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 test of spark length for magneto and battery ignition systems under different leakage conditions.
| Identifier | ExFiles\Box 4\5\ 05-page123 | |
| Date | 21th December 1920 | |
| X.2375. X.3128. COMPARATIVE SPARKING OF PAT GMD K.6 MAGNETO AND R.R. STANDARD BATTERY IGNITION ON UTILITY TEST. | Nature of leakage. | Maximum spark length (mm) for regular firing on one of six gaps fed in sequence from the distributor and across which is placed a feebly conducting path as below. | Maximum spark length (mm) for regular firing on one gap, fed direct from the coil and across which is placed a feebly conducting path as below :- | |---|---|---| | | Magneto. | Ignition coil. | Ignition coil. | | A.{Mr Adams} None. | 5.0 | 8.5 | 9.5 | | B. Secondaries of two Remy 12 cyl. 6 volt ignition coils in series, one primary closed. | 4.75 | 6.0 | --- | | C. Ditto, both primaries closed. | 4.25 | 2.0 | 4.5 | | D.{John DeLooze - Company Secretary} Secondary of one Remy 12 cyl. 6 volt ignition coil, primary closed. | 3.5 | 1.5 | 2.0 | Note:- The Utility Test consists in placing a feebly conducting path across one gap to represent the condition of a leaky sparking-plug. | ||