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).
Further tests conducted on a hot spot pipe, including the use of a deflector and comparisons with American cars, concluding on modifying the throttle.
| Identifier | ExFiles\Box 75\2\ scan0228 | |
| Date | 26th May 1921 | |
| Contd. -6- Hsl/LG26.5.21. first position of hot spot. We made further tests with this hot spot pipe by fitting a small deflector. This consists of a 5/16 screw, screwed on the underside of the cross pipe close to the "T" joint with the flat on it. This flat projects into the pipe about 1". We could, by adjusting this, make a very big difference in the results obtained from the pipe, we could, by adjustment, get equal distribution. We have got to admit, however, that so far, the pipe which is giving us the best results is a standard pipe with the 1" pipe through the centre with no heat whatever. We shall not be satisfied until we can reproduce these results consistently. We feel certain that we shall, very shortly, be able to say that we can do so. The standard we are striving for is a better result than we obtain on the Marmon car or other American cars we have. If we run them with the same quality of petrol and the same temperature of engine, we do not get such good results as it is possible to get on our own car. Conclusion. The results of our tests how that whilst we have to deal with liquid petrol in the induction pipe we shall always be liable to any slight differences in the contour of the pipe upsetting the distribution. Therefore, the best practical arrangement appears to be to make the throttle into an effective hot spot. We have tried adapting the present throttle, but the jacket does not lend itself. During our tests we have proved that the heating of the throttle is a very definite advantage but there is contd:- | ||