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).
Adjustments made to resolve a 40 m.p.h. boom noise in a vehicle.
| Identifier | ExFiles\Box 5a\2\ 02-page321 | |
| Date | 5th December 1930 | |
| NS{Norman Scott}840 Hotel de France, Chateauroux, France. To Rm.{William Robotham - Chief Engineer} From A.B.R. 5/12/30. Re: 40 m.p.h. BOOM. We tackled the job yesterday on the lines suggested by Mr.Hancock. The best setting for the engine feet rubbers was found to be one turn back from the tightest position allowed by the internal distance tube. With the Torque Reaction Dampers entirely disconnected the boom was practically gone, but of course the low speed periods were very bad, and the best compromise arrived at was the N/S damper @ 1/4 lbs. and the O/S @ 1/2 lbs. This setting did not make the low speed periods materially worse, and the 40 m.p.h. boom was practically gone on the retard, and forward, although the volume was about the same, it only occurred @ 2 M.P.H. as against the original range of about 5 m.p.h. After these adjustments we ran the car without the fan belt, and we came to the conclusion that it had no effect on the boom. We are fitting the new brake shoes to-day and we shall not have any road mileage to report to-morrow. A.B.R. J B Roberts | ||