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).
Engine temperature tests comparing evaporatively cooled and water-cooled conditions, detailing component failures like water leaks and cracks.
| Identifier | ExFiles\Box 179\3\ img055 | |
| Date | 1st March 1932 guessed | |
| -2- H8/Lev.1/AMB.Z.32 contd. Running evaporatively cooled the temperature increased until after a period of five minutes a temperature of 275°C. was recorded on all three thermo couples. The inlet couple of No.3 cylinder rose steadily but the exhaust of No.3 was at first less rapid in its rise but after three minutes quickly reached the same temperature. We next changed the sparking plugs from Lodge A.2's to Lodge X.170's and the maximum temperature reached now was reduced to 210°C. (See diagram 2.). Two full throttle power curves were now taken on TEL., the one under evaporative cooled and the other under water cooled conditions. Evaporatively cooled, the inlet couple of No.3 cylinder was again the hottest and reached a temperature of 240°C. at 795 B.H.P. and 2700 R.P.M. The other couples reached only about 130°C. Water cooled, the highest temperature recorded was only 117°C. (Curve No.2). The particular engine used for these tests was built up with one standard block to which the thermo couples were attached, and the other block was the detachable head type. During the test both cylinders developed internal water leaks and upon examination after stripping it was found that the joint rings of the standard block showed marked evidence of blowing past. As stated at the beginning of this report, leaks usually occurred adjacent to the exhaust plug and gas starter boss but in this particular case all the leaks had occurred between adjacent cylinders or at right angles to the plug bosses. Four cylinders of the detachable head block had developed cracks between the valve seats. The total running time on these tests did not exceed 24 hours. Summary. We regard these tests as only a preliminary investigation on the temperature effect in connection with the cylinder problem. These results, however, show the high cylinder temperatures that can be reached under evaporatively cooled conditions when the boost is increased and when detonation is present as for example under the "take off" condition. | ||