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).
Engine modifications related to carburetter position and induction system heating.
| Identifier | ExFiles\Box 38\2\ Scan151 | |
| Date | 8th June 1921 | |
| Contd. -2- R10/G8.6.21. I do not think you or we are sufficiently sure of our conclusions of modifications that should be made for me to give final instructions, but below is given my views of the situation to this date. Short of a complete new design of engine we find there are possibilities of getting better results with the carburetter in the present position, and we are also experimenting with the carburetter moved to the exhaust side, but we find this for many reasons, numerous and obvious, very undesirable, and unless we cannot obtain satisfaction without, we shall not recommend changing the carburetter position. It has been proved by Mr. Hives at Derby, that the exact contour of the induction system has a marked effect, so much so that the influence of the internal pipe in the manifold arranged by Springfield was. due to the changing of shape and not due to the heat, and was quite inconsistent heated or unheated. It has for many years been known that the throttle or induction pipe as near the carburetter as possible is the real place to apply heat. This has been confirmed and proved lately to be the only place where it is really effective. The recent lowering of the quality of the fuel has rendered a greater amount of heat necessary, and a sufficiently high temperature with really good gasoline seems only obtainable by use of exhaust, and we give the best scheme we have found. | ||