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 camshaft design and timing for a Bentley engine to be used with silent tappets.
| Identifier | ExFiles\Box 85\3\ scan0036 | |
| Date | 4th December 1934 | |
| x 207 Hs{Lord Ernest Hives - Chair}/Smth.8/KW.4.12.34. Bentley - Camshaft for use with Silent Tappets. The slow running of the Bentley engine will be very bad if silent tappets are used in connection with the present camshaft. The overlap cannot be reduced with the present forms or the I.C. & E.O points will be too high. The inlet form developed for SpectreCodename for Phantom III to LeC.3855 has 5º less duration than the Bentley form, without sacrificing much valve lift. We therefore suggest that this form be adapted to Bentley, using the following timing - (Diagram shows valve timing) TDC Ex 230º In 230º 50º 50º Timing with .020 clearance 115º between the cams. Hs.{Lord Ernest Hives - Chair}1636 gives the cam form required. Hs{Lord Ernest Hives - Chair}/F.Ll.Smith. | ||