Thermostat or no thermostat.

[Super6]

I have never heard of Evans coolant? Doe's it drop temperature's quite a bit over regular antifreeze in a cooling system?

Evans Cooling Systems - High Performance Engine Cooling and Power Production. i haven't really seen a temp drop but the boiling point is like 375 degrees and that is why i am using it. my car stays at 160 degrees riding around. it gets to 170-175 on a full 1/4 pass on a hot day.

no bandaid here....dual fans,big aluminum radiator.Evans recommends you don't use a thermostat.............Bob

 

[zues1]

water wetter

a friend of mine uses this in his outlaw camaro we race 632ci nos motor doing nothing else but adding water wetter drop temps over 20* in temps i was very empressed i think you can get it at any local part store

 

[GNeric]

Exactly. There is nothing to stop the water and hold it in the radiator to cool it down then swap with the heated water in the block. Without it, it just keeps getting hotter and hotter. You can maybe run a restictor but I would go with a thermostat designed to run at one certain temp. I have a front mount in my car and with the F-body radiator and dual fans, the temp never gets above 183ish in heavy traffic with A/C on in the summer.

X2 We tune our cars to run on the temperature that our thermostat keeps the engine. Without one the engine temp will rise or lower more according to the outside temperature which in turn will keep you constantly tuning. I have heard of pulling a thermostat before and the water pump actually circulating the water to fast and not give the radiator sufficient time to cool the water down. Just my 2 cents.

 

[sabersaw30]

Exactly. There is nothing to stop the water and hold it in the radiator to cool it down then swap with the heated water in the block. Without it, it just keeps getting hotter and hotter. You can maybe run a restictor but I would go with a thermostat designed to run at one certain temp. I have a front mount in my car and with the F-body radiator and dual fans, the temp never gets above 183ish in heavy traffic with A/C on in the summer.

If you are running a 160 stat it stays open all the time anyway once it gets hot I see no difference.Back with the older muscle cars nobody run a stat.And there cars stayed cool.Probably a little different on computer cars though.

 

[BlackBandit]

If you are running a 160 stat it stays open all the time anyway once it gets hot I see no difference.Back with the older muscle cars nobody run a stat.And there cars stayed cool.Probably a little different on computer cars though.

If by open you mean all the way open then the above isn't true. The only time your T-stat stays open all the time is when it either malfunctions or the cooling system can't keep up. Another thing about a t-stat is that even when it's open it acts as a restriction. Restricting the water flow allows the radiator to cool the coolant down below the temp of the stat so that as the temp of the coolant behind the stat climbs above it's set temp it can open and allow enough cold coolant in to lower the coolant temp enough to close the stat. It's an important part of a working cooling system and it's no different on computer controlled cars. The only real thing the ECU does is control fan turn on/off temp and that's probably more of an emissions deal. (to heat the car up faster and control load on the electrical system)

 

[xrunner123]

Aside from regulating temperature, the thermostat also has a built in restriction but it's a common misconception about reducing flow to help cool. Keeping fluid longer in the radiator to help cool is completely false. No offense to anyone but if someone can prove me wrong please enlighten me.

The restriction helps to build pressure on the back side of the thermostat (the engine) which is where you want it. This stop steam pockets from forming inside the engine.

 

[GNeric]

Just my opinion but lets say you get your car up to 213 degrees and with the fan on. Turn your engine off so there is no coolant flow. Use an infrared theremometer and check temps across the the radiator. Turn the fans on and watch the temp change while the coolant in the block either stays the same or heat soaks a bit. Been there done that to show a friend what happens. Not scientific and no data sheets to show but try it and see what happens.

Cool attracts heat. Reason for soda cans to sweat when hot out. Condensation on an accumulator when A/C is working.

 

[xrunner123]

Just my opinion but lets say you get your car up to 213 degrees and with the fan on. Turn your engine off so there is no coolant flow. Use an infrared theremometer and check temps across the the radiator. Turn the fans on and watch the temp change while the coolant in the block either stays the same or heat soaks a bit. Been there done that to show a friend what happens. Not scientific and no data sheets to show but try it and see what happens.

Cool attracts heat. Reason for soda cans to sweat when hot out. Condensation on an accumulator when A/C is working.

Listen to what you're saying. For the best cooling one should turn off your water pump? This logic makes no sense. BTW, The soda can sweats because the surface is below the dew point temperature. No humidity in the air and no sweat regardless of outside temperature. :wink:

This is a CLOSED system. The object is not to cool what's in the radiator but what is near the heat source. If you're trying to cool beer then yes you want your water flow to go slow. In goes hot out comes cold. If you slow down your flow in the radiator the delta T inlet vs outlet will be much greater but so will your coolant in the block.

