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).
Tempering valve springs in an oil bath and the effects on engine performance.
| Identifier | ExFiles\Box 4\7\ 07-page32 | |
| Date | 6th August 1913 | |
| COPY. X683. HB{C. E. Harcombe}/P6813. August 6th. 1913. E.{Mr Elliott - Chief Engineer} J.{Mr Johnson W.M.} Ma. Pd. Wor.{Arthur Wormald - General Works Manager} Re Valve Springs tempered in oil bath at Derby. X.472 I understand from this that we can temper valve springs quite low enough (i.e. until they would take a permanent set before breaking in the oil bath). With such perfectly tempered springs they fail to run on engines the valves of which are not following the cams. There are newly proportioned springs requisitioned in which the stresses are lower, these can be arranged to give greater set, so that the engines will run faster without leaving the seats. The cams can be altered somewhat for a still higher speed but it will slightly lessen the output of the engine. The springs in the tappets might with advantage be arranged to give a little more pressure if the metal in these springs is not highly stressed or more metal can be got in these or the ones on the Northcliffe engine. The oil bath was purchased especially for such tempering. It should be filled with oil of the highest flash point that it is possible to obtain. One thinks of the oil supplied for air cooled engines as probably being the best. [Handwritten note in left margin] I suggest that we try to make the springs cams etc. correct for 2500 revs. but no faster as I consider that this is about as fast as our engine should run. Will Exp.Dp. find out how fast Lanchester engine goes before the valves leave the cams. COPY. | ||