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).
Promotional leaflet for the R.P. Adjustable Thermostat, an aftermarket device to control engine temperature.
| Identifier | ExFiles\Box 156\1\ scan0008 | |
| Date | 10th May 1929 guessed | |
| Page 4. Why you should use the R.P. Adjustable Thermostat WHEN starting a run on your car you have probably noticed that the engine is sluggish, and also that this sluggishness is more acute in cold weather. This is due to lack of sufficient heat in the cooling water, resulting in high petrol consumption, loss of power, poor acceleration, flat spots and rough running, etc. The average engine gives best results when the cooling water in the Cylinder Block is at a temperature of between 80° C. and 95° C., and if, for example, your engine operates best at 90° C., it is obvious that it should always be run at this temperature, and further, THIS CORRECT RUNNING TEMPERATURE SHOULD BE OBTAINED IN A FEW MINUTES AFTER STARTING UP. Radiator shutters represent an attempt at solving this problem, but, in practice, are only capable of partial control, for the following reasons :— (A) The engine takes longer to warm-up because all the cooling water has to be heated. (B) The higher and more efficient running temperatures cannot be employed with safety, there being no reserve of cool water in the radiator, due to the fact that both radiator and cylinder block are at the same temperature. (C) The hand-operated type requires continuous attention on the part of the driver, and if not carefully attended to, all the advantages of correct running temperatures are lost. The R.P. Adjustable Thermostat fits in the top hose pipe between the engine and the radiator. This position, as the thermostatic element controlling the valve is in actual contact with the cylinder block water, is therefore capable of responding to the slightest temperature variation. THE TEMPERATURE IS CONTROLLED ONLY IN THE CYLINDER BLOCK, ENSURING A RESERVE OF COOL WATER IN THE RADIATOR, AND ENABLING THE MOTORIST TO EMPLOY TEMPERATURES UP TO 95° C. (boiling point 100° C.). Thermostats hitherto employed and fitted in the top water hose pipe are merely warming-up devices, that is, they warm the engine to a moderate temperature but do not control or maintain correct temperature under running conditions. THE R.P. ADJUSTABLE THERMOSTAT COMPLETELY SOLVES THE PROBLEM OF TEMPERATURE CONTROL, AND AT LAST MOTORISTS ARE PROVIDED WITH A CHEAP AND RELIABLE FITTING WHICH CAN BE ADJUSTED AND SET SO THAT THE TEMPERATURE OF THE WATER IN THE CYLINDER BLOCK IS MAINTAINED CONSTANT WITHIN 2 OR 3 DEGREES IRRESPECTIVE OF WEATHER CONDITIONS, AND AT THE RUNNING TEMPERATURE BEST SUITED TO THE PARTICULAR ENGINE. A special feature is adjustment, which is employed in order that the thermostat may be set so as to secure best results from any given engine. In addition, as during hot weather a setting for winter temperature unavoidably produces a greater amount of heat owing to the radiator water being at a higher temperature, the motorist may then set the thermostat for a decreased temperature. Two adjustments per year only are necessary, that is, during winter and summer. An adjustment takes about one second. A further feature is the full-open position, whereby the valve in the thermostat may be turned full-open, so that the thermostat is completely out of action. This full-open position is necessary :— (1) During extremely hot weather or mountain climbing. (2) To prevent air-locks when re-filling the radiator after it has been completely emptied. (3) In the event of accidental shortage of water resulting in the thermostat not being fully submerged. MANUFACTURED BY— The R.P. Adjustable Thermostat Co., Ltd., 195, STRAND, LONDON, W.C.2. 'Phone: City 3263 (3 lines). Telegrams: "Tempstat, Estrand, London." [Right Side] NO MORE COLD ENGINES! THE PROBLEM SOLVED AT LAST BY THE R.P. ADJUSTABLE THERMOSTAT (PATENTS PENDING) An Epoch-making device which AUTOMATICALLY CONTROLS THE WORKING TEMPERATURE OF YOUR ENGINE. Inserted in 15 Minutes You can adjust it externally up to 95° centigrade, enabling you to run your engine at its best temperature winter and summer. Engine attains correct temperature in 2 or 3 minutes after starting-up and remains constant irrespective of weather and speed. NEVER TOO COLD IN WINTER, a reserve of cool water in radiator in summer. Holds the heat in the cylinder block when the car is stationary. Run your engine at its most efficient temperature winter and summer. The “R.P.” Adjustable Thermostat is the only correct engine temperature controller on the market. | ||