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 test and examination of AC7 Centricast Bearings, detailing issues and suggesting a new engine build.
| Identifier | ExFiles\Box 115\3\ scan0130 | |
| Date | 25th November 1937 | |
| ① 1020 Rm.{William Robotham - Chief Engineer} eHl. eRHC. eBY. eRm/GwdT. CHPS. Hs{Lord Ernest Hives - Chair}/JWW.1/HM.{Capt. W. Hallam - Head Repairs} 25. 11. 37. Test of AC7 Centricast Bearings. --------- We have been informed by Rm.{William Robotham - Chief Engineer} that the above Bearings have proved satisfactory upon test. Upon examination we find that:- (a) Connecting Rod Bearings have been machined from Castings with insufficient material allowed on the inside diameter. This diameter varies and castings are in the possession of HPS{Horace Percy Smith - Experimental Factory Mgr} which should allow for 1/8" material to be removed. (b) The main bearings with the exception of the centre bearings are fairly satisfactory but show a very bright finish. (c) The centre main bearings show a peculiar deformation in the oilway of the bearing as though the metal had melted. We suggest that a fresh engine be built with:- (1) Connecting Rod Bearings machined as above. (2) Normal main bearings as previously tested. (3) Thermal couple be attached to the centre main bearings to determine the maximum temperature reached under running conditions. In the meantime Hl is examining these bearings and we shall be pleased to know whether any radical changes have taken place in the constituents and construction of the centre main bearing. No definite information exists to the effect that the hard bright finish observed on these bearings is detrimental and we should like to know if this is to be regarded as a sign of seizure, etc. | ||