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 specifications and suitability of a camshaft for a Bentley 111.
| Identifier | ExFiles\Box 98\5\ scan0012 | |
| Date | 2nd November 1937 | |
| c. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} BENTLEY 111 - CAMSHAFT. Please receive herewith E.CD.167 Inlet and Exhaust Cam Form - Bentley lll. This cam form gives the same valve lift curve as shown on LeC.5426 in accordance with the request in Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}4/AP.14.10.37., and is suitable for the altered rocker arm ratio instructed for Wraith lll. We have made the base circle diameter of cam 1.000" so as to keep the radius of the nose as large as possible. This has left us with an assembly clearance between cam nose and bore of bearing housings in crankcase of only .003" on the diameter. If the nose radius is still found to be too small it might be increased to say .062" without spoiling the cam, and very little lift would be lost. The valve lift obtained with this cam form is .407. Will you please detail and instruct the camshaft to this form experimentally for Bentley lll. All other particulars of camshaft are same as for Wraith lll. The distance of maximum scrub line from centre of tappet for this cam is only .032" greater than for the Wraith lll cam, and the Wraith lll tappets appear to be easily capable of dealing with this. DA.{Bernard Day - Chassis Design} | ||