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).
Over-run vibration on a 20 HP flywheel and considering rubber engine mounts as a solution.
| Identifier | ExFiles\Box 125\2\ scan0006 | |
| Date | 3rd May 1928 | |
| Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} c. to B.J. +4012 E1/M3.5.28. RE. LIGHTER 20 HP. FLYWHEEL. X.5300 X.5005 X.4012 Are we sure that the over-run vibration is not intensified by the use of a lighter flywheel? This vibration is appreciable on the 'twenty' down at WW., and appears to reach its max. at 38 - 40 m.p.h. when slowing down from above 50 with closed throttle. The rubber engine mounting may however permit us to use a lighter flywheel with impunity. A Red-head Chrysler I tried recently was very good on the overrun. The engine was mounted on rubber in a very crude fashion, by lining the inside of the chassis frame with a .250" layer of this material where the engine foot bracket was fixed, but apparently with the desired effect. This Chrysler had 6/1 comp: ratio, and was running on Ethyl petrol. The acceleration was like the proverbial scalded cat. I experienced no torque reaction periods, but it was a closed body. E.{Mr Elliott - Chief Engineer} | ||