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).
The performance of a water-cooled unit, detailing issues and comparing temperatures to an air-cooled version.
| Identifier | ExFiles\Box 133\1\ scan0116 | |
| Date | 17th September 1936 | |
| -12- Hs{Lord Ernest Hives - Chair}/Ed.{J. L. Edwards}1/KW.17.9.36. Water Cooled Unit. Not much work was done on this unit due to difficulties in obtaining a satisfactory water circulation, and the fact that no oil cooler was incorporated, which led to overheating of the oil, with subsequent mechanical failures. However, a little work was done, and it would appear that the water cooled unit gives about 8% more power and 20% better detonation than the air cooled job. This power, increase, it ought to be remarked, is only for the boosted conditions. Messrs. Rudge-Whitworth Ltd. tried air and liquid cooled jobs naturally aspirated, and they state that there was nothing to choose between them. It would appear therefore that water cooling the unit cools off the inlet port sufficiently to enable a higher volumetric efficiency to be obtained, with consequent power increase. This would seem to be borne out by the results in Fig.XXVII, which shows a temperature of about 165°C., as against the air cooled 245°C. for a consumption loop under the same conditions. Temperatures on the water cooled unit are considerably different to those of the air cooled job, and a brief commentary is as under :- Cylinder. (1) The water jacket only extends to about half-way between planes A & B in Fig.IX, and it will be seen that the temperatures on this uncooled part at the base of the cylinder are higher than any of the others, being about 180°C. (2) The temperature of the block is otherwise very uniform; indeed only the two side couples 10 and 12 rise much above the average level of 125°C. going up to 141°C. and 152°C. respectively. It is rather difficult to explain this, but it is thought that possibly the blame may be put down to the thermo-couples having been inserted just too far, and being nearer the cylinder wall in consequence. | ||