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(1907 40/50 historic RAC 15,000 miles trial)) 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(1907 40/50 historic RAC 15,000 miles trial) 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(1907 40/50 historic RAC 15,000 miles trial) 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(1907 40/50 historic RAC 15,000 miles trial) engine however, requires a weaker mixture than that given by the normal carburetter range, in order to produce explosions. Thus on a Silver Ghost(1907 40/50 historic RAC 15,000 miles trial) 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(1907 40/50 historic RAC 15,000 miles trial), the air leak must be larger on a Silver Ghost(1907 40/50 historic RAC 15,000 miles trial) 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(1907 40/50 historic RAC 15,000 miles trial) for firing small charges. Contd. | ||
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).