Technical memo discussing experimental low single point front engine mounting designs for the Wraith III car.
| Identifier | ExFiles\Box 8\7\ 07-page80 | |
| Date | 25th August 1938 | |
| Dr/No. c. to Rm. {William Robotham - Chief Engineer} c. to Pe/SWD. DA. {Bernard Day - Chassis Design} 2/G.25.8.38. Aill 622. WRAITH III. ENGINE MOUNTING (LOW SINGLE POINT FRONT). WYMAN Please receive herewith :- E.CD.814 Front Engine Mounting. Wraith III. E.CD.840 Rear Engine Mounting. Wraith III. These designs are further to E.CD.810 and E.CD.832 which were instructed by DA. {Bernard Day - Chassis Design} 8/G.18.8.38. and consist of a low single point front engine mounting to be used in conjunction with the single rear mounting at present used on the Wraith III, and with the two inclined torque rubbers altered to bring the engine oscillation line to pass through the axis of the change gear mechanism in order to avoid transmitting the engine movement through to the change gear lever. On E.CD.814 we have shown in figure (1) an application of the Oldsmobile front support rubber to the Wraith III car, and also in figure (2) a support rubber of similar shape to our existing rear support rubber, and we suggest that the figure (2) design should be tried. It should be noted that with this design of engine mounting, the oscillation line of the engine passes below the centre of gravity of the engine. A further test could be made by using the modified rear suspension to E.CD.840 along with the standard high front engine mounting. This would bring the oscillation line nearer to the centre of gravity of the engine and still keep it near to the gear change mechanism point. Other combinations of these front and rear mountings could also be experimented with, and from the results obtained useful data would be available for future designs for engine suspensions for which at present no data is available for design reference. When using the front mounting E.CD.814 there is no necessity for the additional cross member E.CD.832, which is for use only with E.CD.810 mounting. We have shown the bracket for fixing the engine support member to the chassis frame on E.CD.814 as being bent from sheet for the experiment. This, of course, would be designed as a pressing for a production job, also the inner | ||
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).