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 cause and prevention of self-ignition in the Phantom engine, discussing carburetter and exhaust valve modifications.
| Identifier | ExFiles\Box 66a\1\ scan0115 | |
| Date | 22th June 1926 | |
| To Hs.{Lord Ernest Hives - Chair} from R c. E.{Mr Elliott - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} Rg.{Mr Rowledge} Da.{Bernard Day - Chassis Design} Ry. PN.{Mr Northey} CWB X8080 RL/M22.6.26. RE PHANTOM SELF IGNITION. X.699. X.8230. X.8080. I am very pleased with Mr. Lovesey's research on the cause of self ignition on the Phantom engine. This phenomenon is a matter of great importance, but I hope that the risk of running backwards and firing the carburetter is not great: it should be tested. The way to avoid this is to use a sealed float chamber and an equalising passage such as we introduced into the aero carburetters. To increase the safety it may require a gauze over the intake, but we believe this fire risk is worst during starting, while the mixture is over weak and the engine fires into the carburetter. This also is avoided by the precautions mentioned above, and especially now that we use neither flooder or choke, owing to the unique use of our starting carburetter. Regarding the temperature of the exhaust valve, for many reasons it will be imperative for this to be reduced. There are many ways available, such as:- (1) Improved proportions of the valve head. (2) Umbrella type. (3) Larger hollow spindle - mercury cooling. (4) Increase of valve seat area. (a) Improvement in the conductivity of the metal of the valve. (6) Cooler aluminium head - bronze seat. R.{Sir Henry Royce} | ||