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 difficulties with the butterfly exhaust valve on the New Phantom and Silver Ghost models.
| Identifier | ExFiles\Box 66\2\ scan0131 | |
| Date | 4th December 1925 | |
| R.R. 493A (50 H) (D.D. 31. 12-6-25) J.H.D. EXPERIMENTAL REPORT. Expl. No. X8230 REF hsl/LG5.12.25. To BJ. from Hs. {Lord Ernest Hives - Chair} c. to PN. {Mr Northey} BUTTERFLY EXHAUST VALVE ON NEW PHANTOMCodename for PHANTOM I. X8230 BJ9/H4.12.25. The difficulties with the butterfly valve in the exhaust pipe are very well known. This particular unit is exactly the same as we use on the Silver Ghost cars. We had similar trouble on the Silver Ghost cars. This matter has been considered by R. {Sir Henry Royce} at various times and the conclusion he arrived at was that it would always be very difficult to operate a valve in the exhaust pipe which would remain reliable. It was chiefly for this reason that we have been running on experimental cars water heating instead of exhaust heating. It has been proved however that the water heating is not very successful and further experiments are being made with steam heating. We consider the car PN. {Mr Northey} complained of, must have been exceptional, because at the present time we are anxious to try out a suggestion which PN. {Mr Northey} made to us to prevent squeaking and although we have tried all the experimental cars and have been round the production cars and so far we have not been able to find a car with squeaky valve on which we can try out this scheme. No doubt we shall obtain one shortly. Hs. {Lord Ernest Hives - Chair} | ||