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).
Procedure for conducting utility tests on a magneto under various conditions.
| Identifier | ExFiles\Box 4\5\ 05-page137 | |
| Date | 28th January 1921 guessed | |
| -3- Contd. (13) The magneto shall now be subjected to utility tests, i.e. tests to find out its capability of producing a spark under adverse, e.g. leaky, sparking plug conditions. For this purpose two Remy 12 cylinder coils shall be used and connected across one of the six gaps in the following sequence :- (a) Nothing connected across. (b) The secondaries of the two Remy coils in series connected across, one Remy primary to be short-circuited. (c) Ditto, but with both Remy primaries short-circuited. (d) The secondary of one Remy coil only connected across with its primary short-circuited. The magneto shall again be run at 1500 R.P.M. and the greatest length of gap possible under the varying conditions (a), (b), (c) and (d) obtained for one gap of the six, across which the secondary coils are connected. Lengths of H.T. leads assumed always to be 2 feet, and timing lever central. (14) A range of advance and retard of 34° shall now be arrived at in the following manner :- The stop limiting the travel on the contact breaker advance and retard lever shall be removed, after having made the necessary marks indicating the makers limits of range. The magneto shall be connected by H.T. leads to the necessary spark gaps set at 5.5 mm. In the first instance, the machine shall be driven at 3500 R.P.M. and the | ||