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).
Controls and synchronization for magneto and battery ignition systems on 'Falcon' and 'Eagle' engines.
| Identifier | WestWitteringFiles\A\October1917\ Scan5 | |
| Date | 15th October 1917 | |
| To Bv. from E.{Mr Elliott - Chief Engineer} c. to FP.{F. Potts} c. to WH. [STAMP: ORIGINAL] West WitteringHenry Royce's home town [STAMP: RECEIVED 17 OCT 1917] Oct. 15th 1917. X. 3173 X 3191 Re - Controls for Magneto & Remy Ignition E5/W151017. Re your Byl/G131017 please note scheme LeC.862 is arranged so that the battery ignition has a range of 44° on the crankshaft. This in combination with a 35° advanced position of firing point as used on the "Falcon" engines gives 9° retard which is intended to be used for starting by hand on electric motor. When ignition control is fully advanced the magneto and battery should synchronise. When fully retarded they do not synchronise. I do not know what range of movement you have on the Watford magnetos and should be glad if you would send this information. Your drawings indicate that it is rather less than that which obtained on the Bosch Magnetos. I have however taken the lever lengths from your control scheme for the "Eagle" and assumed that the control countershaft carried on the magneto bracket has an angular movement of 90°. The general scheme of interconnection of battery and magneto ignition is as required by Mr. Royce and used on the R.R. car. The battery has a longer range to give a suitable retarded position for starting and both ignitions synchronise at full advance. We understand rather from Derby that once the engine is started, the ignition control is set to full advance and left there. [Handwritten note:] This does not mean that we are cancelling the hand starting magneto. this latter is retained. as a means of obtaining a start if battery ignition is run down. | ||