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).
Testing new Bentley valve springs on the Wraith III engine.
| Identifier | ExFiles\Box 10\3\ 03-page011 | |
| Date | 1st March 1937 | |
| SECRET. To Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} Copy to Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} 654. E/FSN.1/MN.1.3.37. Wraith III Valve Gear. We are hoping to use the new Bentley valve springs to Lec.5417 on the Wraith III engine, and since these springs give greater excess loads than the standard springs we think it may be possible to eliminate the tappet springs on the latter engine, which will be desirable from the point of view of cost. In order to give us a lead as to the effect of the omission of the tappet springs in reducing the bouncing speed, we should be pleased if you would run a Bentley engine with the tappet springs removed, as discussed with Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} this morning, and determine the bouncing speed of the valve gear. E/FSN. | ||