'Brightray' coated exhaust valves and the material specifications for 'Silcrome' seat inserts.
| Identifier | ExFiles\Box 174\2\ img234 | |
| Date | 21th January 1938 | |
| COPY To Rm. {William Robotham - Chief Engineer} LP {Mr Lappin} /GOS.2/RS. {Sir Henry Royce's Secretary} 21.1.38 EXHAUST VALVE AND SEAT MATERIAL. Our experience is that 'Brightray' coated exhaust valves are the most suitable for aero engines. Completely 'Brightray' coated valves, i.e. with Brightray covering the seating portion of the valve as well as the top of the head, are now a standard fitting in Merlin(Aero Engine) engines. The seat inserts are of S/SLV material which is almost identical with the "Silcrome" mentioned by Mr. Young, the specification limits being:- Carbon .......... 0.4 to 0.5% Silicon .......... 3.25 to 3.75% Chromium ........ 7.5 to 8.5% LP {Mr Lappin} /GOS. | ||
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).