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).
The compromise between engine idle speed and high-speed performance, particularly concerning the Bentley model.
| Identifier | ExFiles\Box 85\4\ scan0095 | |
| Date | 27th October 1934 | |
| -2- Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}4/KW.27.10.34. When cars leave the Works the slow running is set for the engine to idle at between 350 and 400 r.p.m. With this setting the idling is not perfectly even, but the engine will not stop in traffic. If a customer's car will run like this, no adjustment can be expected to make it any better. If an endeavour is made to make the engine tick over more slowly than this, very uneven slow running will result and the engine will stop in traffic. We do not know whether Kingsbury are aware of this or not. Since the Bentley is fifteen miles an hour faster than the 20/25, we think that if customers are told that a certain degree of slow running has been sacrificed to obtain the high speed result, they cannot reasonably complain. Technically, the adoption of the Bentley name allowed us to make this particular compromise in order to appeal to a clientele outside that served by Messrs. Rolls-Royce; at present we see no prospect of getting 120 B.H.P. out of an unsupercharged 3½ litre engine without the idling being open to criticism. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||