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 power output (B.HP) versus R.P.M. for a 20 HP engine at standard and increased compression ratios.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan083 | |
| Date | 1st May 1926 | |
| 20 H.P. ENGINE - POWER OUTPUT WITH INCREASED COMPRESSION RATIO CORRECTED FOR BAR 760 MM. 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 ael / 1/5/26 Y-Axis: 60, 50, 40, 30, 20, 10 X-Axis: 500, 1000, 1500, 2000, 2500, 3000 | ||