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).
Specifications for an ignition distributor, platinum point gap, and contact breaker timing.
| Identifier | ExFiles\Box 49\5\ Scan164 | |
| Date | 19th July 1922 guessed | |
| -2- Contd. (4) Length of h.t. safety gap (inches) :- .394 " " " " (mm) :- 10.0. (5) Distributor :- Total pitch :- 1.44" Conductor width :- .975" Brush width :- .20" Position of brush at break (advanced) :- 18° " " " " " (retarded) :- 66° (6) Platinum point gap :- .010" and .012" Contact breaker timing :- Table 1: Make. Break. A. {Mr Adams} -81.5 +78° R. {Sir Henry Royce} -19° +139° Table 2: Retarded Advanced Make. -19° -80° Break. 138° 76° Make. 161° 97° Break 320° 260° Range :- 62° Make ratio :- .882 Note: The contact breaker gap was unequal on the two sides of the machine. | ||