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).
Bearing fatigue issues in the 4¼-litre Bentley engine and the testing of alternative alloys.
| Identifier | ExFiles\Box 115\5\ scan0236 | |
| Date | 23th January 1939 guessed | |
| ② or induction system, and it was not until the original con- sumption was reproduced by driving on the hand brake only that it was realised that the engine was being made to work harder due to the fact that the foot could be held longer on the accelerator pedal when approaching a corner. It will be appreciated that the road-worthiness of the chassis enables the customer to be very severe on the power unit of a Bentley car. With the introduction of the 4¼-litre, it was found that the white metal bearing which had given such admirable service for more than 20 years was no longer able to perform the duty required of it. The trouble experienced was due to fatigue, i.e, after 30 or 40,000 hard miles of driving, the bearing would gradually crack up, and ultimate- ly disintegrate. In order to enable the 4¼-litre Bentley to be produced, some radical departure from standard bearing practice had to be made. The majority of available alloys on the market, including lead bronze, cadmium tin, cadmium nickel and various varieties of improved babbit were tried out, but none was found to be altogether desirable for the range of conditions under which the average car operates to-day. One big trouble with many of the modern high load carrying bearing alloys is that they are likely to suffer from corrosion. | ||