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 effect of spark plug position on detonation for a No.2 Ramp Head in a Bentley single-cylinder test engine.
| Identifier | ExFiles\Box 133\2\ scan0094 | |
| Date | 5th January 1944 guessed | |
| BENTLEY SINGLE CYLINDER TESTS. SHEET 11 EFFECT OF PLUG POSITION ON DETONATION -- N°2 RAMP HEAD (SEE ALSO SHEET 12) EXHAUST SILENCED TO DETECT DETONATION N°2 RAMP HEAD (LEC 3871) INLET VALVE = 1.500" DIA NATURALLY ASPIRATED FUEL N°1 SHELL NORMAL VALVE TIMING COMPRESSION RATIO = 6.5 EXHAUST VALVE = 1.400" DIA AEROLITE PISTON Y-AXIS LEFT: AUDIBLE RANGE OF DETONATION (FEET.) Y-AXIS RIGHT (TOP): NECESSARY IGNITION ADVANCE Y-AXIS RIGHT (BOTTOM): B.M.E.P. (LBS/SQ. IN.) X-AXIS: RPM DATA LABELS: B.M.E.P. CURVE, COMMON TO ALL PLUG POSITIONS, (APPROX) PLUG IN SIDE POSITION TWO PLUGS (ONE IN NORMAL & ONE IN SIDE POSITION) PLUG IN NORMAL POSITION TWO PLUGS (SIDE POSITIONS) | ||