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).
Table of results from performance tests conducted on various magnetos.
| Identifier | ExFiles\Box 4\5\ 05-page348 | |
| Date | 2nd September 1924 | |
| X430 X.430 - TABLE OF RESULTS OF MAGNETO PERFORMANCES (To new schedule, dated 2.9.24) | Date of Test. | MAGNETO. Make. Type. No. | (1) Weight (lbs). | (3) Safety gap. (mms) | (4) Platinum gap. | (5) Available range Total. Auto. Hand. | (6) | (7) | (8) | (11) Utility test spark lengths (a) mms (b) mms (c) mms (d) mms | |---|---|---|---|---|---|---|---|---|---| | 23.11.25. | Watford EC6d 73970 | 13.4 | 8.5 | .012 | 63° - 63° | O.K. | O.K. | O.K. | 8.2 7.8 7.4 5.4 | | 10.11.25. | B.T.H PM6 356147 | 11.5 | 7.8 | .010 | 50° - 50° | " | " | " | 7.3 6.9 6.5 5.7 | | 31.11.25 | Lucas EBAS 156 | 12.25 | 8.5 | .013 | 60° - 60° | " | " | " | 8.0 7.3 6.9 6.2 | | 1.1.26. | Simms SR6L 127505 | 18.375 | 8.6 | .018 | 60° - 60° | " | " | occasional spark jump slip ring. | 8.0 7.7 7.6 7.0 | | 29.3.26 | Lucas ER6 50 | 13.69 | 8.8 | .013 | 58° - 58° | " | " | O.K. | not taken | | 19.4.26 | Scintilla. GN6 57927 | 13.8 | 12.8 | .012 | 63° - 63° | " | " | Safety gap too large. | Not taken | | 24.4.26 | Lucas ER6 51 | 13.625 | 8.5 | .013 | 59° - 59° | " | " | O.K. | Not taken | 2.9.24. | ||