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).
Instruction sheet detailing observations on induced sparking across ignition system gaps under different conditions.
| Identifier | ExFiles\Box 52\1\ Scan051 | |
| Date | 29th June 1920 | |
| RR 228 (100 BKS) [AH97-29-6-20.] MP 224398 ROLLS-ROYCE LTD. INSTRUCTIONS. 19 To Order No. (2) Customer's No. of 5 minutes, would avoid the passage to earth of induced sparks from the terminal of the spare (13TH) wire. This was found to be .119" With the Battery ignition wires sparking and the magneto switched off this gap for the same conditions was .114" Both ignitions were then switched on together and the induced sparking observed on the gap (this being set to the previous max value ie .119"). It was observed that sparks would jump this gap approx once every 20 secs the maximum gap to avoid, during 5 mins, a spark over being increased to .129" Signed contd This Sheet must be filed on completion of the work. | ||