Carburetter design improvements, focusing on constant vacuum, diffuser jets, and various existing models.
| Identifier | ExFiles\Box 39\2\ Scan255 | |
| Date | 11th March 1909 | |
| -2- contd. work being very exacting, apparently because one has to follow the grades in the road and the varying speed depending upon the road dangers. I have sent Mr. Southern a sketch of a carburetter arrangement which may turn out useful, and which apparently can begin at the smallest dimensions, and yet give ample area, maintaining a constant vacuum. With a constant vacuum carburetter, it is necessary to vary the size of the petrol passage, as well as that of the air passage, and I think we ought to test all of the carburetters that have been made on these lines. For a long time I have thought that the missing feature of this type of carburetter is the diffuser jet, which you will see is applied in the system suggested. Combining the idea of the diffuser jet and sufficient heat in the induction pipes, carburetter throttle, etc., and possibly warm air to the carburetter would, one thinks, enable us to make a carburetter which will beat our existing one. (Will be very difficult; when sufficiently heated, the engine runs wonderfully well). These carburetters, such as our own present standard and the Smiths multi-jet, always stand at a disadvantage when an additional jet is cut in. It is for this reason that the carburetter should be of the expanding type, as originally fitted to our own two-cylinder cars, which has appeared in various patterns, namely, Brotherhood, Bradley, Polyrhoe, S.U., Stewart's Precision etc. Cont | ||
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).