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).
The development and testing of supercharger components including worm gears, carburetters, and blowers.
| Identifier | ExFiles\Box 140\1\ scan0128 | |
| Date | 4th February 1935 | |
| -2- We have in hand three alternative arrangements for mounting the blower, by which we hope to discover the best all round induction system. We propose also to work on a thermostatic control which will provide exhaust hot spotting during low speed running and on starting up only. Worm Gear. We have now completed 37 hours test bed running, and the worm drive has worn badly and become very noisy during tick over. The worms, which are of the orthodox type manufactured by David Brown & Sons, have worn very much more than the special Cone worms on the Graham car after 10,000 miles. These latter, however, are now becoming noisy, and we think it important that we should experiment with alternative types of drive. Carburetter. It appears at the moment that a fixed throat type of carburetter is the best suited to our purpose. Such an instrument will give us high torque at low speeds, coupled with good slow running. The greater restriction to air flow at high speeds may be an asset in restricting the maximum boost. We accordingly propose to do all future development work with proprietary brands of fixed throat carburetters, leaving the carburetter problem to the last. Blower Efficiency. We know the Graham blower to be very inefficient, and as a first step to improving the efficiency we are replacing the rotor, which is a rough casting, by one machined all over and with less clearance to the rotor casing. We also have in hand a blower of the same overall dimensions as the Graham, but incorporating a diffuser. We are anxious to know whether the diffuser will give rise to noise and whether the characteristics of such a blower will be suitable for motor car work. Road Experience. We hope shortly to fit the supercharged engine into a chassis. Hs{Lord Ernest Hives - Chair}/E.{Mr Elliott - Chief Engineer} Ll. Smith. | ||