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).
The practical limitations of cam and valve design, prioritizing the 12-cylinder engine project over high-performance features.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan250 | |
| Date | 9th June 1931 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} ORIGINAL R1/M9.6.31. RECEIVED 10 JUN 1931 to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} CAMS AND VALVE AREAS. x5090. x7090. filed. We can only do that which is thoroughly practical, and we are giving you the best we can, P. 2. and J.{Mr Johnson W.M.} 1., which will be a good advance on P. 1., and 'China'. Then we must get the best out of these by the remaining features of carburetters, and compression ratios. If we attempt much greater rate of opening or height of lift we shall get noise and breakage failures; if we attempt larger valves we get no clearance around the heads of the valves and actually lose in volumetric efficiency. So we must not waste time trying for the impossible; to equal 4 valves per cyl., or supercharger, would probably be the next move. We must realise that high maximum speed is of very little importance in a luxury car, and we have other and more pressing work to do. We must get to our 12 cyl. job. R.{Sir Henry Royce} | ||