Oil cooler thermostats

[expat]

A frind wants to fit an Ait to Oil engine oil cooler to his car and will use a thermostat with this.

It seems most thermostats begin to open at 160f and are fully open at 180f.
This seems low. Why would 180f motor oil need to be cooled?

To me 240f would make more sense.

 

[ragtoplvr]

Because then your cooler would never be hot. People who are the type to install one would notice it never felt hot, and tell themselves I wasted that money.

Rod

 

[maxdustington]

Those thermostats might be made for transmission coolers.

 

[VeryNoisyPoet]

Most oil thermostats will allow a few percent flow when cold to bleed out air bubbles from the system and prevent thermal shock. As an example, the OEM oil thermostat on my car begins to open at 200F and is fully open by 300F. Under heavy load oil temps will stabilize at 250F to 270F, with temps 190F to 220F during highway cruising. Depending on size of cooler, the 180F thermostat may be alright, but a warmer temp range would be better for keeping moisture out of the oil.

 

[Snagglefoot]

Opening at 180 really means the oil temp might be way higher but as long as its above 180 it's going to be cooled. It might be at 240 F to start with high rpm driving.

 

[expat]

Originally Posted by Snagglefoot
Opening at 180 really means the oil temp might be way higher but as long as its above 180 it's going to be cooled. It might be at 240 F to start with high rpm driving.



But the t'stat begins to open at 160f and is fully open at 180f. To be that suggests the oil will never be allowed to get above 180f , assuming the cooler is of sufficient cooling capacity.

 

[Snagglefoot]

Originally Posted by expat
Originally Posted by Snagglefoot
Opening at 180 really means the oil temp might be way higher but as long as its above 180 it's going to be cooled. It might be at 240 F to start with high rpm driving.



But the t'stat begins to open at 160f and is fully open at 180f. To be that suggests the oil will never be allowed to get above 180f , assuming the cooler is of sufficient cooling capacity.


The cooler is not operating at maximum efficiency until the thermostat is fully open. It will try cool the incoming oil but the final temperature depends on the temperature of the incoming oil ( which is highly dependent on the rpm of the engine), the ambient temperature of the air running through the cooler and the velocity of the air through the cooler which is a function of fan speed and vehicle speed. These oil coolers are quite small compared to the coolant radiators so the final temp is probably somewhat higher than 180.