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).
Letter to the Graham-Paige Corporation regarding supercharger testing on a 3 1/2 litre engine.
| Identifier | ExFiles\Box 140\1\ scan0103 | |
| Date | 20th December 1934 | |
| +209 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Smth.2/KW. 20th December, 1934. The Graham-Paige Corporation, Detroit, Michigan, U.S.A. For the attention of Mr. Kishline. Dear Sirs, We have now done a certain amount of test bed running with your supercharger boosting a 3 1/2 litre engine. We have been using an overall gear ratio of 5.5/1 from the crankshaft, taking the induction pipe over the top of the engine in a manner similar to that adopted by yourselves. With this arrangement, and using no induction heating apart from the water jackets in the blower casing, we obtained the results given in one of the charts attached. We get a considerable improvement in maximum power if we dispense with the heating on the blower, and we are about to experiment with induction pipe arrangements, and automatically controlled exhaust hot-spotting in the hope that we may obtain the best possible slow running and freedom from loading up when pulling at low speeds without sacrificing power as a result of undue heating of the charge. We shall keep you advised of our progress in this direction. We also propose to construct a blower incorporating a diffuser, and designed on lines which our experience with aero-engine blowers has shown to give the maximum efficiency. We have by us curves which we understand represent the performance of your supercharged engine. These are reproduced on one of the accompanying charts. The gain in output due to boosting seems to be very much greater than one would anticipate from the boost pressures. We should deem it a favour if you would be good enough to let us know whether or not the curves are | ||