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).
Proposed modification to the Phantom II exhaust system to reduce noise.
| Identifier | ExFiles\Box 14\6\ Scan231 | |
| Date | 27th November 1931 | |
| 87230. To RHC.{R. H. Coverley - Production Engineer} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Lid.{A. J. Lidsey} PHANTOM II EXHAUST SYSTEM. We have recently found that we do not lose any power on the 25 HP. car with the small manifold and downtake (1.600 inside dia.) and at the same time greatly reduce the tendency of the exhaust system to be "tinny" and "boom". We therefore wish to try a "pro-rata" size of pipe on the 40/50. This is 2.250 inside dia. and a length of pipe is available in 10 gauge which we think will be suitable. In order to get a smooth flow from the manifold it will be necessary to cast a special one having the core altered so that the exit diameter is 2" instead of the existing 2.800". In order to simplify the experimental bits necessary we could use the existing flange put on the smaller down-pipe with a distance collar. We should like the pipe made up to suit the front expansion box having the lead in at the end as per attached sketch. The silencer to be used with this system is to sketch Hs.{Lord Ernest Hives - Chair}476. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||