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).
Ignition coil improvements and variations for the Goshawk chassis, comparing different constructions and turn counts.
| Identifier | WestWitteringFiles\I\October1922\ Scan65 | |
| Date | 28th October 1923 | |
| EFC/T.28.10.23. -3- Contd. In perhaps 9 Goshawk chassis out of 10, driven in the ordinary way, it seems possible that the failure of the nature described would never occur. On the other hand it seems extremely difficult by anything we can do, having now made so many variations, and on all components of the ignition, to obtain consistently on successive chassis, an ignition which we can be certain will function correctly under every possible condition. It is suggested that an additional ¼" or ½" to the length of the coil might make the difference required. EFC. Later. A coil of improved Goshawk construction, but with 16000 turns has now been tried and appears to be an improvement though still is not as good as the 40/50 coil with the 10" length of ballast. It will be remembered that the reason for departing from the 40/50 coil on the Goshawk ignition and using a B coil which has 300 primary turns in place of 360, was to accommodate high speed running without misfiring, the amount of ballast resistance being relatively less important in this case. Now that coils have been made improved in other ways and this high speed effect possibly be eliminated on the 40/50, it may be desirable to revert to the larger number of primary turns. EFC. | ||