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).
Crankshaft stiffness, bearing materials, and valve springs for a V8 engine.
| Identifier | ExFiles\Box 126\3\ scan0079 | |
| Date | 2nd April 1937 guessed | |
| - 3 - They stressed the point of crankshaft stiffness and though their V8 is a much shorter shaft than the Bentley and 25/30 the journal diameter is 2.400 against our 2.250, the crankpins being identical and 2.000 dia. It was stated that stiffening of the shaft does appreciably improve the bearing life. The big end bearings are in NS{Norman Scott}5 (cadmium nickel) and the main bearings in a normal Whitemetal Babbit. Asked why they did not use NS{Norman Scott}5 material for the main bearings it was said that W/M was quite satisfactory but if necessity demanded a main bearing with a better life, then the first thing they would try would be NS{Norman Scott}5. At present a set of shells are being metalled for us with this NS{Norman Scott}5 by the National Smelting Co. for trial as main bearings in a Bentley unit so that we shall soon have evidence of their merit in comparison with W/M.{Mr Moon / Mr Moore} Valve Springs. Valve springs are received completely finished from the Lion Spring Co. and are made from "Swedish Wire" similar to the material which we have found very satisfactory in springs made for us by the "Tempered Spring Co" The production springs are dipped in a bath of lacquered varnish to prevent rust forming through condensation, this having overcome quite a lot of failure in service. Service springs which are kept in stock or sent to agents are enamelled for protection. They are of the opinion that the "Swedish" wire is the most suitable of all as valve springs. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||