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).
Outlining the requirements for a battery ignition system on the Goshawk engine.
| Identifier | ExFiles\Box 37\1\ scan 134 | |
| Date | 14th February 1922 | |
| TO E.C. from R.{Sir Henry Royce} x3199 R6/14.2.22. c. to W. c. to Or. c. to Hy.{Tom Haldenby - Plant Engineer} ✓ c. to HS.{Lord Ernest Hives - Chair} c. to W. c. to Mr. Brock. X3480 RE BATTERY IGNITION. x3199 (1) Our battery ignition must be quite safe to run the engine up to 3300 revs. without misfiring, with plugs set at .025 or whatever standard is fixed for the Goshawk with the full compression used in the engine. (2) The ballast resistance must be so that with half the maximum volts of the battery, say 6 or 7, the ignition will fire the engine during starting operations when the voltage may fall to this amount. We do not mind if it is cut down until the current on short circuit is 3 or even 4 amperes. (3) It is fortunate in the arrangement we have adopted, that the losses in the starter cable do not affect the voltage of the ignition, owing to the separate wire which is used from the battery. (4) I am expecting that high speed running will set the limit on the size of condenser, but it must be large enough to protect the points. R.{Sir Henry Royce} | ||