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 magneto performance including timing lever positions and operational limits.
| Identifier | ExFiles\Box 57\2\ Scan198 | |
| Date | 3rd April 1928 guessed | |
| -3- Contd. A.{Mr Adams} 250 r.p.m. for the fully advanced position of the timing lever. B. 200 r.p.m. for the central position. C. 180 r.p.m. for the fully retarded position. Note:- The minimum regular sparking speed can be taken to be that speed at which 100 consecutive sparks, without missing, are given by the magneto at some time within a period not greater than 5 minutes. (8) The timing of the magneto break shall not be varied more than +- 3° by altering the primary point gap +- .004" from normal respectively. (9) A reasonable silence of operation of the magneto is essential. (10) The direction of rotation of the magneto shall be clockwise, looking on the driving end. (11) The tangential force, measured at lever pin radius, necessary to advance or retard the contact breaker shall not exceed 2 lbs. weight. EFC. | ||