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).
Valve material performance, detailing failures and comparing old designs with the current standard.
| Identifier | ExFiles\Box 54\3\ Scan216 | |
| Date | 11th May 1928 | |
| R.{Sir Henry Royce} WOP. Hs.{Lord Ernest Hives - Chair} Rg.{Mr Rowledge} Bj. Hl. EP.{G. Eric Platford - Chief Quality Engineer} Hm.{Capt. W. Hallam - Head Repairs} XU634 BY4/G.11.5.28. VALVE MATERIAL. Referring to R5/M7.5.28. I am inclined to think that the correspondence which has been going on in connection with the above subject has introduced a wrong atmosphere. In the first place we have not had a single complaint from the Repair Department inconnection with the present standard material since it was introduced, neither from the point of view of a valve breaking or from the seating on the valve warping. Prior to the introduction of the present material, warping of the seat of the valve was a regular trouble. In connection with aero engines we have had two failures on the type test engine. In each case the valves were American made, and Laboratory examination showed as reported by Hl. that the trouble was due to excessive slag in the material. In addition to these I know of three other failures outside, two of these were undoubtedly due to valve spring failure in the first place, and to fully appreciate just what a valve has to stand when the spring breaks one should actually see it, as the punishment is terrific. The third valve which failed was one of the first valves produced in the new material for Imperial Airways, in that case it broke at the tappet end. The valve was produced rather hastily and was not our present design. In putting the facts as above I have fully discussed the matter with the Repair Department and EP.{G. Eric Platford - Chief Quality Engineer}, and my report is based upon the facts as understood by these two Departments. No turbulent head will be turned out with the old section of the tulip on the exhaust valve. All valves made to the original design are being used on the inlet side. | ||