date | 8th December 1938 | |
| 1020a. Rml/R.{Sir Henry Royce} 8th December, 1938. J.{Mr Johnson W.M.} Howlett, Esq., Wellworthy Piston Rings Ltd., LYMINGTON, Hants: Dear Howlett, With reference to your 'Write-up' on aluminium tin bearings, there is one point which you have missed, and this is perhaps white metal's greatest weakness, i.e., elevated temperatures. Generally speaking, we find that if the temperature of the oil going into the bearings exceeds 100°C, then a white-metal big end bearing is going to have a very unhappy time. The main bearings, of course, are in a better position because they can get rid of their heat through conduction to crankcase. We attach photographs which illustrate the condition of a white metal bearing after an over-load test in a Bentley engine, and a picture of some bearings in A.C.9 alloy after running 7 times as long, results which we think are rather conclusive. The test was continued until the Rolls-Royce bearings had completed 250 hours, or 25 times as long as white metal, and the A.C.9 bearings showed no sign whatever of failure. Yours sincerely, | ||