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).
Slow running adjustment and throttle coupling for the 4¼-Litre Bentley.
| Identifier | ExFiles\Box 103\5\ scan0159 | |
| Date | 29th March 1939 | |
| To By.{R.W. Bailey - Chief Engineer} from Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} c. Da.{Bernard Day - Chassis Design} 4¼-LITRE BENTLEY. SLOW RUNNING ADJUSTMENT. For some considerable time opinion has been varied regarding the most suitable method of coupling the throttles together of two S.U. carburetters, and a subsequent method for adjustment for same. In order that we might make use of past experience we appealed to Depots through GWH.{George W. Hancock - Head Chateauroux} The position is therefore summed up in Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}6/N. 25.3.39, where he says that the only thing wrong with the present production method is that the return springs become fatigued. For B.V. the design caters for two throttle stops (one on each carburetter), but one return spring. Two throttle stops are not suited to the particular type of coupling adopted, for the following reasons:- (a) The balancing of the throttles is done with the engine stationary, and throttles closed tight. Then the coupling is locked up (method as laid down in the instruction book). (b) Once having done (a), it is more than likely that the other throttle stop will never serve any useful function. It is therefore suggested that one throttle stop is deleted, and the matter of the throttle spring dealt with as a separate issue. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} ENCLOSURE No 27 "JUSTSO" | ||