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 for contact breaker timing and primary point gap measurements.
| Identifier | ExFiles\Box 43\4\ Scan132 | |
| Date | 19th July 1928 guessed | |
| -5- Contd. (14) Secondary milliamps :- Maximum :- 5.1 Minimum :- 2.9 (15) Primary point gap after previous tests :- .010" Primary point gap .016" Contact breaker timing. Make. Break. ADVANCE RETARD A 6.5° 48.5° Make. 6° 38° R 38.5° 77.5° Break. 49° 78° Make. 97° 129° Break. 138° 167° Make ratio:- .450 Primary point gap :- .008" Contact breaker timing. Make. Break. ADVANCE RETARD A 1° 52° Make. 0° 32° R 33° 81° Break. 52° 81° Make. 92° 124° Break. 142° 171° Make ratio:- .550 Average variation in Break :- 2° | ||