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).
New ignition scheme for the Boshawk, using one big and one miniature plug, and a three-position switch.
| Identifier | ExFiles\Box 45\4\ Scan353 | |
| Date | 19th January 1923 | |
| Extract from. X4081 R6/M19.1.23. RE IGNITION X.3485. X.4560. X.4091. Now in the case of the Boshawk, the cylinder head is so small that 2 ordinary sized plugs cannot be fitted, but after Hs.{Lord Ernest Hives - Chair} had fitted the miniature Bosch plugs it occurred to me that we might possibly fit one big plug and one miniature plug. This is the scheme we want to get moving as it will enable us to send out all the cars with both ignitions wired up and running. X.4081 X.1413. This scheme can work with the present locked X.4081 ignition switch as already arranged, but would be further improved by the addition of a small switch as suggested in a recent memo. This switch is intended to permit both ignitions being run together, or each separately to test that each system is in working order, so that it will have 3 positions, but to avoid confusion it will not be capable of stopping all the ignitions, so that in one position it will do nothing when the magneto alone will be working. In the next position it will do nothing to the magneto but make battery ignition, in which case both ignitions would be working. In the third position it will earth the magneto and continue to make the battery ignition, in which case battery ignition only will be working. | ||