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).
Tests verifying the results of different front engine mounting configurations.
| Identifier | ExFiles\Box 14\5\ Scan307 | |
| Date | 15th October 1934 | |
| To Hs.{Lord Ernest Hives - Chair} from Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} c. to E.{Mr Elliott - Chief Engineer} spec x7005 28-EX. We have been verifying the results obtained by the front engine mounting. We reverted back to the front flexible mounting and brought into prominence all the faults, steering not selective, excessive movement of front wings and headlamps, slight period of boom 25 to 35 M.P.H., and bad period of torque reaction. The clutch jaggers that were previously bad were surprisingly only obtainable when engaging the clutch on a steep gradient. We found that this result was due to omitting to fit the tie rod between the cantilever pedals and the clutch casing. When the tie rod was fitted clutch jaggers were bad under all conditions. We verified this by taking the tie rod off. Result clutch jaggers only produced as on previous test. Our next test was to make the front mounting of the engine solid. To do this we took the rubbers out of the front engine feet and substituted solid pieces of steel, making the engine feet solid with the frame, the tie rod being deleted. The result of this test produced bad shaking of the front of the car during the torque reaction period up to approximately 12 M.P.H., from that speed upwards one could feel the engine vibrations throughout the body. Wing and headlamp movement was not appreciably reduced. There was a bad period of boom from 25 M.P.H. up to approximately 38 M.P.H. There was no sign of clutch jagger. Steering did not appear to be improved. The next test was with the front central mounting only, i.e., no torque reaction dampers, no front engine feet. This brought us back again to where clutch jaggers could only be obtained under abnormal conditions. The torque reaction period slightly shook the front of the car up to 6 M.P.H. Above this speed the engine was as smooth as with the flexible mounting. The boom period was slight as with flexible mounting. Steering was more selective. | ||