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).
Investigation into the failure of an AC.9 main bearing in a four-cylinder petrol engine during a visit to Dennis Bros. at Guildford.
| Identifier | ExFiles\Box 116\1\ scan0050 | |
| Date | 18th July 1938 | |
| 1020a To Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}16/MH.{M. Huckerby}18.7.38. VISIT TO MESSRS. DENNIS BROS. AT GUILDFORD. Purpose. To investigate failure of AC.9 main bearing in the 100 x 120 four cyl. petrol engine. Procedure. The bearing in question is the centre main of a three bearing crankshaft (unbalanced) and is the only bearing in the engine made of R.R. material. The reason for the presence of AC.9 in this engine is because of trouble experienced with other materials to supply a satisfactory centre main bearing. Also present at this meeting was one representative from the two following firms, Messrs. Wellworthy and Messrs. High Duty Alloys. With reference to the test under which the bearing failed:- Trouble was experienced during the initial run-in period of the bearing tightening up. A new one was fitted and given extra clearance. This one failed at the commencement of a full power run at 3000 r.p.m. The bearing rod picked up badly, and the surface metal had been wiped over the bevel at each end, both from journal and thrust faces. The total bearing pressure at 3,000 r.p.m. was 2100 lbs/sq.in., a figure which we do not consider to be excessive. | ||