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).
Standardisation and testing of the Phantom II resonance type silencer for Continental cars.
| Identifier | ExFiles\Box 14\6\ Scan263 | |
| Date | 23th September 1932 | |
| ✓ 7230. x7120. To Sg.{Arthur F. Sidgreaves - MD} From Hs.{Lord Ernest Hives - Chair} c. to WGr. c. to Ey. c. to L. c. to Da.{Bernard Day - Chassis Design} Hs.{Lord Ernest Hives - Chair} 2/MJ.23.9.32. P.2 RESONANCE TYPE SILENCER. It has been agreed that the P.II resonance type silencer shall only be standardised for the Continental type cars. This silencer was run 10,000 miles on 19-EX. The exhaust system on 19-EX. also included mild steel fittings. All the lagging had also been left off. There was no criticism on exhaust noise on this car by either Sales or Works officials. There was slightly more exhaust noise. We were also able to measure that there was a 20° rise in temperature in the driving compartment with the lagging left off. Therefore when we fitted up 58-GN. we put the lagging back again and it follows when we have the lagging we must have Staybright material. The scheme on 58-GN. was proposed as standard for all cars. Now that it has been agreed that the resonance type silencer shall only be used on Continental cars we are anxious to adopt the scheme as run on 19-EX. That is, mild steel pipes without lagging. The amount of extra noise is very small and would not be criticised on Continental type cars, and the fact that most Continental cars have louvred bonnets means that there would be no appreciable rise in temperature on the front seats. It will mean that the exhaust system will be less costly and we believe give less trouble. We shall also be standardising the system which proved successful on the 10,000 miles test. Hs.{Lord Ernest Hives - Chair} | ||