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).
Departing from the common S.U. pattern carburetter towards a new single semi-expanding design.
| Identifier | ExFiles\Box 179\1\ img078 | |
| Date | 9th November 1931 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} EX. CARBURETTERS. We want to depart from the very common S.U. pattern for various reasons. Amongst others the reputation of this pattern is not very good owing principally to the wear of the needles. We think our most important development must be confined to a single carburetter because this has the advantage of silence and simplicity. We must be very careful in making any alteration to RR. engines not to depart from the restful character that we obtained in the early days. Naturally we wish to continually progress in performance and HP. available, and expect to do so, as was shewn several years ago, but we must confine ourselves to schemes which do not depart, but rather increase, the restful silence and smoothness for which we have such a valuable reputation. Naturally the increase in the RPM. that the engine must of necessity run to obtain the increased performance brings all sorts of trouble, such as vibrations, etc, that makes our objective most difficult to obtain, and it suggests that as soon as we have come across something which is fundamentally against silence and smoothness we must drop the idea of making it our standard. This seems to be the case with certain types of carburetter including all the twin ones, and also certain valve timing, including all those where the inlet opens too early. The most promising schemes known to us all appears to be the single carburetter of the semi-expanding type, because we do not seem to be able to get our ideals from either the completely expanding carburetter of the S.U. type, or any of the completely fixed ones, such as Claudel, Solex, Zenith, and Stromberg. We are expecting to complete the design of the vertical (uptake) single semi-expanding carburetter this week. We have given it great care so that it shall perform well with the maximum of simplicity of construction, and great and lasting reliability. R.{Sir Henry Royce} | ||