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).
Comparative ignition coil tests on chassis 7-GII.
| Identifier | ExFiles\Box 45\4\ Scan271 | |
| Date | 8th April 1924 | |
| 8.4.24. COIL TEST ON 7-GII. Tested on London Road. Water boiling. 1st test. High speed. 2nd. " Low speed full throttle.10 M.P.H. 3rd. " Starting (Engine). Spark gap adjusted for best result. Standard coil. taken from stock. No.4383. O.K. at high speed. 10 M.P.H. .106" Gap. Misses badly, starting very bad, necessary to change down, would not pick up on top gear. .090" - .080" - .070". same as above. .050". Misses badly. Starting bad, but picks up on top gear. .040" Ditto. .030" Misses, starting poor but picks up on top gear. .020" O.K. TR.{Capt. F. W. Turner - Finance}2. Coil. O.K. at high speed. 10 M.P.H. .106" gap. Was very good for a time, then started to miss badly; starting very poor. .090"-.080" Missing badly. Starting poor. .075" Missing slightly. " " " " .060" Very slight miss. Starting fair. .050" O.K. O.K. TR.{Capt. F. W. Turner - Finance}3. Coil. O.K. at high speed. 10 M.P.H. .106 gap. Was very good for a time then started to miss. .090 & .080". Missing. Starting poor. .075" Very slight miss. Starting good. .060" O.K. O.K. F.A. Gibson. | ||