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).
Investigation into explosions in the silencer, comparing the causes between the Silver Ghost and Phantom models.
| Identifier | ExFiles\Box 66\2\ scan0256 | |
| Date | 7th October 1926 | |
| Hs{Lord Ernest Hives - Chair}/AJL2/T7.10.26. EXPLOSIONS IN SILENCER (SILVER GHOST) In connection with investigations carried out on Phantom cars relative to explosions in the silencer, we have carried out similar tests on a Silver Ghost car. It is a generally accepted fact that the Silver Ghost car is much more immune from this defect than the Phantom. A Silver Ghost car can, however, be madw to produce explosions in the silencer equally as violent and numerous as a Phantom. The main factor controlling the explosions is the strength of the carburation mixture admitted to the engine when coasting with small throttle openings. The normal range of mixture on the Phantom gives approximately the correct mixture for ignition under these conditions. The Silver Ghost engine however, requires a weaker mixture than that given by the normal carburetter range, in order to produce explosions. Thus on a Silver Ghost there is a greater factor of safety in this respect than on a Phantom, e.g. a given sized air leak in the induction system which will produce bad explosions on a Phantom car will not have the same effect on a Silver Ghost, the air leak must be larger on a Silver Ghost to produce explosions. Assuming that the petrol to air ratio is the same on both cars we deduce that the Phantom engine has not the same capacity as the Silver Ghost for firing small charges. Contd. | ||