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).
Technical comparison of various thermostat and radiator shutter systems for engine temperature regulation.
| Identifier | ExFiles\Box 39\4\ Scan042 | |
| Date | 3rd March 1921 | |
| contd. -2- OY4/G3.3.21. on Rolls-Royce and other cars in this country. About thirty Rolls-Royce cars have now been fitted with this device, apparent-ly with complete success. A sample Galli-ator outfit was taken to England by me last Winter, with attachments for operating either by oil or vacuum. The Winterfront theromostat is heated by air currents and conduction from the radiator, the thermostat being enclosed in the sheet metal frame of the device in front of the radiator. The Galli-ator and Lincoln thermostats are heated by the water temperature and the Columbia both by the water temperature and by the air in the engine house, so that whichever temperature is greater will operate the device. The defect of water temperature regulation appears to be that the inside of the bonnet is still cold, in zero weather, with the water at 75°C. The defect of air temperature regulation only is that in zero weather the thermostat has to be adjusted to operate earlier as otherwise it will try so hard to maintain the proper temper-ature under the bonnet that it will allow the water to boil in the radiator. Perhaps the Columbia scheme is best, but we are un-familiar with this car. The great advantage of the Galli-ator scheme, or any scheme which only uses the thermostat as a controlling device, and some other function of the engine as the operating device, is that whatever the temperature of the engine, the shutters close as soon as the car stops. The Winterfront shutter has an attachment for closing it by hand when the car stops, but naturally the automatic device is better. We think this feature is most important for the States, because it shuts the warm air into the bonnet, whereas with any device which does not close until the water temperature has fallen, everything inside the bonnet is cold before the shutters close (crankcase, induction pipes, etc.). With regard to the position of the shutters, we believe that for the States these should undoubtedly be on the outside. The first reason for this is that in this way the heat is contained without a muff, when the car is standing. The Galli-ator with highly polished nickel-silver shutters, is said to contain the heat so well in cold weather that in practice the muff over the bonnet is not necessary except for very long stops, even in the coldest weather. (Contd) | ||