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).
Experiments with rubber isolated engine mountings to reduce engine roughness and vibrations.
| Identifier | ExFiles\Box 17\3\ Scan350 | |
| Date | 1st January 1929 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X7436 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG7.1.29. c. to BJ. SG.{Arthur F. Sidgreaves - MD} c. to WoR.{Arthur Wormald - General Works Manager} HS.{Lord Ernest Hives - Chair} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to E.{Mr Elliott - Chief Engineer} 'SS{S. Smith}' ENGINE MOUNTING. X7005 = We have tried four engine feet isolated with thin strips of sheet rubber. The foot consists of a piece similar in section to the frame channel fastened to the end of the solid foot and wedged in the channel by means of a strip of rubber 1/8" thick. The whole is pulled up tightly with clearance bolts to give torsional rigidity. We tried the front feet only treated in this manner first. The engine roughness brought up by solid feet was entirely eliminated but the radiator movement was still excessive. We then modified the rear feet and the result seemed a good compromise, but engine vibrations were rather too pronounced. We think that the rubber mounting at the rear must be more flexible than that at the front to ensure complete immunity from engine roughness. To complete our experiments we are therefore increasing the front mounting rigidity and decreasing the rigidity of the rear. From our results so far we can see no reason why something on these lines should not give us all that we require. We have carried out a number of tests reducing the effectiveness of the front hydraulic dampers. We find the improvement on the steering produced by the restrictions is very marked with a torsionally stiff frame, whereas radiator movement does not seem to be affected appreciably when we make the contd :- | ||