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).
Power output tests of a High Power Head for a Bentley engine, comparing results and showing percentage gains.
| Identifier | ExFiles\Box 134\2\ scan0107 | |
| Date | 16th February 1937 | |
| Rm{William Robotham - Chief Engineer} from Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} Rm{William Robotham - Chief Engineer}/Ed{J. L. Edwards}/M.16.2.37. Power Output of High Power Head. Power tests have been carried out on the standard small bore S/C Bentley and the High Power Head in an attempt to line up with results obtained previously by Wd{Mr Wood/Mr Whitehead}/CHP. Though actual figures have not been reproduced, the relative curves are comparable and percentage gains of the High Power Head over the standard head are given below. The original curves obtained by Wd{Mr Wood/Mr Whitehead}/CHP are shown on Fig. I. and the curves obtained now, on Fig. II. The difference is put down to the fact that the H & F water brake used for the original tests was very old and probably inaccurate. Percentage Gains. | RPM | 1000 | 1500 | 2000 | 2500 | 3000 | 3500 | 4000 | 4250 | 4500 | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | Wd{Mr Wood/Mr Whitehead}/CHP | 8.2% | 5.7% | 5.7% | 5.6% | 10.7% | 15.1% | 20.0% | 24.3% | 25.0% | | Rm{William Robotham - Chief Engineer}/Ed{J. L. Edwards} | 9.5% | 9.9% | 8.8% | 9.8% | 11.6% | 14.4% | 20.9% | 23.5% | 25.8% | As will be seen except at speeds between 1500 r.p.m. and 2,500 r.p.m. the differences are within 1%. This is considered to be quite as accurate as experimental error will allow and it is now proposed to go on with the programme schemed out for this unit. As a matter of interest main engine powers were estimated and are shown on Fig. III. Rm{William Robotham - Chief Engineer}/Ed.{J. L. Edwards} | ||