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).
The ignition system for the Goshawk engine, recommending a primary battery ignition with a magneto as a backup.
| Identifier | ExFiles\Box 54\5\ Scan236 | |
| Date | 15th February 1923 | |
| X3485 To Hs. {Lord Ernest Hives - Chair} from R. {Sir Henry Royce} c. to CJ. BJ. Wor. {Arthur Wormald - General Works Manager} c. to Ev. {Ivan Evernden - coachwork} E. {Mr Elliott - Chief Engineer} EP. {G. Eric Platford - Chief Quality Engineer} RI/M15.2.23. X.3551. RE GOSHAWK IGNITION X.3485. For the present I recommend that we arrange everything possible so that our battery ignition shall be the real ignition for this engine. Until developments suggest a change I think that the cyl. head should be fitted with one present standard size plug per cyl. and that no hurried attempt should be made to introduce 2 plugs into the head, either small ones, or one large, and one small, as it may result in failure of the castings, and we think for so small an engine 6 plugs are enough to provide and maintain clean and free from pre-ignition troubles. That we fit to all chassis as soon as convenient a magneto, running, timed, and wired, in case of a failure of the battery, car wiring, or battery ignition. It will be agreed that the car cannot go better for a second ignition for such small cyls. and it is desirable on account of luffing up that the ignition in general use shall be governed. The type and size of magneto should I think be equivalent to the Z.R. Bosch, for the sake of lightness in weight and drive. It is not necessary for this magneto to give a spark at very slow speeds to have a tremendous annhular advance as in the case of the present Watford used on the 40/50. Such an equipment should not add to the cost of the Goshawk more than £20 and should be a great recommendation to a buyer to know that if he is out at night, far in the country, or abroad, he ought not to be stopped more than 5 minutes (not even a lady driver) though ignition troubles, in fact the operation of changing to the spare ignition would not be as great as changing a spare wheel. From my own point of view the Watford magneto people would make us such a magneto, and it would be if I was a buyer, a great inducement for me to purchase a car having a reserve ignition. R. {Sir Henry Royce} P.S. Will CJ. please note that I want it tobe agreed that the magneto shall be fitted as above, as standard, without extra charge. R. {Sir Henry Royce} | ||