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).
Endurance tests on valve springs for the 20/25 HP engine, concluding they are unsuitable for standardisation.
| Identifier | ExFiles\Box 106\5\ scan0064 | |
| Date | 5th July 1932 | |
| Ey. from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. MX.{John H Maddocks - Chief Proving Officer} c. E.{Mr Elliott - Chief Engineer} x5060. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/ADL 5.7.32. VALVE SPRINGS 20/25 H.P. It will be remembered that when we were struggling with gear rattles we found that Valve springs Hs.{Lord Ernest Hives - Chair}477 (E.58525) were a definite benefit in this respect. We have since been running them on endurance tests and finding out their suitability in other ways. We have discovered that they reduce the bouncing speed of the valves by 100 R.P.M. and for this reason we do not think it is desirable to standardise them. This is particularly so in view of the fact that Sales are at present complaining of the high speed performance of the 25 HP. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||