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 carbonisation, aluminium pistons, and conventional water cooling systems.
| Identifier | ExFiles\Box 178\1\ img025 | |
| Date | 15th February 1926 guessed | |
| - 9 - (g) Carbonisation. A dirty engine will not cause a car to over-heat unless it promotes detonation which is only likely to occur where a fairly high compression is used. (h) Aluminium pistons. Aluminium pistons from the tests which we have conducted, have no appreciable effect on heat transmitted to the cooling water. (3) CONVENTIONAL WATER COOLING SYSTEMS. (a) Methods of water circulation. In order to get the best out of, any conventional water cooled system it is necessary to have a certain minimum water circulation. There are two main reasons for this:- (1) A rapid flow of water round the cylinder head assists the latter to get rid of heat and prevents the formation of local hot spots with consequent possibility of detonation. The increase of the conductance of the water film in contact with the cylinder walls with increasing flow is not yet fully established. Quoting some American examples on the subject, however, we have the temperature on the combustion side of the cylinder walls for a water temperature of 200°F is 253° for a good pump circulation system, but 536° for a thermosyphon system in which the temp. of the water is also 200°F.{Mr Friese} As no figures for the circulation of the two systems are given they are not of much value. We have made no experiment on these particular lines as yet. contd. | ||