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).
Discussion with Solex Carburetter Co. about downdraught carburetters for the Spectre and Wraith models.
| Identifier | ExFiles\Box 121\2\ scan0166 | |
| Date | 1st November 1934 | |
| X3603 To E.{Mr Elliott - Chief Engineer} from E/Lid.{A. J. Lidsey} E/Lid.{A. J. Lidsey}2/HP.1.11.34. c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Mr H.C. Mills, of the Solex Carburetter Co. paid us a visit yesterday, at our request, to discuss downdraught dual carburetters for the SpectreCodename for Phantom III and Wraith. --------- SpectreCodename for Phantom III. This was discussed on the basis of applying one dual downdraught carburetter to the Bentley engine. Mr Mills told us that we could not expect quite such good slow running with dual downdraught carburetters as with our present horizontal type of carburetters. He raised the question of the type of balance used between the two halves of the induction system. We showed him what we used and he made the suggestion that we should probably get very much better results if we employed a balance pipe of quite large cross section area extending to the carburetter ports. This had been tried on rather similar systems and had been found very satisfactory. It might be worth while trying this on the existing SpectreCodename for Phantom III induction system. With regard to water heating, Mr Mills did not think that we should get away with water heating with the downdraught carburetter. Their experience was that a large amount of exhaust heat was necessary to obtain reasonably good slow running. It does not look, therefore, as if dual downdraught carburetters will help us appreciably on the SpectreCodename for Phantom III. We have arranged with Mr Mills that he will supply us with two dual downdraught Solex carburetters of 35 mm. throttle diameter, having the throttles arranged in the correct position to avoid throttle bias. These will be sent to us as soon as they can complete them. Mr Mills told us that they find it essential in all cases where downdraught carburetters are employed to provide a drain from the lowest point of the induction system. This consists of forming a small pocket in the induction pipe | ||