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).
Ignition coil polarity and distributor adjustments for improved engine firing.
| Identifier | WestWitteringFiles\D\October1919\ Scan31 | |
| Date | 24th October 1919 | |
| Contd. -3- EFC10/T24.10.19. regularly. This can be done as follows:- (1) The direction of current through the primary coil must be such as to produce a high tension discharge of a certain polarity at the plug points as it is very definitely proved both on chassis and bench tests that polarity has an effect on the tendency to discharge. It is curious, however, that the direction of the current which gives the most regular firing on the bench is not the same as the direction of current giving the most regular firing on the engine. All coils we have tried of different makes shew this effect of polarity on the bench. We have asked for the alteration to direction of current in the primary to be carried out on all possible existing chasses and to be made standard for the future. This is being done by Messrs. Platford and Bailey, and only involves a change of connections on the top of the coil which can be effected quite easily in one minute. (2) The rotor and high tension points of the distributor must be carefully adjusted; the periphery of the rotor platinum must be quite concentric with the axis of rotation and the rotor must be so set that the break takes place when the leading end of the rotor periphery is well over the stationary contact point. Further, the spark gaps and the distributor must be set down to the smallest value consistent with no actual contact with the limits obtainable on production in this apparatus. It is, therefore, seen that every item of the high tension distributor must be very accurately made. Contd. | ||