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).
Letter to The S.U. Company Ltd. regarding the performance of their carburetter on a Kestrel engine.
| Identifier | ExFiles\Box 31\5\ Scan264 | |
| Date | 7th December 1934 | |
| 81487. Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Lov.{Mr Lovesey}19/KW. 7th December, 1934. The S.U. Company Ltd., East Works, Bordesley Green Road, Adderley Park, Birmingham. For the attention of Mr. Davey. Dear Sirs, Re S.U. Carburetters for Kestrel Engine. We have carried out a considerable amount of work on the S.U. Carburetter on Kestrel engine, and from the results we have noted several points which we would like to discuss with you. Would it be convenient for you to pay us a visit next Tuesday, the 11th inst., when we could discuss the various points. Regarding the automatic correction of the carburetter on a constant power climb, this is no longer a mystery but is due to the slope of the throttle curve. We have enclosed two curves for your perusal comparing the S.U. with the Kestrel carburetter, and it will be observed that the S.U. has a considerable richening effect when throttled from a full throttle setting, and conversely when set correctly at part throttle the mixture weakens off considerably as the throttle opening is increased. This is precisely what happens when we carry out a constant output curve from ground level up to full throttle height. As the throttle opening is increased to maintain the power output at altitude, the weakening characteristic of the throttle curve balances out the richening effect of the reduced density equivalent to the altitude, with the result a constant full flow is | ||