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).
Vibration issue, including a table of horsepower versus revolutions.
| Identifier | WestWitteringFiles\K\October1923\ Scan28 | |
| Date | 4th October 1923 | |
| R.R. 493A (40 H) (SL 12 12-7-23). J.H., D.{John DeLooze - Company Secretary} -3- EXPERIMENTAL REPORT. Exptl. No. 9770 REF: Hs{Lord Ernest Hives - Chair}3/LG4.10.23. we appear to get a vibration which appears to be similar in character to the high speed vibration on G.11. This is only our impression - it may be due to valves leaving their seats - this we are checking. The best HP. curve with Claudel carburetter, std. induction pipe and hot spot is as follows :- Revs. | HP. ----------------- 500 | 30.1 750 | 45.0 1000 | 60.5 1250 | 75.5 1500 | 90.0 1750 | 103.5 2000 | 110.4 2250 | 120.0 2500 | 121.6 Hs.{Lord Ernest Hives - Chair} | ||