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).
Thermostatic air temperature control and its effect on carburettor engine performance.
| Identifier | ExFiles\Box 123\1\ scan0099 | |
| Date | 26th August 1936 guessed | |
| REPORT ON THERMOSTATIC AIR TEMPERATURE CONTROL Description of Tests Experiments were made in order to determine the effect of various temperatures of the intake air to a carburetter on engine performance. The engine chosen for the experiments was a 1,200 C.C. overhead inlet and side valve exhaust made by the Coventry-Climax Co., of Coventry and supplied in bulk to the Triumph and Crossley Company. The carburetter fitted was an S.U. down draught. The reason for the use of this engine was the fact that it could be used without a hot-spot on the induction system, thereby cutting out one variable. The air temperature control instrument supplied was of the air cleaner type fitted with a sleeve actuated by means of a Thermostat to control the admission of cold or hot air at predetermined temperatures. The necessary heat was supplied by exhaust gases circulating through heater coils. Before carrying out any serious test bench work the writer thought that it was best to find out what the actual air temperatures were that were under the bonnets of motor cars under road conditions and a test course was used which included a climb of Box Hill. Road Tests Several cars were tested such as a 1927 Morris, a Talbot 95 and Mr. Grose's 12 h.p. Standard, and were driven at normal speeds including observing the 30 m.p.h. limits. The under bonnet temperatures in every case varied between 98°F.{Mr Friese} and 108°F.{Mr Friese} After climbing Box Hill each car varied between 116°F.{Mr Friese} and 120°F.{Mr Friese} The actual day temperature in every case was 70°-72°F.{Mr Friese} Two ascents were then made of Box Hill on the Morris car, one with the bonnet closed and the other with the bonnet open in order to lower the temperature. The temperature at the top of the hill was 120°F.{Mr Friese} for the closed bonnet test and 105°F.{Mr Friese} for the open. The performance was a trifle better with the bonnet open which is confirmed by test bench results. CONTINUATION NO. S. SMITH & SONS (Motor Accessories) LTD. CRICKLEWOOD WORKS, LONDON, N.W.2. R.P.81 | ||