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).
Specification sheet listing the standard quantities for the Goshawk Ignition system.
| Identifier | ExFiles\Box 54\5\ Scan198 | |
| Date | 21th August 1922 guessed | |
| X. 3485 X. 3485 - GOSHAWK IGNITION. Standard quantities :- Coil resistance .5 w " inductance .011 henry Circuit resistance 2.05 w Ballast resistance 1.55 w at normal working current of average value 1.1 ampere or R.M.S. value 1.67 ampere (these being for 8 volt supply) 2.59 volts Normal distributor speed = 500 R.P.M. Make ratio - .5 Ballast volts (R.M.S) = 2.6 | ||