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).
Test results for various damper materials and observations on engine and exhaust noise.
| Identifier | ExFiles\Box 11\4\ 04-page116 | |
| Date | 20th July 1932 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} From G.W.H. Seen E 8/8/32 Seen By RECEIVED [stamp] BY [stamp] AUG 1 1932 Hotel de France, Chateauroux, FRANCE. 20.7.32. 19-EX. We have received your memo Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/1A.18.7.32. You will have noted in our report of 19.7.32 that we had fitted cotton duck fabrics to the slipper wheel and obtained better results. The periods have got to such a state that we decided it was no use carrying on. I am sorry you have gone to the trouble to send some out as it takes a week to 10 days even by air mail for parts to arrive here. We have kept the original cotton ducks, Ferodo discs, and the Rabestos that were fitted. The Rabestos are hopeless without we could have a dry friction. The Ferodo bonded with brass wire did not give us the same trouble, as we have met with using Rabestos, but you said it scored the plates, we said it showed no traces of scoring on our damper, so I thought it best to once more try the cotton ducks which up to the present we have not been able to replace for consistent results. The engine is decidedly smoother up to the present. The half-crankshaft period would not be found by an owner, and the rattle from the engine gears are passable. With regard to engine gear rattles, once they have really got bad, it appears very difficult to stop them, and most probably had we used cotton ducks in the first place they would not have developed. The Rabestos damper seems to almost go solid at slow speeds, which produces a knock as well as the rattles. We have built the damper up with a 20 lbs slipping load. Re. Exhaust System. I am sorry that my report was not clear with regard to the results after fitting the thicker pipes. There was no appreciable difference either with tinniness, exhaust beat in the front expansion box, and general exhaust noise. There is no doubt about the results as our method of comparing the results in our quiet garage, cuts out any questioning. (We were also very fortunate in having 60 JS.{Mr Johnson's Secretary} to compare with for comparative results.) In both cases the lagging of the downpipe, or | ||