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 British Thermostat Co. Ltd. regarding the design and testing of a bonnet louvre thermostat.
| Identifier | ExFiles\Box 156\1\ scan0150 | |
| Date | 7th January 1936 | |
| X1326 Exptl. Dept. Hs {Lord Ernest Hives - Chair} /Std.S/KW. 7th January, 1936. The British Thermostat Co.Ltd., Windmill Road, Sunbury, Middlesex. For the attention of Mr. Martin-Hurst. Dear Sirs, Replying to your letters of December 5th, 1935 and Dec. 16th, 1935, for which we thank you; we will deal with the former first. We thank you for the calculations shown in this letter and your offer to prepare a design of thermostat. As a matter of interest we tested the shutters and found that a load of only 1 1/2 lbs. was needed to operate them, instead of 7 lbs. On this basis we calculated that we could use a reasonable size of thermostat by spring loading it and using Isopentane for a filling, operating above the boiling point at normal temperatures. We regret, however, that at present at any rate we shall not be able to take any further interest in a bonnet louvre thermostat. As a result of tests which we have carried out, both on our own cars and on the Lincoln car which is fitted with thermostatically controlled louvres, we do not derive any advantage from such louvres when the water temperature is shutter-controlled, the net result being that the louvres remain open under all running conditions and exercise no control over the under-bonnet temperature. | ||