I am not a supporter of the PTR, because what makes the PTR is to mix the hot coolant with the cold, to establish a steady coolant and balanced, but that always come enter in the engine to the temperature not desirable, more hot.
If we put a PTR not take advantage of the radiator, because mix the coolant cold with the hot and that is a mistake.
When coolant comes from the radiator, is more cold and the mixture with the hot, that is what makes the RTP to approximately 85 degrees, this coolant enters balanced, but more than normal temperature.
I suggest a good thermostat, the lower the better, so that the hot and cold coolant enter in contact as soon as possible and do not occur in large dilations in the aluminum of the block and piston head.
And put other coolant temperature sensor auxiliary for the fan, so that start work approximately to 85 degrees.
Thus coolant never arrive at approximately 103 degrees and never work the coolant temperature sensor that is to the exit of the piston head, because the coolant never arrive more than 87/90 degrees.
This is an easy job, just put a piece in the form of a “T” for the coolant passes through it and at one end placing the new coolant temperature sensor.
This new coolant temperature sensor, detects when the coolant is to 85 degrees approximately, and it will be responsible for moment of work of the radiator fan and thus solves the problem for those engines that no have a ECU that can regulate the time working fan.
If you delete the thermostat, the coolant will heat more that if you has a thermostat, because the coolant circulates to much speed into the circuit, the radiator does not have time to cool the coolant.
The thermostat hare of brake within the coolant circuit and only let pass the high volume of coolant, when this is heated.
The opening of the thermostat is gradual, depending on the temperature of the coolant, open more or less.
surely thermostats are there to regulate the temperature of the engine, maintaining it at/near an optimal operating value eg 82C. By removing the thermostat you’ve lost this control, hence your engine will usually be operating at too low a temperature - in exceptional circumstances this will reduce engine bhp as the oil will be thicker. I however think the idea of the PRT is good as it allows the system to bleed cooler coolant into the system without dramatically reducing the engine coolant temperature i.e. less heat shock. Over to you…
If you delete the thermostat, the coolant will heat more that if you has a thermostat, because the coolant circulates to much speed into the circuit, the radiator does not have time to cool the coolant.
The thermostat hare of brake within the coolant circuit and only let pass the high volume of coolant, when this is heated.
The opening of the thermostat is gradual, depending on the temperature of the coolant, open more or less.
Regards
Not sure about this - by your reasoning the coolant will also pass through the engine a lot faster picking up less heat…
… because the coolant circulates to much speed into the circuit, the radiator does not have time to cool the coolant…
This is a common misconception. If the water goes though the radiator faster it will transfer more heat because the heat transfer coeficient is improved due to the higher velocity.
If you remove the thermostat completely the engine will run far too cold, probably about 40 - 55 �C this time of year. This is because there will be too much flow in the radiator circuit.
It is possible that in your country, occurring that the coolant does not exceed the 40/50 degress, but in Spain more than 45 degrees of ambient temperature in the summer, if delete the thermostat, the coolant temperature will arrive to more degress during the work the engine, that if it is put.