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).
Comparison of the 46-PK model with the final EAC regarding expected improvements in engine performance and refinement.
| Identifier | ExFiles\Box 69\2\ scan0093 | |
| Date | 4th July 1924 | |
| X8770 To Bd.{Mr Berend} from Hs.{Lord Ernest Hives - Chair} S E C R E T. Hs{Lord Ernest Hives - Chair}1/LG4.7.24. <u>E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. ll.</u> <s>GENERAL COMPARISON OF 46-PK AND</s> <s>FINAL EAC. AS WE KNOW IT AT PRESENT.</s> The engine silence on the final cars we expect to be a little better, chiefly because we hope to get the engine to run better slowly. With the engine running at any speed we do not expect the silence will be improved to any extent. There is a certain amount of noise coming from the carburetter which we are trying to reduce. We expect the power of the final car will be 5 to 10% better than 46-PK due to the improved exhaust system and possibly being able to use higher compression when we have the new cylinder head. It is possible, on the final car, that we shall be able to use a lower gear ratio and run the engine faster because there are instructed new Camshafts to allow for this. This will improve the acceleration. <u>SILENCE.</u> There are no alterations in hand which are likely to improve the general silence except that we expect to improve the silence with the engine running idle by getting it to run more evenly at slow speeds. <u>VIBRATION.</u> As regards vibrations when picking up with power on - we do not expect the final car to be an improvement. We may get less vibration on the final car with the throttle closed because of the lighter pistons which are being instructed. <u>DETONATION.</u> The car is fitted with a Magneto with automatic advance but as the engine is comparatively free from carbon, there is very little detonation. contd:- | ||