Thermostat Temp

[petertay]

Ford NAA heat gauge shows cool, even when the tractor has been run for a while. I put a thermometer in the radiator and the temp show 140. So the thermostat is stuck open. It will be replaced.
But my question is: Why does it matter (to the engine) if the heat is 140 or 180?

 

[John P.]

Obviously you don't want it to overheat, but the cast iron cylinders wear better with a higher temp. I go with either a 160 or a 180-degree stat.

 

[Bern]

Ford NAA heat gauge shows cool, even when the tractor has been run for a while. I put a thermometer in the radiator and the temp show 140. So the thermostat is stuck open. It will be replaced.
But my question is: Why does it matter (to the engine) if the heat is 140 or 180?

Hotter is better with regards to engine temps. Too cold and the oil starts to sludge. In addition, too much combustion heat is lost to the cooling system, which reduces fuel economy as well.

 

[Buffalo Pete]

The 160F temperature was based on using alcohol based anti-freeze back in the day. Higher temperatures would cause the alcohol to flash off. I put in a 185F thermostat and haven't looked back. The reason your gauge shows cool, is that there may not be a thermostat at all (someone removed it). I took my old one to NAPA, and they matched one up for it.

 

[Texasmark]

I run the hotter stats too. You really ought to check out whether or not you have a stat and have one installed. If you have one, the opening temp should be stamped into the bottom of the "pellet" on the stat. You check to see if you have one and if you do, and it is working, you can check the opening temp by putting a string under the plate that moves to open it and put it in a pan of water brought up to boiling temp with a candy thermometer monitoring the water temp. Suspend the stat in the water holding it up with the string. When it drops off the string check the temp on the thermometer.

 

[MarkB_MI]

Be careful when replacing your thermostat, as it's easy to break the housing. The thermostat mounts vertically and tends to slide out of its groove when you re-install the housing. If you tighten up the housing bolts with the thermostat out of place you'll break the housing. I take a length of fine wire or fishing line and loop it under the thermostat to hold it up while installing the housing, then pull it out once the bolts are finger-tight.

Running too cool is not a serious problem, but condensation tends to build up in the motor if it never gets hot. In general it's best for the engine to keep it at a fairly constant temperature, but below boiling. Your tractor uses a low pressure radiator cap, so it's best not to use a hotter than stock thermostat.

 

[petertay]

Mark, thank you for the suggestion in how to install it safely! —Peter