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).
Experiments and suggestions for improving petrol economy in car engines.
| Identifier | ExFiles\Box 147\5\ scan0059 | |
| Date | 9th May 1916 | |
| Mr Hives X459 COPY. To Wer. for EH from R.{Sir Henry Royce} c. to J.{Mr Johnson W.M.} R4/DB{Donald Bastow - Suspensions}9516. May 9th 1916. Re Petrol Economy. Regarding the car engines, for petrol economy I have not found any material benefit from stopping off part of the radiator, but the engine runs decidedly better by being kept warmer by this means. I have however, a distinct impression that the extra advance of the magneto from 12° to 15° is a decided advantage in consumption. To improve the consumption I suggest that we arrange for some decidedly higher compression pistons on one engine and on another engine to try a smaller diameter of induction pipe and throttle. I shall be glad if you can at some convenient time, let us know the results obtained from these two suggestions of road consumption. If you wish me to carry out some of the experiments, you can get the parts ready for this 49GB and either change then here or have the car at Derby. I have the decided impression that with this increased advance of the magneto, the car is decidedly faster even with the full strength of mixture, and certainly faster when petrol is being economised. I have not noticed any disadvantages, and intend to increase the magneto slightly more as I have only got it 12° advanced at present. R.{Sir Henry Royce} To enable a weak mixture to be used with comfort and pleasure in driving, I have the impression that a slower moving piston in the carburetter would be a decided advantage can you send me one slower than that in 49GB. which has already the drilled hole stopped up. F.H.R. | ||