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 with dual vertical axes for M.E.P. (Mean Effective Pressure) and Torque (Ft Lbs).
| Identifier | ExFiles\Box 181\M7\ img070 | |
| Date | 28th May 1928 guessed | |
| & M.E.P. Ft Lbs (LBS. PER. SQ: INCH) 60 180 70 210 80 240 90 270 100 300 | ||