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).
Observations of various ignition contact point samples, comparing platinum and tungsten types.
| Identifier | ExFiles\Box 61b\4\ scan0127 | |
| Date | 31th December 1926 | |
| To OY. from EFC. c. R.{Sir Henry Royce} c. BY.{R.W. Bailey - Chief Engineer} EFC5/T31.12.26. IGNITION CONTACT POINTS. X.4284/75. Further to our report EFC2/T24.12.26 and with particular and further reference to Mr. Olley's note OY2/E.{Mr Elliott - Chief Engineer} 61126, our observations on the sample points sent by OY. are as follows :- Sample in Envelope I. These were platinum, run 600 miles presumably with RR. standard ignition. The characteristic effect of these points is that of the presence of a small amount of oil vapour. The characteristic effect when no oil vapour is present is that of the production of an elevation on the lever point with the corresponding depression on the screw point, but this does not occur so badly as to necessitate attention to the points until after about 5,000 miles. It will be remembered that in our report EFC2/T24.12.26 all the samples described (with slight exceptions) have run 10,000 miles on the bench. Sample contained in Envelope II. The effect on these points is very similar to effects which we have had running tungsten points on our own ignition on the bench. Therefore it is, as we should have expected, under conditions as described by OY. Though not stated, we presume this was run on our own contact breaker, because we get decidedly better results than this by running tungsten points on the Delco-Remy contact breaker with otherwise our own ignition system. | ||