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).
Increasing the casehardening depth of cams and altering pedal stops to address cam indentation issues.
| Identifier | ExFiles\Box 95\4\ scan0119 | |
| Date | 14th January 1936 | |
| -2- Ha/FJH.{Fred J. Hardy - Chief Dev. Engineer}11/KW.14.1.36. We intend to fit to the next 10,000 mile test car cams with the depth of casehardening increased from the present 0.025-0.030" to 0.050-0.060", and we suggest that this should be done on production as soon as possible. We think that the altered pedal stop could also be standardised when the Design Dept. scheme is issued as the experimental one on 31-AX was satisfactory in principle. The first case of indentation of cams in the "off" position occurred on 5-B-IV. At the time the trouble was thought to be peculiar to the floating type of cam fitted to this car. However, the standard cams fitted to B-56-BN{W.O. Bentley / Mr Barrington} were indented in the same way so we conclude that the cause is the increased relative movement between the gearbox and brake pedal.allowed by the rubber mounting at the rear of the gearbox. This means that the present production Bentley, and, possibly, also the 25 HP., are liable to have this trouble. We intend to fit the altered brake pedal stop on 6-B-IV and 22-C-V.{VIENNA} Hs{Lord Ernest Hives - Chair}/F.J.Hardy. | ||