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, including h.t. safety gap, platinum point gap, and contact breaker timing.
| Identifier | ExFiles\Box 48\2\ Scan067 | |
| Date | 13th July 1923 guessed | |
| -2- Contd. (4) Length of h.t. safety gap (inches) :- .453 " " " " " (mm) :- 11.5 (5) Distributor :- Total pitch :- .960" Conductor width :- .195" Brushes in place of the usual segments. Brush width :- .460. Rotating segment. Position of brush at break (advanced) :- (Auto) .170 " " " " " :- (Hand) .350" " " " " " (retarded) :- .460" Note :- Hand advance only observed. Full advance, i.e. including auto. advance, calculated from hand advance. (6) Platinum point gap :- .012" Contact breaker timing :- (Table 1) Make. Break. A. {Mr Adams} 13° 96° B. 65.5° 149° (Including auto. advance) (Table 2) Retarded Advanced. Make. 66° 14° Break. 149° 96° Make. 245° 192° Break. 329° 276° Note :- Full advance calculated from hand advance. Range :- 53° Make ratio :- .463 | ||