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 20HP engine showing power increase due to valve lift, compression, larger valves, and lower induction pipe depression.
| Identifier | ExFiles\Box 5a\5\ 05-page054 | |
| Date | 31th March 1927 guessed | |
| .20.HP POWER INCREASE DUE TO LONG DURATION OF VALVE LIFT. HIGHER COMPRESSION RATIO, LARGER VALVES, AND LOWER INDUCTION PIPE DEPRESSION. ENGINE No H-GE COMPRESSION RATIO - 5.3 TO 1 LARGE VALVES (1.40" DIA) TWO ZENITH TRIPLE DIFFUSER TYPE CARBS SPECIAL LONG DURATION CAMSHAFTS. OPEN EXHAUST THE DOTTED CURVE REFERS TO STANDARD ENGINE BRAKE HORSE POWER PETROL CONSUMPTION B.H.P B.M.E.P R.P.M. OF ENGINE PETROL CONSUMPTION (PINTS/BHP/HR) B.M.E.P. (LBS. PER SQ. IN) | ||