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 comparing engine detonation performance between a No. 2 Ramp head and a standard Bentley head during single cylinder tests.
| Identifier | ExFiles\Box 133\2\ scan0093 | |
| Date | 5th January 1944 guessed | |
| BENTLEY SINGLE CYLINDER TESTS SHEET 10 DETONATION COMPARISON - N°2 RAMP & STD. BENTLEY HEADS EXHAUST SILENCED TO DETECT DETONATION NATURALLY ASPIRATED AEROLITE PISTON ZENITH TRIPLE DIFFUSER CARBURETTOR (32% CHOKE) FUEL - N°1 SHELL COMPRESSION RATIO: N°2 RAMP - 6.5, STD. BENTLEY - 6.4 AUDIBLE RANGE OF DETONATION (FEET) B.M.E.P. (LBS/SQ. IN.) NECESSARY IGNITION ADVANCE RPM TIMED TO GIVE MAXIMUM POWER AT 3000 RPM DITTO, BUT WITH OVERLAP LIMITED TO 12° STD. BENTLEY HEAD & STD. VALVE TIMING. | ||