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).
Graph comparing the maximum power figures of different single cylinder engine heads.
| Identifier | ExFiles\Box 134\1\ scan0118 | |
| Date | 23th December 1938 guessed | |
| CURVE a.{Mr Adams} SINGLE CYLINDER POWER COMPARISON. MAXIMUM POWER FIGURES ① Nᵒ 5 HEAD RATIO: 6·4 IO: TDC IC: 30°PBDC. EO: 50°B. EC: TDC ② BEN HEAD RATIO: 6·6 VALVE SIZES: 1·5 IN. 1·4 EX. IO: 10°B IC: 30°P EO: 55°B EC: 3°P ③ BEN HEAD RATIO: 6·4 VALVE SIZES: 1·4 IN. 1·3 EX. I.O.: 4°B I.C.: 51°P E.O.: 51°B. E.C.: 7°P. Y-AXIS: M.E.P. X-AXIS: R.P.M. | ||