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).
Improving carburettor efficiency, control, and starting procedures.
| Identifier | ExFiles\Box 13\4\ 04-page050 | |
| Date | 8th November 1932 | |
| -2- Hs.{Lord Ernest Hives - Chair}7/MT.8.11.32. Cont'd.{John DeLooze - Company Secretary} EFFICIENCY.- It will be seen from some of our curves that we can still obtain more power from the T.U. than we can from the R.A. semi expanding carburetter. There is no fundamental reason for this except that we lose efficiency in the changing the direction of the air passing through the air valve. It may be that with some guide vanes or some attempt at stream line flow we could improve this. Although it might be argued that the last bit of power is not important we cannot afford to throw anything away and the design of the carburetter is such that it should enable us to use one of the maximum size and yet still give us good acceleration. CARBURETTOR CONTROL.- This still leaves something to be desired because at the present time the range of our mixture controls varies from 30% just as the air valve is lifting and 2% when it is at the top. The steering column control also gets a bit difficult because for starting we have to put it right 'over rich'. In order to be sure of a start we have had to make this 'very rich'. As soon as the engine has started it is necessary to leave it 'full rich' until it has got going. If the throttle is opened up starting richness becomes less. If, however, the engine is run down to the idle position with it full rich it will immediately choke up with petrol and stop. It is nothing like as foolproof in the handling as our present set of controls. Another feature of course is that the extra oil is now left as a separate control and can very easily be forgotten, whereas the arrangement of coupling this to the starter carburetter has proved to be very effective. We consider the three points we have mentioned i.e. Starting, Controls, and Efficiency, are points which demand design attention. It may mean that in the first care we shall still have to retain the present starter carburetter and controls. Hs.{Lord Ernest Hives - Chair} | ||