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).
Investigation into the pros and cons of using Glycol or Pressure water cooling for car engines, based on experience from aero applications.
| Identifier | ExFiles\Box 131\5\ scan0115 | |
| Date | 5th December 1938 | |
| Rm{William Robotham - Chief Engineer}/Std.14/MH.{M. Huckerby}5.12.38. GLYCOL & PRESSURE WATER COOLING - CHASSIS. As requested by you, I have investigated the possibility of using Glycol or Pressure water cooling for chassis work and have been in touch with the Aero sections, both Engine and Installation, to obtain information re the pros and cons for car engines. The sources of information have been Lovesey on the Engine Side, Dr.Still (Chief Technical Officer, Hucknall) and Dorey on the Installation section, together with Greshan of the Laboratory. As regards general information about current aero practice, the following is a list of that obtained. (A) Ethylene Glycol. (1) Average operating temperature - 95°C. (2) Maximum operating temperature - 120°C, but tests have been run at 150°C. (3) Increase in metal temperature with Glycol as compared with water - approx. 40°C - this has severely increased the trouble of cylinder heads cracking between valves, experienced by the Aero people. (4) No doping of castings to remedy porosity is permissible with Glycol. (5) Glycol helps to prevent corrosion but attacks high temperature solder. (6) Pure Ethylene Glycol has a freezing point of -14°C = 25° of frost, which is not as low as the maximum frost protection we specify at present. (7) It is necessary to maintain coolant above a given % of Ethylene Glycol (for aero work minimum is 95% to cover operation at altitudes of 30,000 feet, while for car work minimum would probably be about 80%) and this necessitates sealing of cooling system since Ethylene Glycol is hygroscopic. In the event of overheating it becomes necessary to check % of Ethylene Glycol in coolant. | ||