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).
The performance and testing of ignition coils, condensers, and platinum points.
| Identifier | ExFiles\Box 35\6\ scan 177 | |
| Date | 11th June 1926 | |
| Oy2-E-61126 -2- June 11, 1926. 1. d.{John DeLooze - Company Secretary} Envelope III contains platinum points taken from 61-LC for replacement at 1165 miles. 2. Coils. On American Bosch ignitions it is usual for contacts to run 10,000 miles without attention, and 25,000 miles without replacement. The Bosch coil like the Delco and other modern American coils has an almost continuous iron circuit, the primary wound on the outside of the secondary and no ballast resistance. The heat dissipation from the primary is sufficient to limit the temperature of the coil to a reasonable figure even with the engine at a standstill. We think that perhaps the long iron circuit avoids rapid alternations in the primary at break which may damage the the contacts. We shall be pleased to send American Bosch or Delco coils for test, if you desire them. 3. On five 20 hp. condensers taken from Maintenance Dept. stock for replacement in Service, we find a dielectric resistance varying between 1/4 and 7 megohms. Six American Bosch condensers similarly tested read 40 megohms to infinity. Yours very truly, (Sgd) Maurice Olley. MO/E | ||