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).
From R. to E.H. continuing a discussion on carburettor design and performance.
| Identifier | Morton\M11\ img154 | |
| Date | 17th March 1919 guessed | |
| To E.H. from R.{Sir Henry Royce} CARBURETTORS CONTD. (3) purposes if a very old one can be found in the stores, and be arranged with a diffuser jet with sufficient hot water and tested on a six-cylinder engine, similar to the "Delage". It is highly desirable in this class of carburettor that the draught of air through the carburettor follows the same law throughout, such as happened with a six-cylinder engine, whether fully open throttle or a closed throttle. Such carburettors cannot be tested on three-cylinder engines and hardly the same with a four-cylinder engine, and it was for this reason that I was so particularly pleased when we found on reconsidering matters that we could run a six-cylinder engine with a single carburettor without serious loss of power at high speeds. In conclusion, one feels that this carburettor question has been so thoroughly worked out and made in every conceivable form that one thinks that a very carefully worked out design using known features should produce perhaps a better carburettor in a given time, than seeking for novel schemes which I have found in my experience have generally had to be abandoned for the best of the known systems. I say this because I fear that a carburettor with a moving diffuser jet, although it may appear simple, might not be so well controlled as one with a larger suction chamber separately, which can be damped in the way we have done in the past. Such a suction chamber can usually be kept in a place where it is free from dust and road grit, and so can be made a close fit to give air damping. R.{Sir Henry Royce} | ||