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).
Progress report on design features for the Spectre model, including the gearbox, steering, engine mounting, and carburation.
| Identifier | ExFiles\Box 30\1\ Scan151 | |
| Date | 11th April 1935 | |
| -2- EA/Ru.17/KW.11.4.35. Other features on the SpectreCodename for Phantom III where progress has been made but design is not yet called for are as follows :- Gearbox. We have made definite progress in the reduction of gearbox noise by preventing the sound getting from the gearbox into the car. By insulating the change-speed mechanism, floorboards etc., the existing side shaft idling noise becomes passable. The gears under load are still open to criticism, but this feature too has been greatly improved by the accoustic treatment. We still have to try gears with the Cadillac tooth correction, the gearbox with ball bearings throughout, and the coarse pitch 45° helix gears with the endwise load on the shafts. We are, however, in a position to demonstrate the gearbox in a much better position than it was. Steering. We hope to be able to demonstrate the R-R Marles steering in SpectreCodename for Phantom III 2 to Mr. C on Tuesday. This steering shows up well in efficiency but there are small inaccuracies in the worm which produce tight spots. These do not occur in the Cadillac steering. This part was made by the Marles people, and we are taking the matter up with them. Possibly we shall find grinding necessary. Engine Mounting. The original scheme of engine mounting has so far proved satisfactory both for engine smoothness and clutch operation. We are experimenting with other mountings, however, of the Packard type, the object being to find a scheme where a misfire when the engine idles does not get through to the passengers. Slow Running Carburation. A lot of work has been done on this, using Bentley units as representing one bank of the SpectreCodename for Phantom III, with the engine unit tilted at 30° to the vertical, as on the 12 cylinder, we have a scheme which shows definite promise. We are now making pipes to fit it to the SpectreCodename for Phantom III car to get a full rehearsal before asking for a design. | ||