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).
Letter from The Zenith Carburetter Co. Ltd. discussing the performance of twin versus single carburetters on 6-cylinder engines.
| Identifier | ExFiles\Box 122\3\ scan0072 | |
| Date | 11th August 1938 | |
| The ZENITH CARBURETTER CO LTD 1033 C. T. Salt CARS DRIVEN BY OUR STAFF ARE AT CUSTOMERS OWN RISK AND RESPONSIBILITY. TELEGRAMS: ZENICARBUR, PHONE, LONDON. CODE: A.B.C. 5TH EDITION. HONEYPOT LANE, STANMORE, MIDDLESEX ADJOINING QUEENSBURY UNDERGROUND STATION ALSO AT LYONS, PARIS, DETROIT, TURIN, BERLIN. TELEPHONE: WORDSWORTH 2213. 11th August 1938. W. A.{Mr Adams} Robotham Esq., Messrs. Rolls-Royce Ltd, D E R B Y Dear Mr. Robotham, With reference to the question of Twin Carburetters on 6 cylinder Engines, I wrote to our French House for their opinion, and they have answered to-day as follows:- "We find in general that twin carburetters give every satisfaction on 6 cylinder engines. One advantage over the single carburetter is to give a better torque between 1000 and 2000 R.p.m and this is one of the improvements that are looked for in 6 cylinder Cars. The improvement of torque that can be obtained with a twin carburetter is about 8 to 12% better than with a single one. At higher speeds there is not much difference between the twin and single carburetter as regards power. The setting of the twin carburetter on such engines is rather different from that of a single carburetter and especially we generally find it necessary to do away with the power jet at full throttle as the tendency with engines equipped with twin carburetters is to have a weak part throttle curve. With regard to distribution, this is absolutely a question of the design of the inlet pipe and of the hot spot, the latter being just as indispensable with a twin as with a single carburetter. If you would send us drawings of the pipes that have been used by your Clients, we should be very pleased ..... | ||