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).
Carburettor and engine component redesigns and performance summaries.
| Identifier | ExFiles\Box 179b\2\ img073 | |
| Date | 9th November 1932 | |
| -3- Hs.{Lord Ernest Hives - Chair}/Cav.1/MJ.9.11.32. Cont'd.{John DeLooze - Company Secretary} pipe from the accelerating pump should be taken close to the throttle edge and below that half of the butterfly that opens upwards so that the priming squirt of petrol misses the throttle and is projected without obstruction into the carburetter bore. With this pipe in its original position a larger priming - or accelerating - supply is necessary as a certain amount is wasted by striking the throttle and falls back into the intake when accelerations up to only relatively small throttle openings are made. This point should be noted in the re-design of the carburetter. The single slow running jet and discharge orifice have proved adequate and excellent slow running and metering have been obtained. The means of locking the mixture adjusting screw at the top of the slow running unit by means of the loose brass piece should be modified in the redesign. At present it is too difficult and would be impossible when installed in some machines. The "economiser" valve at present arranged to give a slight richening up at full throttle which would be an advantage if the engines are run full throttle at ground level - such as for the special High Speed "Furies". If used in conjunction with a boost control this could be made to give extra richening for the take off condition. For Aerobatic work the float chamber needs redesigning to reduce the air capacity above the fuel level in order to prevent the fuel spilling away from the jet passages during various manoeuvres. This job is now in hand. SUMMARY. (1) The Goshawk 1 blower on a Std. Kestrel engine has shown a considerable reduction in the detonation tendency of the engine enabling advantage to be taken of higher boost pressures. (2) Distribution is good - and from test bed experience appears superior to the Kestrel S. engine. (3) The new form of carburetter appears very satisfactory and the accelerating pump allows much more vigorous "snap opening" of the throttle than the present standard engine. (4) It would appear that thermostatic control of the water heating of the carburetter could be applied with advantage. A rapid circulation of water is needed for quick warming up which could be cut down to normal when the operating temperature is reached. It should not be difficult to apply a small thermostat in the water outlet at the base of the carburetter. | ||