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).
Test results and data for contact breaker timing and primary point gap settings.
| Identifier | ExFiles\Box 65\3\ scan0066 | |
| Date | 23th August 1927 guessed | |
| -6- (14) Secondary milliamps :- Maximum :- 18.5 Minimum :- 5.7 (15) Primary point gap after previous tests :- .010" Primary point gap .006" Contact breaker timing. | | Make. | Break. | |---|---|---| | A | -9° | 94° | | R | 50° | 153° | | | Retard. | Advance. | |---|---|---| | Make. | 51° | -8° | | Break. | 153° | 94° | | Make. | 229° | 170° | | Break. | 333° | 274° | Make ratio :- .573 Primary point gap :- .014" Contact breaker timing. | | Make. | Break. | |---|---|---| | A | -6° | 91° | | R | 53° | 150° | | | Retard. | Advance. | |---|---|---| | Make. | 54° | -5° | | Break. | 150° | 91° | | Make | 232° | 173° | | Break | 330° | 271° | Make ratio:- .538 Variation in Break 1½° (max) | ||