Another T-Stat Temperature Question

[Calan]

After installing my FMIC, my car was running hot... but with new fans, a lower air "scoop", and a better coolant mix, I was able to lower it considerably. It now runs around 206-216, but it's been cool here lately.

Well I've torn it down for a bunch of work and figured I'd replace the T-Stat while I'm at it. Since it gets over 100* often around here in the summer, what temp T-Stat would you recommend? Stock 190? 180? Lower?

Thanks

 

[oldman]

180.

 

[Defiant]

The thermostat is to keep the engine warm, and to restrict the flow of coolant. The radiator is to cool it. Your engine wants to run warm, and its control systems are calibrated for it. If you aren't cooling enough, the suspects are your radiator's effective capacity and the water pump's health.

 

[endeffect0]

Defiant makes a good point, if your car's cooling can't keep up you really should spend the extra bucks on a new rad getting a nice thick aluminum unit will really bring the temps down. if you want a really good fan check this out, http://www.ffwdconnection.com/spal.shtml a freind of mine uses that on a rotory powered AutoX car (which puts out as much heat as a small nuclear reactor) and it really pulls hard.

I personally take the thermo out of my dsm in the summer as its not a primary car at the moment so I'm not worried about giving the car a little extra time to warm up on start up. It actually makes quite a difference in my temp at idle after the car has fully warmed up because of how restricting the thermo is.

 

[Calan]

Yeah... I was thinking in terms of the T-Stat's restriction of flow, and if different temp ratings would affect cooling by having different amounts of resistance to flow. But if they all have the same flow restriction and just different spring values, then I understand Defiant's point.

 

[endeffect0]

Nope the temp rating on the thermos are for the temperature that it opens at. The spring in the thermostat is made of a metal that contracts to open the valve when it gets hot. They all will flow the same rate regardless of the temperature rating.
If you want to check and see how well the thermostat you have is working just take it out and put a pot of water on the stove with a thermometer in it. The thermostat should be fully closed from room temperature right up until it gets near its temperature rating where it should fully open in a few seconds.

Like I said previously if you want the maximum flow just remove the thermostat until the cold weather hits again (I'm hoping by now its over). Just keep an eye on your temp gauge and take it easy on the car till it warms up

 

[Defiant]

Nope the temp rating on the thermos are for the temperature that it opens at.

And, closes at.

The spring in the thermostat is made of a metal that contracts to open the valve when it gets hot.

A thermostat is actuated by the expansion of wax inside a capsule. The spring closes it.

They all will flow the same rate regardless of the temperature rating.

No, they're proportional.

If you want to check and see how well the thermostat you have is working just take it out and put a pot of water on the stove with a thermometer in it. The thermostat should be fully closed from room temperature right up until it gets near its temperature rating where it should fully open in a few seconds.

It's a dynamic device, and will adjust its opening along with varying temperature.

Like I said previously if you want the maximum flow just remove the thermostat until the cold weather hits again (I’m hoping by now its over). Just keep an eye on your temp gauge and take it easy on the car till it warms up

Removing a thermostat can lead to accelerated and turbulent flow, which can create hot spots around the hottest part of the engine, primarily the exhaust valve stems and guides whose only path of cooling is through the coolant. Intakes and pistons are cooled by incoming fuel/air, piston skirts have oil to carry off heat. Overheating around the exhaust valve guides can lead to flash boiling in the area, with the ensuing steam preventing most of the coolant from doing its job because it can't get through the vapor.
Don't run without a thermostat on a modern engine, and don't waver from the factory temperature ratings.