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).
Timing specifications for a Watford E06d Magneto No. 73972.
| Identifier | ExFiles\Box 48\2\ Scan434 | |
| Date | 11th March 1926 | |
| x8796 11.3.26. WATFORD E06d. MAGNETO NO.73972. ------------------------------ Timing of contact breaker in the retard and advance position in relation to the maximum flux position of armature. --------- Fully advanced. | Make | -65º | | Break | 86º | | Make | 115º | | Break | 267º | Range = 17º Make ratio = .838 Fully retarded. | Make | -47º | | Break | 103º | | Make | 132º | | Break | 233º | Actual range of cam lever = 62º EFC. {E. Fowler Clarke - Electrical Engineer} 87 | ||