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 icing issues, design choices, and testing by various engine manufacturers.
| Identifier | ExFiles\Box 27\3\ Scan230 | |
| Date | 15th May 1939 guessed | |
| 24 Both companies made an invariable practice of checking the mixture temperature after the carburettor, and Wrights give a curve in their latest installation Folders - showing the temperature required to be maintained after the carburettor for given outside air temperature. This curve is as shown on the accompanying sheet. Both engine firms had felt so strongly about the icing danger that they gave it as the main reason for adopting the Chandler Groves and Bendix Stromberg carburettors. These carburettors are both supposed to be non-icing, but some trouble has been experienced through ice collecting in the Chandler Groves carburettor, and in consequence some heat is usually supplied. Little trouble appears to have been experienced with the Bendix-Stromberg carburettors and Pratt & Whitney are now fitting this type of carburettor with an air intake which merely takes air either from outside of from inside the cowl. Carburation Wrights use the Chandler Groves carburettor, and Pratt & Whitney are now in production with the Bendix-Stromberg type. The impression was gained at Wrights that they were having difficulty with the carburettor, and this was confirmed by outside sources. The trouble appears to lie in the metering needle, which gives variable results, so that every carburettor has to be individually tuned. Wrights are putting down an ambitious carburettor blowing test plant. This was in course of construction, and will comprise five blown chambers, and Wrights hope to be able to make all settings on the rig. The Chandler Groves carburettor is said to be useless for anything but a narrow range with fixed pitch airscrew. | ||