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 of an ignition advance curve with a diagram of an oil relay.
| Identifier | ExFiles\Box 65\1\ scan0192 | |
| Date | 23th April 1926 guessed | |
| OIL RELAY MOVEMENT IGNITION ADVANCE CURVE SPRING E.{Mr Elliott - Chief Engineer} 75071 THIS CURVE SHOULD BE HELD TO ±1.5° MODIFIED FORM OF SPRINGING. I.E. HALF MOVEMENT OF SPRING. ANGULAR MOVEMENT LEVER A.{Mr Adams} ENGINE R.P.M. GOVERNOR R.P.M. 18 LBS. AT 24° CUT OFF BY WASHERS. | ||