Cooling system operation (page 2 of 2)

The cooling system employed is the by-pass type, allowing coolant to circulate around the engine while the thermostat is closed.

When cold the thermostat closes off the coolant feed from the radiator bottom hose, which is fed via an engine oil cooler. Coolant is drawn via the heater matrix from the rear of the cylinder block (No.1 cylinder); this allows some heat transfer to the radiator via the top hose by convection while retaining the majority of the heat within the cylinder block.

As temperature increases the thermostat gradually opens, bleeding cool fluid into the cylinder block and allowing hot coolant to flow to the radiator via the top hose, balancing the flow of hot and cold fluid to maintain temperature. As the thermostat opens further so the full flow of coolant is drawn through the radiator.

The radiator is a copper/brass cross-flow type with moulded plastic tanks top and bottom which incorporate 2 sensor mountings. The radiator is mounted in rubber bushes directly into the front body member. The top of the radiator is mounted by means of mounting brackets bolted to the bonnet locking platform. For additional air flow, at times when the vehicle is stationary, an electric cooling fan is fitted. This is triggered by a thermostatic switch mounted in the radiator inlet tank.

The coolant pump is a rotor type drawing coolant directly from the thermostat and is driven directly from the power steering pump.

The engine has additional cooling provided by an oil cooler, coolant from the radiator cools the oil before it enters the oil filter which is fed via an oil thermostat.

As engine oil temperature increases the oil thermostat gradually opens, bleeding hot engine oil through the oil cooler allowing the cold coolant from the radiator to cool the engine oil which returns in a cool state to the oil pump via the filter element.