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).
Discussion comparing battery and magneto ignition systems and their performance in engines like the 'Falcon' and 'Condor'.
| Identifier | ExFiles\Box 37\1\ scan 030 | |
| Date | 4th May 1918 | |
| Contd. from R.{Sir Henry Royce} -2- RB{R. Bowen}/G4.5.18. or a small current running, and large short-circuit current, according to the proportions the ratio of the balance resistance. In fact, it appears to me that the balance resistance would have very little effect at the higher speeds, and should be made as high as possible, and as absolutely non-inductive as possible. X.2410 We are anxious for you to let us know if any of the battery ignitions are as good as the magneto ignition, when the explosive mixtures are somewhat away from the best, both as regards over-strong, and especially weak mixtures, and when the distribution is imperfect, but more especially as regards the weak mixture. It will be noticed from Mr. Platford's memo of the 1st May (EP{G. Eric Platford - Chief Quality Engineer}6/F1518) re "Falcons" that these, and we have no doubt many other engines, are considerably over-run in cases of fast dives, and it would appear that the ignition apparatus must be capable of a considerable advance in speed above normal, without failing. In the case of the "Falcon" this appears to be as much as 50% which would bring the ignition required for the "Condor" up to an engine speed of say, 2500 revs., which equals 15,000 ignitions per minute. I understand you have already achieved 10,000 ignitions per minute, when attempting to obtain at least 6,000, so that very little alteration would appear necessary. With regard to the "Liberty" and other types of ignitions, it would appear that a safety gap is really needed, (CONTD) | ||