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 S.D. Heron of Ethyl Gasoline Corporation regarding exhaust valve temperature.
| Identifier | ExFiles\Box 174\2\ img302 | |
| Date | 19th December 1938 | |
| ETHYL GASOLINE CORPORATION RESEARCH LABORATORIES 723 EAST MILWAUKEE AVENUE DETROIT, MICHIGAN December 19, 1938. Reference Eml/R Mr. W.A. Robotham Rolls-Royce Ltd. Derby, England Dear Robotham: In reply to yours of December 2nd. I regret that I can answer practically none of your queries concerning exhaust valve temperature. The trouble with engines firing after cutting the switch has been experienced in this Country in all-head passenger car engines using aluminum heads. In one particular case this always occurred with aluminum but did not happen with the cast-iron head of the same shape and compression ratio. No work connecting this finding with valve temperature, however, carried out. In regard to reducing valve temperature by port design, etc., I regret that I have had practically no experience on this problem since about 1923 as my work has been almost entirely confined to aircraft engines and sodium-cooled valves. The last work I did with uncooled valves indicated that with a cast-iron head water-cooled cylinder it was possible to keep the valves black at 30 H.P. per cylinder and 1800 R.P.M. This work was described in an S.A.E. paper of mine entitled "Exhaust Valves and Guides" and published about 1924 (I cannot lay my hand on it at the moment). The measures taken in this work to ensure very rapid dissipation from the exhaust guide boss were rather extreme and probably cannot be applied in a passenger car engine. I shall be very interested to hear if you find any means other than sodium-cooling of sufficiently reducing valve temperature to cure after-firing. Yours sincerely, S.D. Heron SDH:REL | ||