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).
Outlining a series of tests to compare different materials and designs for exhaust valves.
| Identifier | ExFiles\Box 96\2\ scan0096 | |
| Date | 16th January 1936 | |
| To RHC.{R. H. Coverley - Production Engineer} Hs{Lord Ernest Hives - Chair}/Swdl.{Len H. Swindell}6/KW.16.1.36. Exhaust Valves. We are about to start a series of tests in order to find out if it is possible to substitute KE-965 steel by a less expansive steel. In conjunction with the above, we are going to try out sodium filled valves and its effect upon expansion of the valves. If the expansion can be substantially reduced and at the same time have valves which will stand up to the job, the following advantages will be gained. (1) Reduced valve guide clearance and consequently quieter valve seating, together with increased heat conductivity to the valve guides. (2) Smaller tappet clearances, resulting in quieter valve operation and ensuring that the valves are not off the seats when prolonged high speed running is carried out. The materials proposed for comparison are - (1) KE-965 Stellited and non-stellited, also sodium filled. (2) Standard S/SLU. Stellited. Chrome plated stems with reduced clearance in the valve guides, also sodium filled valves. (3) Silchrome X. Stellited. Chrome plated stems with reduced clearance. Also sodium filled. American Material. 20% C.R. 2 1/2% Ni. 7% C. 2% Si. 6% Mn. (4) We have been recommended to try a Brown-Bailey steel, Q.S.S., which is supposed to have a much higher hot strength than standard silchrome; other than this we know very little about it; i.e., whether it will stellite or take chrome plating we cannot say. All the valves on which these comparisons are made should incorporate the modified tulip to LeC. 4915. | ||