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).
Experimental modification to the Wraith III valve rockers to reduce valve lift.
| Identifier | ExFiles\Box 10\3\ 03-page053 | |
| Date | 19th August 1937 | |
| E.{Mr Elliott - Chief Engineer} Dept. c. to Rm.{William Robotham - Chief Engineer} c. to Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} 654 DA.{Bernard Day - Chassis Design}1/G.19.8.37. WRAITH III - MODIFIED VALVE ROCKERS TO GIVE .350" VALVE LIFT. As requested in Rm{William Robotham - Chief Engineer}/8/R.9.8.37. we send herewith E-CD.9 showing an experimental modification to valve rocker gear to reduce the valve lift from .400" to .350", and also altering the rocker oiling system to that used on the latest Phantom III rockers without hydraulic adjustment. This has been designed for use on an existing cylinder head, and is not suitable for a permanent scheme, owing to the weakness of the rocker shaft where the bracket stud passes through it .075 offset. Will you please detail and instruct the necessary parts for the experiment. DA.{Bernard Day - Chassis Design} | ||