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).
Test report page detailing engine performance issues and potential improvements related to the throttle and induction pipe.
| Identifier | ExFiles\Box 50\3\ Scan271 | |
| Date | 15th January 1924 | |
| -2- January 15, 1924. Test 3. It was not possible to obtain a reading at 500 R.P.M. as engine loaded up badly due to throttle and branch of induction pipe being quite cold. It is possible the shape of the Derby Hot throttle and induction pipe may contribute slightly to the power results, as these are superior to No.1 although the throttle was unheated. The induction pipe is one where the oval holes in pipe are left smaller than the elbows so as to present sharp corners to the gases and, according to Derby, improve distribution. The throttle remained cold during the entire test (NO.3). Tested on the road with the same carburetter setting as used on the dynamometer the mixture was far too rich so that the gas consumption could be considerably improved over that obtained on the dynamometer. The road performance is exceptionally good but the Barometer reading was high, 30.2 when the road test was made. Tests on dynamometer were made with Barometer at 29.9. After a 6 mile run it was possible to keep the hand on the main part of the throttle body and short branch of induction pipe, the under side of throttle being much warmer. It may be possible to obtain some advantage by more uniformly heating the throttle by using a baffle in the jacket. Arrangements are being made to carry out tests using the exhaust from the front cylinder block as well as rear to heat the throttle. As far as these tests go they show that giving more heat to the throttle is likely to considerably improve the car's performance. Three separate sheets of tests are attached hereto. E. {Mr Elliott - Chief Engineer} W. C. E | ||