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 a compromise on bearing alloys and crankshaft hardness.
| Identifier | ExFiles\Box 115\5\ scan0271 | |
| Date | 13th May 1939 | |
| 1020a. Rm{William Robotham - Chief Engineer}5/R.{Sir Henry Royce} 13th May, 1939. J.{Mr Johnson W.M.} Howlett, Esq., Wellworthy Piston Rings Ltd., LYMINGTON, Hants: Dear Howlett, Thank you for your letters. Taub and Constantine visited us yesterday. We went very thoroughly into the R.R. bearing alloy. We explained the way we were using it. Briefly, the compromise we have finally arrived at, is to take advantage of the aluminium tin alloy and reduce our big-end bearing width and use the bearing length so saved on the main bearings. The result in increase in main bearing size has enabled us to continue to use babbit. We showed Taub a strip of an engine which has just finished an endurance run with this combination, which has increased the bearing life of the engine just 300%. We explained the necessity for improved lubrication of the big-end. Also, why we preferred aluminium R.R. bearing alloy to lead bronze. We did not attempt to sell Taub aluminium tin for main bearings, because, in almost every engine we have seen, if advantage is taken of reducing the big-end bearing size, it should always be possible to get away with white metal on main bearings, and if the unit load can be reduced sufficiently to enable white metal to do the job, as far as I know, there is no better material in existence. Taub's crankshafts are very soft, about 260 brinell. We think this is too soft to be fair to the bearing material even on the pins. We recommended that he should toco-harden the pins only, which we believe he could get done for somewhere about 2/- a shaft. | ||