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).
Features and performance of various carburettor types for the Phantom model.
| Identifier | ExFiles\Box 13\3\ 03-page389 | |
| Date | 29th February 1932 | |
| E.{Mr Elliott - Chief Engineer} HS.{Lord Ernest Hives - Chair} } FROM R.{Sir Henry Royce} RG.{Mr Rowledge} } (At Le CanadelHenry Royce's French residence.) X7080. R2/M26.2.32. Sent from VV. 29.2.32. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} PN.{Mr Northey} CAR WORK - CARBURETTERS. X.7080 X.5080 I thank Mr. Elliott for his memo. re. our vertical semi-expanding carburetter for Phantom. I was very pleased to read that this was promising well and looked a very suitable instrument of good appearance. One will realise that it must not be expected to attain perfection straight away, but it has many features that are thought to be necessary, and are not all found together in any other carburetter: (1) Throttle edge carburation (consistent & good idling etc.) (2) Jet control of both low and high speed jets. (3) Starter enrichment control. (4) Exhaust heat. (5) Less fire risk. (6) RR. appearance, etc. SUs. cannot be considered right until they have many modifications. Personally I do not think they will ever be consistent over a long life period unless they are only allowed to cut down to say a third or a quarter max: area, and then do the fine throttle opening by throttle edge carburation. On our Phantom they appeared extremely ugly. The Expl. Dept. have now had: (a) Twin carburetters, and we have decided that the 2 separate ones are better than these. (b) Separate ones which seem so good for power at high and low speeds on J.L., but we are not sure about all the other features. These might be excellent for continental models (c) Semi-expander type, down-draught and updraught. So that designers have catered pretty completely for their wishes, it is not unreasonable to expect that the Expl. Dept. will make something of one or even two of these now that they have had considerable experience. Consistency and economy of fuel are necessary features even more than the last even 10% of HP at high speeds, which are so rarely reached. -1- | ||