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 of engine power output (B.HP) against engine speed (R.P.M.) for a 20 HP engine, comparing standard and increased compression ratios.
| Identifier | ExFiles\Box 19\7\ Scan087 | |
| Date | 1st May 1926 | |
| 20 H.P ENGINE - POWER OUTPUT WITH INCREASED COMPRESSION RATIO CORRECTED FOR BAR 760 m/m AIR 12°C B.H.P. R.P.M. 5.45 TO 1 COMPn RATIO CALCULATED FOR 5.45/1 RATIO STD COMPn RATIO 4.75 TO 1 CAC/L 1/5/26 | ||