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).
Goshawk I engine battery ignition timing data at various speeds.
| Identifier | ExFiles\Box 37\1\ scan 229 | |
| Date | 28th April 1921 | |
| Contd. (2)" Hs{Lord Ernest Hives - Chair}9/LG28.4.21. Goshawk I Battery Ignition. Positions on flywheel B.T.D.C. at which horse power drops by retard or advance at various speeds. (Columns added by EFC) Revs. Retard. Advance. R.{Sir Henry Royce} A.{Mr Adams} Av. 500 10° 40° 0 0 0 1000 12° 43° 2° 3° 2½° 1500 19° 50° 9° 10° 9½° 2000 26° 52° 16° 12° 14° 2500 28° 60° 18° 20° 19° 3000 30° 61° 20° 21° 20½° The above figures were taken when firring with the battery ignition. The previous figures were when using the magneto. Hs.{Lord Ernest Hives - Chair} | ||