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 discussing the pros and cons of using Ethylene Glycol as an engine coolant.
| Identifier | ExFiles\Box 151\3\ scan0133 | |
| Date | 18th January 1930 | |
| HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}2/WJ. P. Gaye, Esq., c/o.{Mr Oldham} H.M.A. R.100., Cardington, BEDFORD. Jan. 18th. 1930. Dear Gaye, Referring to your enquiry about Ethylene Glycol. We had some experience of this stuff on the Schneider Cup engines. When it is used by itself as a circulating medium in the cooling system it has a number of disadvantages. To mention only a few (1) the cylinder temperatures rise as the temperature of the cooling medium rises and so detonation is liable to ensue under sustained full throttle work such as might conceivably be necessary on an airship engine. (2) Unless the liquid is obtained entirely free from water from which it has a decided affinity, local explosions take place when the Ethylene Glycol reaches 100°C. due to the water turning to steam, and this is likely to cause damage to the radiators etc. With perseverance, this substance could probably be made to work but we prefer to go for steam cooling which gives an absolutely constant operating temperature very little higher than at present with the added advantage that there need be absolutely no parasitic drag as spar and wing radiators can be used. To get over your freezing difficulties, we do not think there is any objection at all to using Ethylene Glycol in a portion of about 30% which should give you immunity from freezing down to well below zero. Ethylene Glycol can be obtained in the form of prestone from Messrs. Chalas and Sons Ltd., Finsbury Pavement House, Moorgate, E.C.2. or Imperial Chemical Industries Ltd., Leicester., and it is 10/- per gallon. It is equally good from either place. | ||