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).
Pre-ignition problems caused by mutual induction effects from using double ignition systems.
| Identifier | ExFiles\Box 37\1\ scan 103 | |
| Date | 14th April 1921 | |
| X 3199 R.R. 235a (100 T) S.H. 89. 22-7-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2769 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to E.{Mr Elliott - Chief Engineer} Hs{Lord Ernest Hives - Chair}10/LG14.4.21. X.3199 X.3129. RE BATTERY IGNITION. It is a fact that the pre-ignitions we have had on our cars due to mutual induction effects, have shown up more because of our using double ignition. One of our tests for mutual induction is to run on both ignitions with the ignition lever retarded which means that under that condition the magneto is firing considerably earlier than the battery. This will, in all cases, show up the trouble if it exists. Hs.{Lord Ernest Hives - Chair} | ||