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).
Main points and experimental purposes of a dual induction system for the B.60 engine.
| Identifier | ExFiles\Box 147\3\ scan0126 | |
| Date | 10th August 1938 | |
| Rm.{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} c. to By.{R.W. Bailey - Chief Engineer} c. to Mr. Walker (P.S.) DUAL INDUCTION SYSTEM. The main points concerning the scheme are as follows:- (a) It may enable the use of a large free area induction system (being controlled at low speeds) thus enabling the best use to be made of the improved breathing of B.60 engine. (b) It is intended to use two carburetters per engine of the modified type shown on the drawing. This is desirable in order to keep the size of air valve within reasonable limits, and also to control "ramming" at middle and low speeds. It is intended to use the latest type of hydraulically damped air valve. (c) The leverage between throttles should be such as to allow a certain amount of free movement for the low speed throttle for tick-over adjustment. At this position, the larger throttle is held shut by coil spring mounted on its own throttle spindle. If possible, the duration should be adjustable during which the main throttle is closed. (d) With further reference to the drawing Rm.{William Robotham - Chief Engineer}494, it will be noted that the main carburetter has two jets, and two needles; the latter being controlled by one piston. At low speeds, the high speed jet is kept out of action by being in effect "capped" by the piston itself until such time as it becomes uncovered and so comes into action. It is intended for experimental purposes to have a series of main jets made of different lengths, so that the period of being "capped" can be lengthened or shortened. | ||