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 ignition governor advance curves for a 25 HP engine.
| Identifier | ExFiles\Box 3\4\ 04-page252 | |
| Date | 31th March 1933 guessed | |
| 25 H.P. IGNITION GOVERNOR - ADVANCE CURVES ENGINE DOS: C.S. (CAST IRON TURBULENT HD.{Mr Hayward/Mr Huddy} 5.3:1 C.R.) SINGLE S.U. CARBURETTER (1 3/16 DIA. THROTTLE) CURVE ① IDEAL USE (MINIMUM ADVANCE FOR MAXIMUM POWER) ② ACTUAL ADVANCE (STANDARD WTS. & SPRINGS) ⑦ SPRINGS 9 COILS 16 SWG LEAD WTS. SPRINGS SET TO JUST RETURN WTS (23° AUTO ADV.) IGNITION ADVANCE (DEGREES BEFORE T.D.C°.) R.P.M. 5% DROP ADVANCED 5% DROP RETARD | ||