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 of magneto performances.
| Identifier | ExFiles\Box 4\5\ 05-page346 | |
| Date | 4th January 1926 | |
| X.430. X.430. TABLE OF RESULTS OF MAGNETO PERFORMANCES 4.1.26. (To new schedule dated 29.8.24.) Date of Test. | MAGNETO Make. | MAGNETO Type. | No. | (1) Weight (lbs) | (3) Safety gap. (MM.) | (4) Platinum gap. (") | (5) Available range Total. | (5) Available range Auto. | (5) Available range Hand | (6) | (7) | (8) | (11) Utility test spark lengths (mm) (a) | (11) Utility test spark lengths (mm) (b) | (11) Utility test spark lengths (mm) (c) | (11) Utility test spark lengths (mm) (d) 20.8.24. | B.T.H. | CE6 | 406821 | 14.375 | 8.6 | .015" | 22º | 0º | 22º | O.K. | O.K. | O.K. | 7.7 | 5.0 | 4.8 | 3.1 24.9.24. | Watford. | EO6 | 73957 | 12.5 | 8.5 | .012" | 28.5º | 0º | 28.5 | " | " | " | 7.9 | 6.5 | 6.0 | 3.7 25.9.24. | R.{Sir Henry Royce} Bosch. | ZR6 | 2571555 | 18.25 | 10.2 | .012" | 37º | 0º | 37º | " | " | Safety gap too large. | 9.3 | 7.7 | 7.3 | 5.3 26.3.25. | Watford | EO6d. | 73972 | 12.5 | 8.5 | .011" | 62º | - | 62º | " | O.K. | O.K. | 8.5 | 7.9 | 7.7 | 5.4 2.11.25. | B.T.H. | PM6 | 356071 | 11.5 | 7.8 | .010" | 50º | - | 50º | " | " | " | 7.2 | 7.0 | 6.8 | 5.6 10.11.25. | " | " | 356147 | 11.5 | 7.8 | .010" | 50º | - | 50º | " | " | " | 7.3 | 6.9 | 6.5 | 5.7 23.11.25 | Watford. | EO6d | 73970 | 13.4 | 8.5 | .012" | 63º | - | 63º | " | " | " | 8.2 | 7.8 | 7.4 | 5.4 | ||