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 necessity of the LeC.4412 rocker control relief valve and results of a 10,000-mile test.
| Identifier | ExFiles\Box 10\3\ 03-page007 | |
| Date | 28th January 1937 | |
| -3- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}10/AP.28.1.37. We do not consider the rocker control relief valve LeC.4412 an absolute necessity, as by use of the increased capacity pump, oil is delivered to the timing gears and rockers at a lower speed than on the present standard 25/30. and Bentley which have the small pump. The inclusion of LeC.4412 is very debatable as with it, all the restriction can be taken out of the timing gear jet and if any foreign matter gets under the main relief valve then the rocker valve will prevent the main pressure from falling to zero. LeC.4692 or its equivalent in the form of Ph.III. filter combined with LeC.4412 relief valve ran throughout the 10,000 mile test on 6.B.IV. without trouble. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||