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).
Comparing the engine mounting systems of the SS chassis and a Chrysler car, and detailing experiments with different suspension configurations.
| Identifier | ExFiles\Box 125\2\ scan0027 | |
| Date | 7th January 1929 | |
| R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} 74012 E1/M7.1.29. RE. ENGINE MOUNTING. X.4012 X.7005 The SS.{S. Smith} chassis fitted with all rubber engine suspension achieves remarkable degree of smoothness over its full range of speed under all conditions of throttle opening and overrun. The Chrysler car we have tried in Derby gives quite a meritorious performance somewhat intermediate between the SS.{S. Smith} all rubber, and the SS.{S. Smith} with solid front mounting as regards smoothness, and the front end of the chassis appears to be quite steady up to 60 m.p.h. The chrysler has low gross weight and low axle gear in its favour. The engine is 4 point mounted and thin rubber is used at each point of attachment. The rear end of the engine is rigidly bolted to two brackets which in turn are bolted in the chassis frame on a lining of rubber about .250" thick. SEE ORIGINAL FOR SKETCHES. The scheme is crude but assuming a certain degree of freedom in the bolting the bracket can flex by parallelo-gramming the length of rubber 'X'. The rubber 'Y' does not appear to be set up. The front end of the engine is carried by the wheel case, this latter having feet resting on rubber washers about .250" thick on a cross member in the frame. Similar rubber washers are also used under the bottom ends of the clamping bolts securing these front feet. There is nothing remarkable about this scheme but it must be admitted that the results obtained are good. It is possibly not the whole story where the question of front end steadiness is concerned. With a view to trying a suspension somewhere between rigid and our present flexibility as you suggested, it was agreed to rig up an SS.{S. Smith} engine on solid feet at each end having rubber liners in the frame. We have now heard that with this mounting in front only, and with standard SS.{S. Smith} mounting behind, the engine is smooth, but the chassis front not sufficiently steady. | ||