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 with a lighter 20 HP flywheel, with comparative notes from a Chrysler test drive.
| Identifier | ExFiles\Box 104\1\ scan0009 | |
| Date | 3rd May 1928 | |
| Hs.{Lord Ernest Hives - Chair} from E.{Mr Elliott - Chief Engineer} c. to BJ. RE. LIGHTER 20 HP. FLYWHEEL. [word crossed out] 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} | ||