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 power variation with the size of the carburetor choke for a Phantom engine.
| Identifier | ExFiles\Box 66a\1\ scan0237 | |
| Date | 20th June 1928 guessed | |
| Power Variation with Size of Choke, (Phantom). ENGINE No H.U.25. WEIR TYPE INDn PIPE (Sc. 980). STD. TWIN EXHAUST MANIFOLDS. VERTICAL CLAUDEL-HOBSON CARBURETTOR. COMPRESSION RATIO - 4.25. STANDARD CAMSHAFT. TEST BED SILENCER. CONTINUOUS LINE CURVES :- CHOKE = 1.530" DIA. AREA AT RESTRICTION = 1.532 SQ. INS. DOTTED LINE CURVES :- CHOKE = 1.800" DIA. AREA AT RESTRICTION = 2.238 SQ. INS. Y-AXIS LEFT: BRAKE HORSE POWER. Y-AXIS RIGHT: INDUCTION DEPRESSION (INS. MERCURY). X-AXIS: R.P.M. OF ENGINE. GRAPH LABELS: B.H.P STD. CARB. DEPRESSION AT CHOKE DEPRESSION IN INDUCTION PIPE. | ||