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).
Technical memo on valve spring improvements for 20 HP and Aero engines, highlighting the advantages of taper springs.
| Identifier | ExFiles\Box 56\2\ Scan073 | |
| Date | 18th March 1929 | |
| x290 R3/M18.3.29. RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} Hs.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} c. to SG.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} VALVE SPRINGS - SS.{S. Smith} 20 HP. X.290 & AERO F.{Mr Friese} H.{Arthur M. Hanbury - Head Complaints} & R.{Sir Henry Royce} X.2993 Between us we have produced valve springs which promise to be better than any of our earlier springs - (though some of the features are of Silver Ghost springs.) I am very anxious that we take full advantage of this knowledge in all our engines, including 20 HP. and the aeros F.{Mr Friese} H.{Arthur M. Hanbury - Head Complaints} and R.{Sir Henry Royce} (1) Apparently there is a decided advantage in a taper spring as well as very practical. (2) A spring of very high natural frequency, - probably (1) helps this because in a taper spring each convolution has a different frequency. (3) Figure of Merit can be improved by the coarse wire, and a spring of low max. and high stress range, which gives (2). LeC.2681 is to be tested when convenient, as an improvement on standardised SS.{S. Smith} E.78071. This with long cams to recent form should save us from jumping valves and their destructive effects. R.{Sir Henry Royce} | ||