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 and horsepower curve data.
| Identifier | ExFiles\Box 72\4\ scan0043 | |
| Date | 4th October 1923 | |
| R.R. 403A (40 H) (SL 42 12-7-23). J.H.,D.{John DeLooze - Company Secretary} -3- EXPERIMENTAL REPORT Expl. No. 9770 REF: HSS/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} | ||