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 showing the engine power curve increase due to using larger chokes in the carburettor.
| Identifier | WestWitteringFiles\Q\2-July1927-September1927\ 121 | |
| Date | 13th April 1927 | |
| STANDARD PHANTOM POWER CURVE (SHEWING INCREASE DUE TO LARGER CHOKES IN CARBURETTOR) ENGINE No RE 25. COMPRESSION RATIO = 4.12 to 1. STANDARD INDUCTION PIPE. FIXED EXHAUST SYSTEM (WITH SILENCER) CURVES CORRECTED TO N.T.P. CARBURETTOR HAVING 1.250 DIA: H.S. & .830 DIA L.S. CHOKES. AIR PORTS LARGER IN SAME PROPORTION. INLET AREA 126% GREATER THAN STD. AIR VALVE PISTON REMOVED (LARGER CHOKES) STANDARD CARB. DEPRESSION IN INDn PIPES - STD CARB. LARGER CHOKES. AIR VALVE REMOVED. BRAKE HORSE POWER. R.P.M. OF ENGINE. IND.n PIPE DEPN. (INS OF Hg) | ||