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).
Resume of work done on the Wraith model regarding noise complaints and subsequent modifications to the engine, suspension and other components.
| Identifier | ExFiles\Box 6\6\ 06-page208 | |
| Date | 4th June 1937 | |
| SECRET. Sg.{Arthur F. Sidgreaves - MD} from Mr. Hs.{Lord Ernest Hives - Chair} C. E.{Mr Elliott - Chief Engineer} C. D.{John DeLooze - Company Secretary} C. B. O.{Mr Oldham} No2. 600 RmG/R.4.6.37. The following is a brief resumé on the work that has been done on Wraith during the past month. It was accepted that the worst complaint was the noise level which existed in No.1 car. Noise was divided up into two sections:- (a) Engine and Suspension noise in the Driving Seat. (b) Tyre noise and road noise in the rear seats. These complaints were largely confined to the car with the limousine body on it, the close-coupled Wraith being, in our opinion, a very reasonable motor-car with regard to these problems. NOISE in THE FRONT GEARS. It was not considered advisable to spend a great deal of time on the engine unit and mounting, because this power plant is not representative of what will be fitted finally to the Wraith. It was ascertained, however, that the raised engine mounting smoothed out the idling vibrations, and made a smoother automobile at all speeds. This confirms the work done on the Bentley, and the raised engine mounting will be fitted to all Wraith cars from now onwards. A considerable amount of work was also carried out on slow running, and information obtained which will lead to modification of the final Wraith camshaft. We have also come to the conclusion that the moment of inertia of the Wraith flywheel might be increased slightly with advantage. With regard to suspension, the drilled frame of heavier gauge produced a noticeable reduction in noise, and we consider is a reasonable compromise. | ||