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).
The Spectre Camshaft and Valve Springs, detailing changes to the tappet radius and valve lift curves.
| Identifier | ExFiles\Box 93\5\ scan0001 | |
| Date | 29th March 1934 | |
| X47 307 To Mr. [redacted] from E/PSN. E/PSN.2/HP.29.3.34. c. Mr. Ws. Hs.{Lord Ernest Hives - Chair} SpectreCodename for Phantom III Camshaft and Valve Springs. We send you herewith LeC's 3855 and 3856 of the SpectreCodename for Phantom III Inlet and Exhaust Valve Lift Curves, and LeC.3849 of the valve and tappet springs. It should be noted that the radius on the end of the tappet has been increased to 1 1/4" which gives a cam with concave flanks of very large radius which permit grinding wheels of the largest diameter to be used. It should also be noted that the lifts during the period of positive acceleration have been given for every degree of camshaft angle which should enable a more accurate master cam to be generated. E/PSN. | ||