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).
Tests conducted on a 'Brown' silencer for a 25 HP exhaust system.
| Identifier | ExFiles\Box 104\2\ scan0124 | |
| Date | 14th November 1934 | |
| Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}18/KW.14.11.34. 25 HP. Exhaust Systems. We have been carrying out tests with the "Brown" silencer, and give below a summary of the results obtained :- This silencer consists of a very heavy material outer shell (.187" thick) and 3 built up multi-tubular baffles spaced at intervals by distance tubes. the exhaust gases passing in turn through a tubular baffle and then into an expansion chamber. It is a very poor silencer, the tail pipe noise is considerable, and there are very heavy and unpleasant booms from 20-45 m.p.h. on forward and 50-20 m.p.h. on the over-run. The diameter of the tubes through which the gases have to pass is only .100" and I am afraid they would very quickly become choked up with carbon deposit. The weight of the system when fitted to the car is 52 lbs. 4 ozs. Hs{Lord Ernest Hives - Chair}/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} H.{Arthur M. Hanbury - Head Complaints} Whyman. | ||