Hello all,
With a liquid cooled engine, the thermostat allows the engine to reach it's operational temperature as quickly as possible and to maintain it under all operating conditions.
This is particularly important for the service life, the fuel consumption and the exhaust gas development of the combustion engine.
The temperature of the coolant increases, from its entry into the cylinder block, until it reaches the cylinder head.
The liquid cooling should take up the engine heat through the coolant, and release it, through the radiator, into the open.
The engine temperature should ideally be very constant, the circulation pump cooling helps to avoid component-critical temperatures in all parts of the engine.
Also the cylinders which are not in the vicinity of the pump, are cooled to the same extent.
In my opinion it's not a good idea closing the single coolant circuit with a closely tight thermostat, specifically by a cold motor.
The opening temperature of thermostats is determined for the respective cooling system, the temperature was previously set at 80°C, nowadays 90°C and more are achieved. - remember, in modern cars we have a primary and secondary coolant circuit -
The only way, without changing the shape of an old motor, is using a thermostat with a short circuit.
( e.g bypass, hole, gap in the thermostat - >> controlling the motor temperature by coolant flow and not by conduction of heat ! )
Thus prevents, if using a thermostat in a single circuit cooling system, the sudden cooling down of one or more cylinders and avoid component-critical temperatures in all parts of the engine.
Have a nice day
