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).
Series of tests on flexible engine mountings to investigate and resolve issues with clutch jagger and engine smoothness.
| Identifier | ExFiles\Box 104\1\ scan0225 | |
| Date | 10th October 1934 | |
| x 5085 To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager} Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}2/KW.10.10.34. C C to Wal By Flexible Engine Mounting. We have now completed a series of tests with a central engine mounting in conjunction with the Terraplane rubber engine mounting on chassis 20-G-IV, with a view to confirming the results obtained by G.W. Hancock on 28-EX in France. Our first test was with both engine mountings fitted and the spring loaded pedal shaft link to N.Sch. 4181 also fitted. This condition gave us no sign whatever of clutch jagger, but we lost an appreciable amount of engine smoothness, particularly from 10 M.P.H. to 40 M.P.H., and the Steering joggles became more noticeable. Wing and headlamp movement appeared about the same. In the second test we removed the pedal shaft link and immediately ran into very bad clutch jaggers. All other conditions were similar to the first test. We next removed the central engine mounting and regained our engine smoothness, and reduced the amount of steering joggles, but the clutch still jaggered. We then refitted the pedal shaft link and tried it both in its standard spring loaded condition and built up solidly, but it had no effect upon clutch jaggers. We then fitted one of the front links from the engine to the 5th cross member, leaving the pedal shaft link on also. This practically cured the clutch jagger except under abnormal usage. From these tests it will be seen that the pedal shaft link was not effective in dealing with clutch jagger whilst the engine was allowed any forward movement, but when the forward movement was stopped, the clutch jaggers disappeared. This meant of course that the engine forward movement had to be restricted to such an extent as to keep it in the same position as the rigidly mounted pedal shaft. This led us to assume that working in the opposite direction, if we could make the pedal shaft move uniformly with the engine we should obtain the same result. | ||