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).
Collection of memos on the design and testing of exhaust systems to reduce noise on 25 HP and Phantom III models.
| Identifier | ExFiles\Box 104\2\ scan0275 | |
| Date | 15th October 1937 | |
| Spare - 523 To Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager}3/JH.15.10.37. DESIGN OF EXHAUST SYSTEMS. The following are extracts from original memos. relative to the necessity for having a large front expansion box on our exhaust systems. To By.{R.W. Bailey - Chief Engineer} c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Hdy.{William Hardy} Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}3/KW.17.9.34. 25 HP. Exhaust System. We have now concluded a number of experiments on 20GIV. with the 25 HP. Exhaust system, and consider that we have effected a considerable improvement generally; i.e. reduced the amount of noise emitted from the tail pipe, reduced the "titter" from the front of the exhaust system, and practically eliminated all traces of "boom" throughout the whole range of the car. Our experiments have shown us that with regard to "boom" periods, the chief factors are the front expansion box and the extreme rear end of the rear silencer, and the tail pipe noise is mainly affected by the continuity or otherwise of the centre pipe in the rear silencer, and in any future experiments to still further improve the exhaust system, these are the main factors to bear in mind. Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager} -------------------- To E.{Mr Elliott - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to By.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}2/JH.31.8.36. Phantom III Exhaust System. With regard to the 30 M.P.H. exhaust boom on Phantom III cars | ||