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).
Report comparing the performance of platinum versus tungsten interrupter points, coils, and condensers.
| Identifier | ExFiles\Box 35\6\ scan 125 | |
| Date | 11th June 1926 | |
| Oy2-E-61126. *X2894 June 11th 1926. Mr. Basil Johnson, Rolls-Royce Ltd., London, England. (Copy for attention of Mr. F.H. Royce " " " " Works Committee " " " " Mr. Nadin. X4652 X4654 X2894 Dear Sir: Re Platinum interrupter points, coils and condensers - Section 5150. 1. We find the platinum points on the battery ignition head to be inferior to tungsten in actual performance in the U.S. 2. We also have reason to believe that the type of coil with an almost continuous iron circuit is more gentle in its treatment of the interrupter points than the present English coil. 3. The English condensers appear to partially break down in the dielectric either in storage or in shipment across the Atlantic. 1. Interrupter Points. a.{Mr Adams} The platinum points on 12-MC we found required bedding every 1000 miles or so. At 5000 miles we had to install a new set. These ran 600 miles and are in attached envelope marked I. b. Tungsten points were put in with an American Bosch coil, 12 volt, as shown in print A-2823 attached. These ran 1000 miles and were then inspected. The tungsten points shewed practically no signs of use beyond slight discoloration round the edges. c. Because we had changed two things at once we decided to put back the English coil to make a fair test. Tungsten contacts have since run 8000 miles and are in envelope marked II. It will be seen that, though pitted, their condition after 8000 miles is comparable with the condition of the platinum after 600 miles. d.{John DeLooze - Company Secretary} Envelope III contains platinum points taken from 61-LC for replacement at 1165 miles. Contd. | ||