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).
Page discussing tests on different valve forms and their effect on air and exhaust flow, with an accompanying diagram.
| Identifier | ExFiles\Box 134\1\ scan0011 | |
| Date | 12th July 1937 | |
| -6- (3) Valve Forms. Tests on valve shapes showed that a flat valve gave much better air flows on an inlet port than a tulip valve, and was further improved by fitting a domed head as shown. On the other hand, a tulip type valve gave a better exhaust flow. This appears to be a similar effect to stream-lining the tail of a car, but no figures for valves such as these have been obtained on test. Our own experience, however, tends to indicate that air flow results line up fairly well with power results, and it might be worth while trying out valves of the types shown. Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} | ||