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).
Table of engine power readings at various RPMs with the exhaust cutout open and closed, along with commentary.
| Identifier | ExFiles\Box 65a\2\ scan0231 | |
| Date | 8th February 1929 guessed | |
| Revs. Cutout Closed. Cutout Open. HP. 500. 25.7 ~~191~~ 25.2 ~~2Ex~~ 750 38.8 39.8 1000 51 52.6 1250 62.5 64.2 1500 73.1 75.1 1750 82 86 2000 89 94.7 2250 87.5 104.5 2500 93 101.5 2750 97.8 . 102.5 There is, apparently, something wrong with the power readings at top speeds on 3rd gear. We should like to have an opportunity of trying these out again. It rather looks as though the cutout open figures are the most reliable. | ||