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).
Continued discussion on the timing and design of magnetos and distributors for a six-cylinder engine.
| Identifier | ExFiles\Box 48\2\ Scan445 | |
| Date | 29th March 1926 | |
| -2- EFCL/T29.3.26. Contd. next make. It is not, therefore, when the magneto is retarded, necessary for the brush to remain in contact with the segment for the whole time till the next make, and so to a large extent the question of the range of the magneto does not enter into this consideration. Observations which we have made from time to time of the distributors of various magnetos have shown that in a good many cases the "backward overlap at retard" of the brush on the segment is negative, even with magnetos with a good deal smaller range(than 60°). We agree that the insulation distance cannot be reduced. We have thoroughly considered the whole matter of the timing of a rotating armature magneto (with and without sleeves) and of that of a six-cylinder distributor to operate in conjunction with it, and we attach two copies of the notes which we have made up as a result of this consideration. In these notes, it is shown that it is quite possible reasonably to arrange the timing of the magneto and its distributor for the 61° range, with suitably long periods of break, without increasing the present Watford size of the distributor or reducing the insulation distance. No doubt it may be interesting to the Watford Magneto Co. to peruse these notes and possibly they may consider making up a magneto experimentally with approximately this re-arranged | ||