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).
Production issues with Bentley main bearings and recommending a change in bearing material.
| Identifier | ExFiles\Box 115\3\ scan0102 | |
| Date | 16th November 1937 | |
| Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}2/JH.16.11.37. BENTLEY MAIN BEARINGS. In view of the production trouble with regard to the picking up andconsequent seizing of the Hall's A.C.2. main bearings and the decision to revert back to the A.C.7. alloy we would make the following recommendation that, the rear main bearing be in W/M.{Mr Moon / Mr Moore} as standard 30 H.P. and the remainder in A.C.7 as decided. The reason for the above is that the A.C.7. is a source of trouble regarding hammering out due to its low Brinnel, this being worst on & developing from the rear main bearing, which causes engine roughness and thump. The combination we suggest has been run 17,000 miles on the Paris trials car B.60.GA. and the actual Whitemetal rear main bearing has covered a total of 27,000 miles on this car. The condition of this bearing as reported in a memo. from Paris is very good and free from cracks, whilst the remaining A.C.7 main bearings with the exception of No.2. have stood up with regard to non hammering out much better than usual, where an A.C.7 main bearing is normally used. Further confirmation of the ability of the rear main bearing in Whitemetal to stand up to the job is shown in the attached photograph of the bearings out of 6.B.IV. after 15,000 miles test in France. These were in Hoyt's Z.3. metal which we have previously proved as having an approximately 10% greater life than our own Whitemetal. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||