180 or 195 thermostat for compact gas tractor ?

JeepsAreBuilt · Mar 25, 2015

So.. I want to replace the thermostat in my IH 284 gas tractor. It has the Mazda gas motor, and I cant find a thermostat anywhere online for this thing. I did stumble across a thread where someone used a Napa part number XXX thermostat, which I did pick up, but did not fit. So, I went back, and was able to talk the guy behind the counter into letting me look though their thermostats to find one that fits. So, I picked out a Winner ! I hope, however its a 195 degree instead of a 180 that I pulled out of the tractor.

Would the tractor run too hot with the 195 ? Will my oil temp rise too much ? I have a electric fan(on a toggle switch) and a mechanical fan thats locked up(not clutch style).

Should I just get a 180 ? I figured out what vehicle the thermostat fits, and found they make a 180 as well..

tcartwri · Mar 26, 2015

What kind of use is the tractor for? Do you do sustained full power implement work, or the odd job here and there.

arrow · Mar 26, 2015

I do not feel you would be hurting a thing to have this stat retention figure. As long as you have a working fan against the radiator and your engine compartment is open, I do not feel any damage would ensue with the higher temp stat. If however it gives you piece of mind as it is available, just throw in the 180* stat

Here is my reasoning: Regarding on how a thermostat works in any engine, Lets say the vehicle's coolant under normal conditions runs at a max temp of 220* before over heat occurs. With any thermostat installed. So, with a 180* thermostat, once the car is started the coolant starts off at 0*. The coolant will start to rapidly increase in temp at first because it is static within the coolant flow path. Why? Because the thermostat is closed which does not allow it to move about and through its radiator to dissipate the heat. It will move slightly, but very minute from natural heat expansion and the small pass hole in the thermostat. So, if it takes it 5 minutes to reach 180* to relay that heat to the thermostat, which then opens which allows the water pump to move the coolant through its path and through the radiator to dissipate the heat. But overall the coolant will still reach a max temperature of 220*..
So, now lets replace that 180* thermostat with a 195* one. The steps proceed just like above. However, instead of reaching 180* in 5 mins to open the thermostat. Now, it must wait a extra few minutes until that coolant reaches 195* to open the thermostat and flow through the system. Again, the coolant will still only reach a max temperature of 220*. In other words, a stat acts more like a timer rather than a regulator of how hot an engine runs. Fans, radiator size, engine size, component material, engine load and air flow have much more to do with that than a thermostat.

JeepsAreBuilt · Mar 26, 2015

Thanks for the replies.

I just do odd jobs mostly I guess.. and alot of mowing. I do push the limits with my rototiller in the garden.

I went ahead and threw the 195 t-stat in, I think you are right.. and 15 degrees wont KILL me. Also, I drilled a 1/8" hole at the top of the t-stat flange to allow some water to pass or air bubbles. It works just fine.. spent about 1/2 hour with the bush hog cutting grass and some black berries.

JeepsAreBuilt · Mar 26, 2015

Thanks for the replies.

I just do odd jobs mostly I guess.. and alot of mowing. I do push the limits with my rototiller in the garden.

I went ahead and threw the 195 t-stat in, I think you are right.. and 15 degrees wont KILL me. Also, I drilled a 1/8" hole at the top of the t-stat flange to allow some water to pass or air bubbles. It works just fine.. spent about 1/2 hour with the bush hog cutting grass and some black berries.