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).
The issues with exhaust cut-out noise and customer complaints.
| Identifier | WestWitteringFiles\L\Jan1924-March1924\ Scan89 | |
| Date | 11th February 1924 | |
| R.B. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} -2- Expl. No. 4269 REF:Hs{Lord Ernest Hives - Chair}2/LG11.2.24. EXPERIMENTAL REPORT. If we make use of that with the cut-out open, we gain very little in H.P. due to the cut-out, and also on the road there is not sufficient difference in the noise to give any warning. There is not sufficient difference in the noise to use it for testing the running of the engine. Sales and our customers are very critical on exhaust noise. They have complained of the exhaust noise on the 20 HP. from the first cars. We have recently recommended the slightly less diameter swan-neck pipe which decreases the amount of exhaust noise without affecting the power. One of the chief difficulties with the butterfly type of exhaust cut-out is the noise which is caused by the fluctuations in the pressure if there is any slack in the mechanism. This is usually noticeable when running with the throttle shut. It is the same problem as the butterfly for controlling the exhaust to the carburetter hot spot, and a satisfactory solution should overcome both troubles. The cut-out fitted to 5-G-11, as far as we are aware, closely follows the N.sch. but as there has been trouble all along with the noise, it may have been altered since it left the Works. We also recommend that we should get out a modified operating lever for the cut-out which would not necessitate the large gap in the floorboards. We think this is very necessary when we have gone to such trouble to do away with any gap in the clutch and brake pedals. Hs.{Lord Ernest Hives - Chair} | ||