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).
Single versus twin carburetter setups for the Phantom model, including designs for Japan.
| Identifier | ExFiles\Box 102\1\ scan0021 | |
| Date | 8th July 1931 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} X5080 R4/M8.7.31. (SENT OFF 11.7.31.) X.7080 X.5080 PHANTOM & JAPAN TWIN CARBURETTERS. With reference to the single carburetters we have already sent you for Japan, these could be tested with two separate pipes, or with a through pipe, in which latter case we should expect that the power at high speeds would be very high, but according to HS{Lord Ernest Hives - Chair}/LOV{Mr Lovesey}, we should suffer from the difficulty in getting good metering and power at low speeds. There should be no difficulty about slow running. We think it would be possible to connect the present twin carburetter on Phantom to a through pipe. For many years we have thought that most of these twin carburetters worked better with some through connection generally in the neighbourhood of half the diameter of the pipe. W.W. is sending you a design for a universal pipe for P.2. in cast aluminium which ought to enable you to fit any pair of single carburetters - i.e. up or down draught, and any single carburetter - up or down draught, with a through pipe, (but not horizontal ones which we think would need a different type of head - i.e. with half the induction pipe in the head.) For good slow running we think it is necessary to have throttle edge carburetion, therefore, our old carburetter and the S.U., may be poor in this respect. In our designs we have made this an important item, and if carefully proportioned by experiment will have much influence on good metering qualities. Mr. Lovesey has been so successful that we should utilise his experience and skill on this car work, or we shall be overlapping wastefully. R.{Sir Henry Royce} | ||