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 exhaust back pressure curves versus R.P.M. for various silencer configurations.
| Identifier | ExFiles\Box 5a\5\ 05-page146 | |
| Date | 18th October 1938 guessed | |
| EXHAUST BACK PRESSURE CURVE ('JAPAN') ENGINE UNIT N.W.G.A. (5.25:1 COMPRESSION RATIO) 'H' LONG DURATION CAMSHAFT TWIN-CHOKE ZENITH CARB. SMALL BORE INS. PIPE ALL CURVES TAKEN WITH THREE DOWNTAKE PIPES & FRONT EXPANSION BOX TO V1125 AXIS LABELS: EXHAUST BACK PRESSURE (INCHES H2O) R.P.M CURVE LABELS: 25 H.P SILENCER, WITH FRONT EXTENSION PIPE REMOVED (SEE V1130) & SWAN-NECK STANDARD 25 H.P SILENCER SWAN-NECK REMOVED 25 H.P SILENCER WITH FRONT EXTENSION PIPE REMOVED & NO SWAN-NECK SHORT TYPE PH.II SILENCER WITH SWAN-NECK LONG TYPE PH.II SILENCER WITH SWAN-NECK BOXED TEXT: VALVE TIMING (COLD) I.O. 7.5° ATDC E.O. 43° BBDC I.C. 41.0° ABDC E.C. 4.5° ATDC | ||