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).
The Vaporiser Scheme and Pilot Jet used on American-made cars.
| Identifier | ExFiles\Box 50\3\ Scan230 | |
| Date | 18th August 1922 | |
| BY from EP. {G. Eric Platford - Chief Quality Engineer} c. to Hs. {Lord Ernest Hives - Chair} c. to E. {Mr Elliott - Chief Engineer} Re. Vaporiser Scheme and Pilot Jet used on American made Cars. I attach Blue Prints A.1414 and A.1371, showing the Doris scheme and the Pilot jet scheme, which is now fixed as a standard fitting to the American made chassis. This scheme has now been applied to the cars for some time and was actually used on several cars during the past winter, and they are quite satisfied that with the scheme the cars are serviceable, even during the coldest weather, whereas unless these are fitted the cars are not serviceable, a point I am certainly able to agree with, and which Hs. {Lord Ernest Hives - Chair} will also confirm. They agree that this Vaporiser scheme is not all that could be desired, and there is still scope for improvement so far as carburation is concerned when using the American type of Gasoline. At the same time it has proved itself during the past winter as satisfactory as any other type of American made car, and customers who have complained bitterly that the cars were unserviceable have been quite pleased and perfectly satisfied with the running of the engine after this scheme has been applied. I was particularly impressed when testing various chassis at Springfield with the improvement in the engine so far as hill climbing, acceleration and such conditions where one requires the engine to run under full throttle conditions at low engine speeds. There were no signs of "loading up" and they now appear to be entirely free from the troubles which had been experienced, i.e. dilution of the oil in the crankchamber, overoiling of ignition plugs, faulty lubrication of the cylinders, poor petrol consumption etc. It also has the advantage that the power does not appear to be sacrificed at high engine speeds. The scheme also has the advantage that it can be fairly easily applied to existing cars. Although I took with me a hot throttle scheme, I was not able to try this out, as they had no cars available, and the one supreme effort during my visit was to turn out cars to compete with the ever increasing orders. In any case it is not considered that the comparative tests would be complete unless taken during the worst cold weather conditions, which only exist during the winter. They have promised, however, to make comparative tests with the existing scheme and with the hot throttle scheme on the same CONTD. | ||