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).
Carburetion experiments, comparing single versus dual carburetter setups and engine layouts.
Identifier | ExFiles\Box 21\6\ Scan141 | |
Date | 10th March 1934 | |
X4217 To Sgr from E.{Mr Elliott - Chief Engineer} c. WOP. Hs.{Lord Ernest Hives - Chair} By re Carburation Experiments. Replying to your memo Sg.{Arthur F. Sidgreaves - MD}6/E.9.3.34, we are of the opinion that we could only get good distribution from a single carburetter if we have the exhaust cooking pot on the induction system as is used on the Terraplane. Further we can only have this if we accept the exhaust and induction manifolds from the same side of the engine. It follows we can only have this either by having a side valve engine or by keeping our overhead valves all in one line as on our present 20/25. If we do this we shall strictly limit the power output, and we shall be unable to offer the public any more power than the Terraplane gives which definitely clips our wings. We think we have got to keep our valves transverse to the crankshaft which means that we have got to find a solution of the distribution problem. We believe under these circumstances we can get good distribution by means of two carburetters. One scheme we have is as you mention, a new firing order using an induction system similar to the Bentley. We are also arranging to keep a more normal firing order and use what we call a 2/4/2 induction system with some form of double carburetter. This we know is a very successful scheme and is employed on some of the American Eights. Mr Pomeroy told me yesterday that he is getting excellent results from it on the Daimler Straight 8. We are, therefore, not leaving too much to chance but we do feel we have got to arrange our schemes so that they will not have the same limitations in output that the Terraplane possesses. The Terraplane performs so well up to the limitations set by its price that the only way we can beat it as a power unit is to remove some of those limitations and give an extended performance. Le 7416 E.{Mr Elliott - Chief Engineer} | ||