is there a thermostat that can be used with one of these systems ? and are any of them using one? seems like it'd help . ; if there were a resevoir .

 

Why do you say a thermostat would help?

 

uh . why do they put them on regular cooling systems? to 1 keep the coolant in the block till it comes up to temp and 2 to keep it in the radiator longer so it will stay at that temp . seems with these systems a thermostat would hold the coolant in the radiator longer . the pump would require a pressure switch or bypass or some equivalent but it could be done . or maybe it's not necessary as the radiator is bigger than needed . just asking why .

 

There is no thermostat in my air/water intercooler, you don't need one. My pump runs about 3 minutes even after the car is off. The intercooler system works much different than a cars radiator. The key to the intercooler is "the colder the better".
M

 

see; that's just it with a regular system the thermostat will keep the coolant in the rad. to cool it ; plus it has a fan . this is why cars aren't running around with heat soaked blocks , getting hotter and hotter . maybe it's not cost effective .

 

No, the thermostat in a car's cooling system exists to maintain a *minimum* coolant temperature in the block. If the thermostat is closed, it's not to keep the coolant in the radiator for extra cooling - it's to keep the coolant in the engine block to allow it to warm up.

Here's an example. Let's say that you have a 180F thermostat. When you start the car for the first time of the day (everything at ambient temperature), some of the coolant is in the block, and some is in the radiator, and those two quantities of coolant are kept separated by the *closed* thermostat. As the coolant that's already in the engine warms up to 180F, the thermostat opens and allows it to mix with the coolant in the radiator. Once the engine's up to operating temperature, the thermostat stays *open* for the rest of the trip, unless the coolant temperature starts to drop below 180F. When that happens, the thermostat starts to close again, not to provide extra cooling for the coolant in the radiator, but to allow the coolant in the block to continue to recirculate through the block to warm back up.

This is why if you have a thermostat that's stuck open, the car takes forever to warm up and may never reach normal operating temperature. Running around without a thermostat doesn't result in a heat-soaked block - it results in too-low coolant temperatures. The extra flow restriction from the thermostat (even when fully-open) *does* help the cooling somewhat by slowing down the coolant as it passes through the radiator, but that's a secondary effect. The primary purpose of the thermostat is to keep the coolant temperature *above* a certain limit.

With a water-to-air intercooler, installing a thermostat to keep the intercooler water in the radiator longer would also keep the already-warm water around the intercooler from circulating out of the intercooler, which is the last thing you want.

 

scott- If you keep this up I think I can pass my mechanic/physics college level education just by reading your posts.

 

A NAM membership has it's advantages!

 

Thanks - I'm currently taking my Master's-level mechanics course, and thermodynamics is next quarter. I'm amazed both at how much I'd forgotten from my udergraduate days in the late 80's/early 90's *and* by how quickly it's all coming back with new exposure.

 

Physics is all fun and sweet subject. I was aways drawn to it and wanted to learn more and explore.

 

so to avoid heat soak all you can do is slow down the coolant or add a bigger resevoir?

 

I'm assuming you're talking about cooling a water-to-air intercooler, and not the car's cooling system.

Slowing down the water will mean that it will spend more time in the intercooler system's radiator cooling down, but it also means that it will spend more time in the intercooler getting heated up. Your other options include a larger reservoir, filling the reservoir with colder water (like ice water, although this is more-appropriate for track days), or increasing the cooling capacity of the intercooler system. You could do this by splicing a transmission cooler into the return line from the intercooler, preferably placing the tranny cooler in the airflow under the car. The transmission cooler gives you an additional radiator, and many of them have electric fans as well.

The cooling fluid makes a difference as well. If you mix in some "Water Wetter" or similar surfactant, it will reduce the surface tension of the water, allowing for better heat transfer out of the water while it's in the reservoir or cooling radiator, as well as better heat transfer *into* the water while it's in the intercooler.

This is one of the limitations of a water-to-air intercooler. Unless you add ice to the water or something like that, you'll never get the water below ambient temperature, and if it gets significantly warmer than ambient, it can take a while for such a large mass of water to cool off again. But as long as the intercooler water is still cooler than the intake air flowing through the intercooler, it will still pull heat out of the intake air - just not as quickly.

 

uh...you want a regular engine coolant system to come up and maintain a minimum operating temp (temperature rating on the thermostat). On an IC coolant system you want it operating at the lowest possible temp for the densest charge. NO THERMOSTAT. Ideal temp would be just above freezing so you don't end up icing up the intake. (obviously not going to happen)

 

Water won't cool with any significance in a reservoir. It has to be in the radiator (ambient air/water) to cool.

What are the typcal IATs that you are trying to cool down from?

 

Thanks for catching the typo - I'l fix it in the original post. Although I guess with the right reservoir (large surface area, in the air stream, large amount of water, made out of something like copper that conducts heat well, you might even be able to get away without a dedicated radiator.

 

That would only work if you have good circulation (mixing) within the tank to ensure that the water is exposed to the sidewalls of the reservoir. You'd be better off replacing the reservoir with a heat exchanger of the same external dimensions if you had it in an area with cool airflow. A reservoir is only useful for make-up coolant. Not necessary if you don't have any leaks, and not critical in an IC application where an empty system will just reduce performance rather than destroy the engine.

 

so, lets say that you place the heat exchanger for the wta inside the car where the a/c is blowing very cold air over the unit. yes i know that in the extreme hp mode the a/c is turned off, but could the gains outweigh the losses due to temp reductions. would this provide anything like "icing"it down? jmho

 

The A/C just chews up too much power.

 

so an additional radiator in the back where the drivers' side muffler used to be would be cool .

 

You can get a minute amount of cooling from a reservoir, just nothing Earth shattering. Porsche used to do that with their air/oil cooled engines by making the dry sump oil tanks out of copper. Dropped the oil temps a couple more degrees, but it was an expensive couple of degrees.