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).
Experiments and proposed modifications to reduce exhaust noise on a 40/50 HP car.
| Identifier | ExFiles\Box 38\4\ Scan076 | |
| Date | 19th November 1924 | |
| To B.J. from Hs.{Lord Ernest Hives - Chair} c. to PN.{Mr Northey} BY.{R.W. Bailey - Chief Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} MX.{John H Maddocks - Chief Proving Officer} 43436 HsS/LG19.11.24. 40/50 HP. EXHAUST NOISE. X3436 We should like to know whether you are satisfied with the reduction in the exhaust noise on 11-AU car, because if so, instructions could be given to make all cars similar. We have continued our experiments to reduce the exhaust noise further, and we have a scheme by which this car be carried out. It means, however, more alterations. It would mean new front half for the exhaust manifold and alterations to the exhaust pipe. It also entails a further drop of 1 to 1 1/2 HP. at 2000 r.p.m. In any case, we are not in a position to carry out these alterations immediately because so far we have only arranged it temporarily. It would mean making new castings and testing before we could recommend it for adoption. The modification which has been fitted to 11-AU to reduce the exhaust noise only consists of lagging the pipe between the front and rear silencers. This does not in any way affect the power, and also cannot affect the reliability. Hs.{Lord Ernest Hives - Chair} | ||