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).
Leaflet detailing the features, operation, fitting instructions, and price of the 'R.P.' Adjustable Thermostat.
| Identifier | ExFiles\Box 156\1\ scan0009 | |
| Date | 2nd February 1929 guessed | |
| Page 2. INSTANTLY ADJUSTABLE AT WILL OF OWNER TO ENSURE CONSTANT CORRECT RUNNING UNDER ALL CLIMATIC CONDITIONS. Page 3. THE “R.P.” ADJUSTABLE THERMOSTAT. FITTING INSTRUCTIONS. THERMO-SYPHON. Drain Radiator. Remove Rubber Hose from between top of Radiator and Cylinder Block. Cut Hose into two lengths. Fit “R.P.” Thermostat in the Rubber Hose as closely as possible to the Cylinder Block. PUMP CIRCULATION. In the case of Pump Circulation, it is necessary to connect a Rubber Circulation Pipe between the Branch-piece on the “R.P.” Thermostat and the bottom hose pipe as closely as possible to the suction side of the pump (see illustration). With the “R.P.” special cutter and connector this connection is made in two or three minutes without removing anything. The extra cost (5/-) for pump circulation includes the “R.P.” cutter, the two “R.P.” connectors, and a length of “R.P.” special canvas ply hose. The valve should be closed during fitting operation. Note. Fit Thermostat preferably with thermometer branch in horizontal position and parallel with radiator. ADJUSTMENT INSTRUCTIONS Having fitted the thermostat, fill the radiator, first making sure that the valve is turned full open, in order to prevent air locks. Then set the pointer on the knob in the centre of the “Correct Temperature” range indicated on the dial. This setting is approximately equivalent to 85º C., and will be found correct for the average engine. Should this setting be either too high or too low, it is a simple matter to modify the temperature by turning the knob in the increase or decrease direction, as indicated on the knob. Each graduation within the “Correct Temperature” range increases or decreases temperature 3 to 5 degrees centigrade. For temperatures above 85º centigrade it is advisable to operate in conjunction with the “R.P.” Dashboard Thermometer, which fits into the “R.P.” Thermostat and indicates the exact temperature of the water in the Cylinder block. The external adjustment on the “R.P.” Thermostat ensures correct engine temperature Summer and Winter. The outstanding feature of the “R.P.” Adjustable Thermostat, (the ONLY ADJUSTABLE Thermostat on the market) is correct Water Temperature Control, made possible by means of the simple external adjustment which enables the motorist to set the thermostat to start operating at any specific point up to 90ºC., thus ensuring Correct Temperature. The valve remains closed until the pre-determined set temperature is attained in the cylinder block; thus correct working temperature is obtained in 2 or 3 minutes after starting up, and thereafter under touring speeds this temperature is maintained constant within 2º C. even in the coldest weather. The knob on the outside of the fitting serves a dual purpose :—It adjusts the temperature, and also enables the valve to be turned permanently full open, for exceptional conditions such as—very hot weather, accidental water shortage or mountain climbing. HOW IT WORKS. The Butterfly valve in the body of the “R.P.” Adjustable Thermostat is operated by a coil spring made of thermostatic metal. Under the action of heat, this spring winds and unwinds—thus opening and closing the Butterfly Valve. PRICE Thermo-Syphon - 28/6 Pump Circulation - 5/- extra (For details of outfit see page 3). When ordering state :— (1) Outside diameter of top rubber hose (i.e., between cylinder block and top radiator). (If possible state inside diameter of rubber hose). (2) Whether Pump or Thermo-Syphon water circulation. (3) Make, H.P., and date of manufacture of car. “R.P.” CONNECTOR. By a few turns of Milled Disc the Rubber Plug on connector expands inside the pipe after insertion in hole bored by “R.P.” cutter, ensuring permanent watertight joint. THE SAME RUNNING TEMPERATURE SUMMER AND WINTER A RESERVE OF COOL WATER IN THE RADIATOR IN SUMMER Image Labels: Direction of flow Cap Nut to be removed when Dashboard Thermometer is used. Thermostatic Spring element Special fabric seating. Indicator Dial Temperature Adjustment and Full Open Knob Branch place housing for “R.P.” Dashboard Thermometer. The R.P. Adjustable Thermostat RADIATOR CYLINDER BLOCK Circulation Pipe R.P. Connector Lower Hose Pipe. Pump | ||