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).
Blueprint graph comparing ignition advance curves for a Lighter Phantom engine, showing present, required and proposed curves.
| Identifier | ExFiles\Box 65\1\ scan0201 | |
| Date | 17th May 1927 guessed | |
| IGNITION ADVANCE FOR LIGHTER PHANTOM TO LEC 2230 (BOTH IGNITIONS BEING SYNCHRONISED) Top Chart (A): DEGREES ADVANCE ON FLYWHEEL PRESENT COMPROMISE REQ'D CURVE 13° M&B 1° M M 1° 13° B M 1° B 23° Bottom Chart (B): DEGREES ADVANCE ON FLYWHEEL THIS CURVE IS BETTER FOR ANTI DETONATING REQ'D CURVE PROPOSED 10° M&B 2° M&B M 2° 8° B M 2° 16° B R.P.M. OF ENGINE Y-Axis values: 10°, 20°, 30°, 40° X-Axis values: 500, 1000, 1500, 2000, 2500 | ||