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).
Requirements for a lightweight, simple magneto for the Goshawk engine as a secondary ignition system.
| Identifier | WestWitteringFiles\J\March1923\ Scan61 | |
| Date | 24th March 1923 | |
| TO BJ. FROM R.{Sir Henry Royce} C. to CJ. WOR.{Arthur Wormald - General Works Manager} C. to BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} ✓ C. to PN.{Mr Northey} DA{Bernard Day - Chassis Design} C. to E.{Mr Elliott - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} ORIGINAL RE. MAGNETO FOR GOSHAWK. E's memo. explains my view. I want the lightest magneto (1) to carry, and (2) to drive, because the magneto increases the tendency of the dynamo drive to rattle. (3) Also the magneto would be better if it did not make the control heavier and more liable to vibrate as the sleeve type does. (4) It is desirable for it to be a small machine for the above, and appearance, and the above reasons, and also it should be tilted over so that the tappet adjustment can at least be examined in case of a look or suspiciously wrong adjustment. Now as regards performance, (BY.{R.W. Bailey - Chief Engineer} quite right - I evidently meant Z.F.6. not Z.R.) I do not even desire so good slow running or high speed running, in fact I want it to be quite definitely the less desirable ignition than the battery, so that all reasonable people will run on the battery. It should not be necessary for one to write why, but one reason is that we can start and restart easier on the battery, often without the starter motor, and secondly no magneto is so satisfactorily governed as our battery ignition. Certainly while we can only fit one set of plugs one good and best ignition is necessary, the second one need only be good enough to get one home and repaired. Z.F.4. Bosch has run my pump engine very reliably as regards it's duty for many years, and is a light, small, neat, and inexpensive machine to fit; we ought to get this or it's equivalent. It is not necessary for us to test out a magneto for 12 months for our purpose and considering the reputation of good simple magnetos of the standard pattern (Bosch) of all good makes, should be good enough, and it would be sufficient for my purpose nearly, if the magneto had no advance, but it must be one that can be started by hand turning; this is O.K. with the Z.F.4. or 6., and with the 6 it does 1 1/4 crank revs., and the Goshawk is an engine that can be turned more quickly than the 40/50. We have been so used to two ignitions that I funk only one, especially depending on so many things as the battery. The Delage, my only helpless stop for 15 years, was ignition (unusual magneto) so the RR. high priced car should not be liable to be helpless for £15 to £25. I do not believe it need cost us more than £15 if cost and prices of magneto were normal. (1) | ||