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 ignition governor curves for a 25/30 deturbulated head.
| Identifier | ExFiles\Box 103\4\ scan0182 | |
| Date | 16th May 1936 | |
| 25/30 IGNITION GOVERNOR CURVES. DETURBULATED HEAD. TEST CARRIED OUT WITH SHELL NO: 1. AND STANDARD CHASSIS EXHAUST SILENCER. E.60660 HEAD DETURBULATED TO Lec. 5002 (5.86:1 COMP: RATIO) STD: VALVES 1.4 DIA: INLET 1.225 DIA: EXHAUST STD: STROMBERG IND'N SYSTEM. ① IDEAL LINE (MINIMUM ADVANCE FOR MAX: POWER.) ② LINE TO CUT OUT DETONATIONS. ③ 2% POWER DROP BY RETARDING. ④ PROPOSED LINE AS GIVEN BY AUTOMATIC OF SPECIALLY PREPARED GOVERNOR. Y-AXIS: SPARK POSITION FLYWHEEL ° B.T.D.C. X-AXIS: ENGINE R.P.M. | ||