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).
Specifications for the Spectre Camshaft, detailing cam forms, angle, and timing.
| Identifier | ExFiles\Box 93\5\ scan0016 | |
| Date | 11th March 1935 guessed | |
| Hs.{Lord Ernest Hives - Chair}1832. SpectreCodename for Phantom III Camshaft. Cam forms, inlet and exhaust Hs.{Lord Ernest Hives - Chair}1838. Angle between the cams - 116º. Timing with .020 clearance :- I.O. 4º ATDC. E.O. 48º BBDC. I.C. 44º ABDC. E.C. 8º BTDC. Other details to E.86371. | ||