whats the best coolant temp.

[dew34]

As the title states what is the best running coolant temps for the 2.3 T . I did a t-stat change after buying the car and noticed that it had a 180 stat the replacement stat was a 192 .It always seemed to run a little on the warm side with the 192. I am not having cooling issues was just wondering what is the ideal coolant temps with this engine.
mike

[MikeFleming]

The higher the coolant temp, the better the heat transfer & the better the cooling (removal of heat from the engine). At a minimum the coolant should get the engine oil hot enough to boil off any moisture and fuel residues that get into the oil. The oil needs to reach at least 210 F (assuming a properly functioning PCV system. There is also less friction at higher temps.

In order to handle high temps the cooling system needs to be capable of holding pressure at temp (all hoses, connections, tubes, radiator, heater core, etc.) If it won't hold pressure, it will not reach the high temps before boil-over. Additionally a proper coolant [mixture] is also required.

Note that the thermostat only determines minimum temp - NOT max temp.

Stick with the stock 192 thermostat and make sure the rest of your cooling system is up to snuff (for various definitions of "snuff").

[dew34]

Thanks Mike the cooling system is up to the task. The radiator is a 2 core with 1 inch tubes aluminum radiator with a mix of water wetter, & coolant mix and very large fan. With the adjustable fan control i have no problems cooling the engine off.Right now i have the fan set to come on at 195 and off at 185 which now i see is too cool. I am going to adjust it to 205 on and 195 off . I know oil temp and coolant temps run very close .I do a lott of data logging with large diesels and notice that oil temps run 5-10 degrees + or - of the coolant temp. depending on the type of oil cooler. We like to see coolant temps in the 205-210 range How good is the 2.3 T oil cooler at keeping the oil temps in check or at least in line with the coolant temps.
mike

[MikeFleming]

Let's talk in a but more in-depth about cooling system design and temps.

In the typical Ford 2.3L OHC engine: Cold (assuming a cold start) coolant flows out of the bottom (left) of the radiator to the water pump. The pump pushes it through the lower portion of the block past the cylinders. Then it goes up through the rear of the block into the head and moves forwards through the head past the posts and spark plugs towards the thermostat (mounted on the front of the head). Picking up heat all along the way. When the thermostat is closed the total amount of liquid circulating is about one gallon. Some coolant is allowed to bypass the thermostat housing and recirculate to the engine so the coolant keeps moving the heat around to help warm up the engine faster. Heating up one gallon takes much less time that heating up two.

Then once the coolant reaches a specific temp it causes thermostat to open which allows some of the hot coolant from the engine into the top/right side of the radiator while at the same time allowing an equal amount, hopefully, of "cold" coolant back into the water pump. Ideally the thermostat slowly allows the "cold" coolant to flow in to not cause any thermal shock from introducing too much 75 F coolant to the ~200 F temp stuff currently flowing around in the engine.

Eventually the coolant temp in the radiator stabilizes and all the coolant becomes about the same temp. Note that the amount of coolant circulating at temp is now about 2 gallons.

In an ideal radiator system the coolant entering the radiator will be about 200-220 F. The coolant leaving the radiator should be about 165-185 F. A fan can easily be connected to control the radiator outlet temp to within that range.

So the fan should control the radiator outlet temps, NOT the temp of the coolant inside the engine. That later function is up to the thermostat - by controlling the amount of the cooler radiator coolant that is constantly exchanged with the hot coolant leaving the engine.

Note that the above numbers are for street cars. Most race cars (road race, NASCAR, etc.) use much higher temps and pressures. NASCAR engines run in the 50+PSIG of coolant system pressure. Most street cars use 16 PSIG or less. Drag cars are an entirely different breed. Rear drag cars even have coolant systems and they only run for 30 or so seconds at a time.

IMHO one of the downsides to this engine design is that the head gets cooled last - the coolant is already hot by the time it even gets to the exhaust ports.

BTW - the oil/coolant heat exchangers on these engines do a very good job. They also help warm up the oil faster as the coolant heats up. Ford used this same cooler on all their police package v-ate cars.