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).
Petrol consumption tests and carburettor settings for the Phantom III 32-EX.
| Identifier | ExFiles\Box 91\2\ scan0175 | |
| Date | 19th July 1937 | |
| 300a CHATEAUROUX. Rm{William Robotham - Chief Engineer}/IMW{Ivan M. Waller - Head of Chateauroux}/2/JAB.19.7.37. To. Rm.{William Robotham - Chief Engineer} c. Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems} 32-EX. PHANTOM III. Petrol Consumption. Further to our memo of the 17th inst., we shall have to postpone the consumption tests between top and overdrive until the axle job is done. Regarding the new carburetter which you are sending out, will you please send the necessary spare jets with it if you wish petrol consumption tests with reduced mixture strength to be carried out. It will be recalled that on 35-EX, with the reduced leverage float, we were able to go down from 058 to 056 on the main jets and from 060 to 054 on the bye-pass, but that reducing the jet sizes gave us no appreciable gain in petrol consumption on 35-EX. and put us right on the border line on leanness which is a bad thing, especially in cold weather. Bullamore has remarked on the freedom from flat spots or hesitation with 32-EX. compared to standard. The sparking plugs do not indicate over richness, and we should say that the present setting with the high pressure pumps and standard needle valve seat are an excellent combination, and we should prefer to leave things as they are. Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} | ||