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).
The development, material composition, and comparative testing of light alloy engine bearings.
| Identifier | ExFiles\Box 115\5\ scan0219 | |
| Date | 6th December 1938 guessed | |
| 8 hard constituents of widely differing hardness values forming a mosaic pattern which will not be torn out during machining nor yet pierce the oil film under conditions of poor lubrication. It was also discovered that correct additions had to be made to the solid solution matrix to produce an optimum hardness value to prevent seizure on soft shafts. After exhaustive road tests these bearings were fitted as standard components on the big-end and main bearings of the [strikethrough]SHARP. Rolls-Royce[/strikethrough] [handwritten]PIII & 25/30 big ends[/handwritten] engines and also now on the Bentley engines; and are now the only cast light alloy bearing successfully applied as a standard component. The following tests were made on a Rolls-Royce "Kestrel" aero engine centre main bearing, and demonstrate the super- iority of the Aluminium base bearing over White Metal and Lead Bronze. A Nickel-Chromium crankshaft, 3.5 per cent Ni. 0.7 per cent Cr.{Mr Cra???ster / Mr Chichester} was used, quenched in oil from 820°C. and tempered to a Brinell hardness of 302 at 600°C. The White Metal was a standard composition 87.3 per cent Tin, 9.4 per cent Antimony, 3.2 per cent copper, 0.1 per cent lead; the Lead bronze being 70 per cent copper, 28 per cent lead, with traces of tin, etc. The light alloy bearing was 90 per cent aluminium, the remainder being carefully con- | ||