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).
Technical discussion on carburetter design, spark plug configuration, fuel delivery systems, and ignition types.
| Identifier | ExFiles\Box 96\1\ scan0039 | |
| Date | 26th October 1935 | |
| (2) E.1/HP.26.10.35. road is not much good for travelling quickly unless the gearbox is used all the time, certainly in this country. With regard to four carburetters, these have the advantage of ensuring good distribution by quantitively dividing the fuel supply into four equal parts before it is released to the induction system. The carburetters as fitted represent two sets of Bentley induction systems. With regard to the 14 m/m plugs we venture to predict that these will be used as standard by everybody in the near future. Their smaller bulk enables us to get in two plugs per cylinder, which in this small diameter of cylinder would be otherwise impossible. The inside plugs can be changed with reasonable facility by means of a suitable long spanner that we supply. We believe we are unique in fitting a 12 cylinder engine with separately opposed sparking plugs which, combined with the form of combustion head used possesses very definite advantages. The autovac petrol feed is not suitable for carburetters high up on the engine where most modern carburetters are as there would be insufficient feed head. When the autovac was first introduced on cars generally it gave a considerable amount of trouble, but now that it has become reliable it is natural that people should be reluctant to change it for something new. We see no reason why petrol pumps should not give steady and reliable service. With regard to abandoning the magneto, this is/ becoming an archaic form of ignition, in no way electrically superior to battery ignition and expensive and difficult to drive. It also makes the provision of automatic advance, control | ||