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).
Comparative tests of ignition system components including platinum and tungsten points.
| Identifier | ExFiles\Box 35\6\ scan 191 | |
| Date | 20th August 1926 | |
| Contd. -2- EFCL/T20.8.26. We have in progress a systemmatic set of comparative tests of (a) Platinum, (b) English tungsten (c) U.S.A. tungsten points, working on - (1) Our present standard ignition system. (2) Our ignition system but with finer primary coil. (3) Our ignition system but with finer primary coil and double ballast resistance. Each of the nine combinations is undergoing a bench run equivalent to 10,000 miles on the road, and all except those under (3) (double ballast) will be completed by Thursday, Sept. 2nd. In these comparisons the Remy contact breaker is used when using U.S.A. points, but only that item, i.e. the Remy condenser is not used but a standard RR. condenser adapted to the make and break, so that the whole of the rest of the system is our own. So far as these tests have gone to date they appear to be shewing up very definitely, though we cannot yet assert it was conclusively proved, that it is neither coils nor condensers that are responsible for poor contact point results, but the material of the points. The U.S.A. material is apparently superior not only to the British tungsten but also to the standard platinum which we are using. We are sending comparative examples of U.S.A. and English tungsten points to our English suppliers with a request for their explanation of the matter. We are also sending new samples of each kind for analyses to Messrs. Johnson Matthey, and the results of these we hope may be available in about a week's time. It would appear that the insulation of the Bosch condenser has been improved, because we recollect making | ||