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).
Letter to Mr. G.R.N. Minchin discussing ignition performance, dynamo output limits, and battery configurations.
| Identifier | ExFiles\Box 54\1\ Scan040 | |
| Date | 21th November 1925 | |
| X.46171? EFCL/T. 21st November, 1925. Mr. G.R.N. Minchin, 50, Grosvenor Gardens, London, S.W.1. X8780 X46178 Dear Mr. Minchin, Answering your three letters of the 9th, 10th and 16th inst.. Thank you for pointing out those other placed in the Instruction Book where the statements do not agree with our present recommendations, also for pointing out that coachbuilders are fitting an extra switch - this matter has been duly taken up. As you probably know, Mr. Hives is now back again. I took up with him the question of the second paragraph of your letter of the 16th with regard to a comparison of running on battery ignition only, with running on magneto and battery ignition, and he says that he does not agree that there is any difference in the running. That seems to be the general opinion, and as a matter of fact I myself had one of these cars on the road yesterday and though I do not pretend to be an expert in the matter, I certainly could not detect the slightest difference. He. says that if any difference is appreciable there is some wrong condition. As far as I can make out he also does not agree that the idle plugs would become sooted up. Now with regard to the output of the dynamo. I have given to the Test Dept. the figure of 14 amperes for the absolute maximum on peak output when the dynamo is warmed up, beyond which they may not pass a machine. At the same time I have never yet seen a machine which in the circumstances stated, gives more than 13 1/2 amperes, and have proved to my own satisfaction, from my own investigations, that with these dynamos correctly set to the production test, this output will not be exceeded in circumstances similar to those tried. I have added the modifying clause, because in the cases which I have observed there has been an Exide battery, or a sandwhich battery of half Exide and half P & R, so that I do not | ||