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).
Performance graph for a 40/50 HP engine, plotting Horse Power and M.E.P. (Mean Effective Pressure).
| Identifier | ExFiles\Box 181\M7\ img076 | |
| Date | 1st May 1923 guessed | |
| HORSE POWER M.E.P. (LBS PER □") HP 40/50 BENCH... HP 40/50 DYN... 64 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 500 750 1000 | ||