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 from the Royal Flying Corps regarding carburettor adjustments and throttle control issues on an experimental Eagle engine.
| Identifier | ExFiles\Box 37\2\ scan 200 | |
| Date | 17th September 1917 | |
| Testing Squadron, Royal Flying Corps, Martlesham Heath, Nr. Woodbridge. Messrs. Rolls-Royce Limited, Nightingale Road, DERBY. In reply to your letter dated 17th September No. EH1/LG17.9.17 No A/7446 with your experimental Eagle engine has just left us. We found as you say that when the machine was first sent to Martlesham heath the carburetters were adjusted to be too weak at 1/4 throttle. We had this readjusted and we found that even when readjusted there was sufficient altitude control up to 20,000 ft. I think the real difficulty at present about the carburetters fitted to this engine is that the mixture when throttled down to cruising speeds is much weaker than the mixture when full out, so that if the carburetters are readjusted to give correct results full out, the engine runs very roughly at cruising speeds. In order to get good throttle control it is therefore necessary to run the engine on the rich side at full throttle. I am shortly sending in a full official report about the petrol consumption tests we carried out. On the whole the needle type of fine adjustment seems to be very satisfactory. I should imagine, however, that it would be very difficult to manufacture the needles so that you get exactly the same effect on different carburetters If you have time I should be glad to hear whether you think this manufacturing trouble can be got over satisfactorily as (CONTD) | ||