Water flow or air flow uses the same equations for heat transfer. Would you block air flow to the radiator to cause the air molecules to stay in contact with the surface longer? No you would increase airflow. Same for water

Heat removal is directly proportional to air/water flow. Period. Q=m*Cp*deltaT. Q=heat,m=mass flow,Cp=specific heat, deltaT=temp difference between radiator inlet and outlet . Increase flow and deltaT goes down. Add more heat to the system and delta T goes up. The same equation holds true to the airflow across the radiator- more air flow= more heat removal.:biggrin:

 

[GNeric]

I am talking about what you said about keeping fluid in the radiator longer. Almost the same affect. Thermostat shuts, flow to radiator is null if barely there at all. You still have bypass built in (heater core). I know there is pressure built in the system but it is not because of the thermostat. It is from the cap. There is still equal pressure on both sides of the thermostat. There won't be 18psi on the pellet side and 16psi on the waterneck side. Relief in cap determines that. This is what my point is.

Aside from regulating temperature, the thermostat also has a built in restriction but it's a common misconception about reducing flow to help cool. Keeping fluid longer in the radiator to help cool is completely false. No offense to anyone but if someone can prove me wrong please enlighten me.

The restriction helps to build pressure on the back side of the thermostat (the engine) which is where you want it. This stop steam pockets from forming inside the engine.

 

[BlackBandit]

Aside from regulating temperature, the thermostat also has a built in restriction but it's a common misconception about reducing flow to help cool. Keeping fluid longer in the radiator to help cool is completely false. No offense to anyone but if someone can prove me wrong please enlighten me.

The restriction helps to build pressure on the back side of the thermostat (the engine) which is where you want it. This stop steam pockets from forming inside the engine.

The pressure in the cooling system is pretty constant across the entire system. Think series electronic circuits. The pressure in the system has absolutely nothing to do with the t-stat and everything to do with the radiator cap and the basic physics involved with heating liquid.

Listen to what you're saying. For the best cooling one should turn off your water pump? This logic makes no sense. BTW, The soda can sweats because the surface is below the dew point temperature. No humidity in the air and no sweat regardless of outside temperature. :wink:

This is a CLOSED system. The object is not to cool what's in the radiator but what is near the heat source. If you're trying to cool beer then yes you want your water flow to go slow. In goes hot out comes cold. If you slow down your flow in the radiator the delta T inlet vs outlet will be much greater but so will your coolant in the block.

Water flow or air flow uses the same equations for heat transfer. Would you block air flow to the radiator to cause the air molecules to stay in contact with the surface longer? No you would increase airflow. Same for water

Heat removal is directly proportional to air/water flow. Period. Q=m*Cp*deltaT. Q=heat,m=mass flow,Cp=specific heat, deltaT=temp difference between radiator inlet and outlet . Increase flow and deltaT goes down. Add more heat to the system and delta T goes up. The same equation holds true to the airflow across the radiator- more air flow= more heat removal.:biggrin:

You're right about the soda can.

You're wrong about the flow. If you take the time to actually work out your equations you'd see that. The less time a medium spends in contact with another medium the less transfer of energy you'll have. It's pretty simple. lets assume a car is going 50 mph. The airflow across a radiator is constant at 50 mph. That means the only thing you can change is flow through the radiator. The faster you flow coolant through the radiator with airflow being constant the less it will cool off. Same with the engine, the faster the coolant travels through the engine the less heat it absorbs. It's kinda junior high stuff really.

 

[moose]

After all that's been discussed on this subject i am still sticking to my gun's on running a thermostat is better than not, due to the fact that every car manufacturer i've ever known of has alway's put them in every car that has rolled off the end of their assembly line's. I find it hard to beleive that the one's who actually designed and built the cars we drive put thermostats in them because it ("wasn't necessary'?) I By no mean's know it all but if it look's like a peach, fuzzy like a peach, smell's like a peach, and tastes like a peach, It's got to be a peach!!!

 

[xrunner123]

Ok don't believe me. I guess I can't explain it well. Here are some quotes from Stewartcomponets. It looks like they’ve been in the system cooling industry for over 25 yrs. I think they would know. Give them a call maybe they can explain it better.


Stewart Components - High Performance Automotive Cooling

"A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However the cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot spots", which can lead to failures.Years ago, cars used low pressure radiator caps with upright-style radiators. At high RPM, the water pump pressure would overcome the radiator cap's rating and force coolant out, resulting in an overheated engine. Many enthusiasts mistakenly believed that these situations were caused because the coolant was flowing through the radiator so quickly, that it did not have time to cool. Using restrictors or slowing water pump speed prevented the coolant from being forced out, and allowed the engine to run cooler. However, cars built in the past thirty years have used cross flow radiators that position the radiator cap on the low pressure (suction) side of the system. This type of system does not subject the radiator cap to pressure from the water pump, so it benefits from maximizing coolant flow, not restricting it."


Stewart Components - High Performance Automotive Cooling
"Higher coolant flow will ALWAYS result in higher heat transfer. Coolant cannot absorb heat after it reaches it's pressure corrected vapor point. Furthermore, coolant absorbs heat at a progressively slower rate as it approaches this point."

