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).
From the 'Britannic' proposing a test programme to improve snap opening on Bentley carburettors.
| Identifier | ExFiles\Box 173\1\ img032 | |
| Date | 5th January 1934 | |
| COPY. USA "BRITANNIC". Hs.{Lord Ernest Hives - Chair} __ 5.1.34. We should berth in New York Monday morning. I have been considering the snap opening up of the Bentley. I am sure that on American fuel and under winter conditions here it will be criticised, because it was already showing up in Derby. As we have two test bed units on Bentley work, could we not devote one to this problem, in view of the fact that any results will be applicable to the SpectreCodename for Phantom III. The programme I suggest is as follows :- (1) 1 1/4 Carburetters. We have ascertained no loss of power with these on standard induction pipe. Get a casting made with reduced cores and make tests to see how much the bore of the pipe can be reduced before the power drops appreciably. Make tests with smallest permissible pipe and these carbs. to see if snap opening up improved. (2) S.U. Piston Damping. From past experience one would say that damping the S.U. piston movement would give us exactly the momentary richening up that we require. S.U's never seem to have done this seriously. An adaptor dashpot stuck on the top of the ordinary S.U. should not be difficult to make. Presumably it should act when the piston is rising only. Skinner ought to come over because, with a decent consumption, we have always been weak snap opening up at 30 m.p.h. and I believe everyone else finds the same thing. | ||