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).
New Spectre camshaft design with negative overlap and specific timing.
| Identifier | ExFiles\Box 93\5\ scan0009 | |
| Date | 1st October 1934 | |
| 7469T 307 RHC.{R. H. Coverley - Production Engineer} From Hs{Lord Ernest Hives - Chair}/Smth. Hs{Lord Ernest Hives - Chair}/Smth.4/MA.1.10.34. SPECTRECodename for Phantom III CAMSHAFT. We are not satisfied with the slow running of SpectreCodename for Phantom III and wish to try a camshaft with a negative overlap. Will you therefore make a camshaft in which all the cams are to the Inlet form E.85234 and with an angle of 117° between the cams. We will call this Hs.{Lord Ernest Hives - Chair}1536 and the timing with .020 clearance will be as under. [Diagram showing cam timing with labels: Ex 230°, IN 230°, 2°, 2°, 52°, 52°] This shaft is similar to Ex.15042 but with a wider angle between the cams. Hs{Lord Ernest Hives - Chair}/Smth. | ||