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).
Preliminary figures on valve lifts for small and large diameter valves.
| Identifier | ExFiles\Box 151\2\ scan0048 | |
| Date | 27th March 1933 | |
| X235 Hdy. {William Hardy} from Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} 11/KT.27.3.33. We send you herewith some preliminary figures on valve lifts. The tests are not quite what you want because we used the same valve spring for both the small and large diameter valves, whereas we should have used the same ball pin load. The result is that the large valve lifts higher than it would if the ball pin loads had been correctly adjusted. You will notice from the diagrams that the small valve becomes noisy with the short seat, which actually occurs in practice. We think that the large valve looks promising because it is silent and we are continuing our tests with it. Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} | ||