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).
Method to overcome power reading difficulties during engine testing by running without reduction gears.
| Identifier | ExFiles\Box 179b\2\ img009 | |
| Date | 5th October 1932 | |
| -3- Hw/Yng./WJ.5.10.32. Cont'd.{John DeLooze - Company Secretary} It was necessary to run them without reduction gears to obtain the correct direction of rotation of the brake shaft. This increase in speed of the brake shaft has led to the trouble mentioned which took the form of a rhythmic surge thereby making it impossible to obtain power readings. Curve 103 "R" attached shews how the difficulty was overcome. R.35 engine, which was identical with R.37 apart from the direction of rotation, was used to take power and consumption curves from 2700 to 3200 R.P.M. From this a comparison between 3200 and 2700 R.P.M. was obtained thereby enabling handed engines to be tuned up at 2700 R.P.M. and a sound estimation of the power available at 3200 to be made. From the aforementioned curve it will be seen that the 300 M.P.H. intake air speed has added 165 BHP. to the figure for R.35 and that the power available at 3200 R.P.M. with the normal and sprint fuels is 2315 BHP. and 2425 BHP. respectively. We are assured that the engine compares satisfactorily with standard performance since the power check after the endurance test gave 1765 BHP. at 2700 R.P.M. with an open carburetter bowl. hs{Lord Ernest Hives - Chair}/H.R.Young. Attached: Curve 103 "R". | ||