"The radiator becomes less efficient as the coolant outlet temperature approaches ambient. Therefore, a low flow rate keeps the coolant in the radiator longer. The longer the coolant stays in the radiator the lower the efficiency of the radiator. "

 

[BlackBandit]

You're taking what they said to an extreme. Obviously the closer to ambient the coolant becomes the less heat transfer there is. That's a no brainer. The thing you don't seen to get is there's a balance. You don't want to the coolant to flow to quickly through the radiator OR the engine. The thing is, just like coolant approaching ambient doesn't get cooled as much by the radiator, the coolant that's approaching engine temp doesn't cool the engine as efficiently. Like I said, it's pretty junior high.

I'll re-state. If the radiator is up to the task it will have to coolant cold enough that the t-stat only opens up long enough to get the coolant temp to where it's set and then it will close. This will allow the radiator to do it's job and keeps engine cooling efficient.

Then again, maybe I'm wrong. In that case go ahead and and patent your idea and tell every auto manufacturer in the world that they're screwed up and it's going to cost them buku bucks to fix their screw up because you own the patent.

 

[Super6]

xrunner123

this is how Evans explains it or this is how i understand it specifically for a turbo car. Detonation is a hot spot so it is good that the coolant keeps flowing to take the heat away. the evans has a higher boiling point so it doesn't burn off in that hot spot and takes the heat back to the radiator to cool it down. Evans recommends a high flow water pump and a radiator that is up to the task for maximum cooling. my fans keep my temp down as they cut on appox 160 degrees and off around 155 degrees. Just riding around on the street the car does great as far as the temps so i am going to leave it out..every car is different though and everyone has their own opinion...hth...Bob

 

[rodman99999]

According to that logic, running a faster radiator fan and moving the air too fast will not give the air molecules sufficient time to cool the radiator down. Heat removal is proportional to mass flow. Faster flow is equal to more heat removal. That's why they make high flow water pumps. With that being said though, the thermostat is used to regulate the water temp at an optimal temperature.

The faster air moves over a surface, the faster heat is removed. (Forced Air Cooling and Fan Technology) It's not "logic", it's physics/thermodynamics. A liquid has to be in one place(like your radiator) long enough to have the heat removed from it. That's not rocket science.

 

[billygeg]

I know this is an old thread, I found it because I am debating on whether or not to run without a stat...I have listened to both sides of the arguments and I tend to agree with those that say running without one will do no harm..If your using a stat yes the radiator will have more time to cool the water in it as opposed to running without one but at the same time the coolant sitting in your motor is rising in temperature during that period till the stat opens again....So to me its 6 of 1 and half dozen the other..In other words its the same thing to me..Free flowing water will keep your radiator from cooling as well because its not sitting in there long but at the same time its keeping your engine water temperature from rising because its not sitting in there long..So Whats the difference? As for the argument that they put thermostats in a car for a reason..Yes they do..Its to provide hotter water to your heat core for better heat in the winter..I drive my car only in the summer so Im going to pull it and see what happens..If this thread ignites again, I will post what I find..

 

[BADDGUY6]

As for the argument that they put thermostats in a car for a reason..Yes they do..Its to provide hotter water to your heat core for better heat in the winter.

And faster/shorter warm up time?

 

[haywire4130]

If youre running a lockup converter it will lock/unlock as the coolant temp rises above/falls 150ish degrees, this is aggravating on the highway on a day when its cool enough outside for the radiator to overcool. I reckon eric could remove this feature if you insist on running without a stat.

 

[earlbrown]

.If your using a stat yes the radiator will have more time to cool the water in it as opposed to running without one but at the same time the coolant sitting in your motor is rising in temperature during that period till the stat opens again....So to me its 6 of 1 and half dozen the other..In other words its the same thing to me..

Actually it's not the same. Making the water go slow 'so it can have more time to cool' is way wrong for more than one reason.


Your reasoning is off because they are not the same. The heat rejection in the radiator is being moved into air that way 8/100ths lb per cubic foot using convection, the water in the engine is being heated by burning gasoline several thousand times per minute using direct conduction.


The other thing is the rate of heat rejection. The longer the coolant stays in the radiator the less efficient the radiator is. After the water gets close to ambient, the amount of difference in temp (Delta T) is minuscule. If the coolant is cold halfway across the radiator, you just made your radiator 1/2 it's size. When the temps are close together, very little transfer happens.


If you want to reject the most heat energy faster is better. Think of it like this, would you rather make a big fat $10 bill per hour or a lowly little penny every second?





The other reason slower isn't automatically better is if you slow the coolant flow down to a crawl, the front cylinders are ice cold while the heads on the front cylinders are hot as hell. Not to mention all the localized boiling that'll be going on above the combustion chambers.

 

[Nick Micale]

There is enough bullshit in this old thread to fill a box car!

It was 120 degrees here today, and it would be insane to drive a GN with a t'stat, especially if the AC was operating when driving.

A stock GN with a t'stat would have an operating coolant temp of 230-240 degrees, more if running with antifreeze which does not transfer heat as well as plain water?

We do not have damaging low temps here in the winter, so we do not ever run antifreeze or t'stats, but we do run RMI-25 to protect all the cooling system components.

We have proven many times that a GN, stock or modified, will always run cooler without a t'stat.

At the drag strip, a GN w/o a t'stat will cool down much quicker.