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).
Engine bearing performance, the development of Kelmet bearings, and the decision to retain the current forged connecting rod design.
| Identifier | ExFiles\Box 179b\2\ img089 | |
| Date | 11th November 1932 | |
| -3- EE.1/AL.11.11.32. Cont'd.{John DeLooze - Company Secretary} The intention is that we shall run the two-piece block under the most strenuous overload conditions in order to prove it out. We have tested it under evaporatively cooled conditions and find it very satisfactory. The next item on the engine which we are running near the limit are bearings. Bearings are the feature on the engine which causes anxiety on Type Tests. On the other hand, engines in service have given no trouble as regards bearings. We have already run two Type Tests with Kelmet or Lead Bronze journal bearings. These have gone through very satisfactorily. We have also got several hundred hours experience with these bearings on development engines. We have never yet had a case of a failure of one of these bearings. Fortunately, thanks to Mr. Coverley, we are now able to produce better Kelmet bearings than we can buy anywhere. We are also able to make a perfect Kelmet bearing for the present forged connecting rod. That is we can Kelmet the block inside and out. We have in the past attempted to get such bearings from U.S.A. and they failed to be able to supply and eventually told us it could not be done. We are therefore in a position to be able to fit Kelmet bearings throughout on our present engine. We are certain that these bearings are going to reduce our bearing troubles to a very marked degree. Now that we can provide a complete Kelmet bearing for the present forged rod one of the chief reasons for the articulated rod, which was to enable us to use Kelmet bearings, no longer exists. We consider that we should not be in a great hurry to change from the present design of rod. We have built up thousands of hours of experience on the test beds, thousands of hours in the air, and on the whole we have had very little trouble. | ||