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 distributor, contact breaker timing, and platinum point gap.
| Identifier | ExFiles\Box 48\2\ Scan076 | |
| Date | 21th March 1924 guessed | |
| -2- Contd. (4) Length of h.t. safety gap (inches) :- .465" " " " " (mm) :- 11.8 (5) Distributor :- Total pitch :- .940" Conductor width :- .195" (Handwritten: Brushes in place of the usual segments) Brush width :- .460" (Handwritten: Rotating Segments.) (Handwritten: Advanced auto :- .10") Position of brush at break (advanced) :- .27" (Hand) " " " " " (retarded) :- .39" (Handwritten: Note:- Full advance calculated from Hand advance.) (6) Platinum point gap :- .013" Contact breaker timing :- (Handwritten: 55°) Table 1: Make. Break. A. {Mr Adams} 16° 94° R. {Sir Henry Royce} 69° 146.5 Table 2: Retarded Advanced. Make. 68.0° 15.5° Break. 147° 94.5° Make. 250° 196.5° BREAK 326° 273.5° Range :- 53° Make ratio :- .432 (Handwritten: N.B. Automatic Advance subtracted) | ||