Data table for the Goshawk I engine, detailing battery ignition timing settings (retard/advance) against various RPMs.
| Identifier | ExFiles\Box 54\5\ Scan148 | |
| Date | 28th April 1921 | |
| Contd. -2- Hs {Lord Ernest Hives - Chair} 9/LG28.4.21. ---------- Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) 1 Battery Ignition. Position on flywheel B.T.D.C. at which horse power drops by retard or advance at various speeds. | Revs. | Retard. | Advance, | |---|---|---| | 500 | 10º | 40º | | 1000 | 12º | 43º | | 1500 | 19º | 50º | | 2000 | 26º | 52º | | 2500 | 28º | 60º | | 3000 | 30º | 61º | The above figures were taken when firing with the battery ignition. The previous figures were when using the Magneto. Hs. {Lord Ernest Hives - Chair} M.M. 50M (59.1)2 H SET 12-3-21 C 2013 | ||
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).