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).
Investigation into an objectionable groaning noise from the silencer on 20/25 HP cars.
| Identifier | ExFiles\Box 104\2\ scan0072 | |
| Date | 17th November 1932 | |
| Hs.{Lord Ernest Hives - Chair} C.E. BY.{R.W. Bailey - Chief Engineer} Wor.{Arthur Wormald - General Works Manager} X 5230 EP{G. Eric Platford - Chief Quality Engineer}12/H17.11.32. re 20/25 HP. SILENCER PERIODS. (Stamp: RECEIVED NOV 21 1932) In our tests of complete new cars for delivery, we have been disturbed by certain objectionable groan periods, which have been traced as emanating from the silencer. We find the trouble also exists on new chassis on test in a lesser degree, as demonstrated to you the other day. We feel that the trouble has recently become worse. 18-G-IV, now fitted with "resonance silencer" as per Standardisation sheet, issued today, does not have this trouble, and exhaust noise generally is very good. We suggest, however, that owing to the variations in this complaint on different chassis, this should be tried out and confirmed on other cars. We suggest one is fixed on Wor{Arthur Wormald - General Works Manager}'s car, No. 17-G-IV, also some similar silencers should be made up immediately and tried out on one or two complete cars, "bad cases" or complaints from customers which we shall possibly receive. We consider the adoption as standard of this type silencer an urgent matter. We also consider that investigations should be made to see if improvements can be made to this trouble by some easy alternative to existing silencer or its mounting, as we did in the early 20-HP car silencer groan period troubles. We are doing what we can on Production where possible. EP.{G. Eric Platford - Chief Quality Engineer} EB | ||