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).
Cylinder head temperature testing on a Kestrel engine under various cooling conditions.
| Identifier | ExFiles\Box 179\3\ img054 | |
| Date | 1st March 1932 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Lov.{Mr Lovesey} c. S.G. c. sor. Rg.{Mr Rowledge} c. L. BY.{R.W. Bailey - Chief Engineer} ORIGINAL Hs{Lord Ernest Hives - Chair}/Lov.{Mr Lovesey}1/ADS.3.32. X38106 x965 CYLINDER HEAD TEMPERATURES ON KESTREL. When water leaks occur at the top joint ring it is usually found that this takes place at that part of the ring next the bosses carrying the inlet and exhaust sparking plugs and more frequently the latter place only. It would appear that this could be associated with a temperature effect. In order to determine the temperature at these places and see how this increased with evaporative cooling, a Kestrel was built up with thermo couples at these points inside the water jacket as shown in the sketches at the top of curve No.1. Iron Eureka thermo couples were used previously calibrated against a high reading thermometer. The wires were fixed to 1/8" dia. brass plugs and driven into 1/8" holes drilled in the bosses. The wires were led through glands in the core plugs. For the first test the engine - full supercharger - was run at its rated boost pressure of -1/4 lb/sq.in. and a comparison made of the temperatures under evaporative and water cooled conditions. The results are shown on curve No.4. Unfortunately, one couple on the exhaust side of No.4 cylinder broke during the test. We were particularly keen to get the temperature at this spot because this cylinder only had a water hole drilled between the sparking plug and gas starter inserts. During nearly all the tests the inlet couple of No.3 cylinder showed higher temperatures than at the other two positions. Referring to the curves taken at the rated boost and running evaporatively cooled, we see that the temperature of the hottest spot was on an average only 20°C. higher than the steam and water outlet. Also when running water cooled the temperature was only 20°C. higher than the water outlet. The next test was taken under the "take off" conditions i.e. 1850 R.P.M. and + 1.8 lbs/sq.in. boost (see curve No.3). Running water cooled, in which case the audible detonation was approx. Y10°, the maximum temperature was only 28°C. above that of the water outlet (diagram 1.). | ||