When will replacing a thermostat improve cooling?

[ForceFed70]

I've seen so much missinformation about thermostats and cooling systems in the last few days, I decided to make a post just for this.

So when will changing a thermostat improve cooling system performance?

The short answer is: "On a normal engine with all parts in working order...never"

BUT, changing a thermostat can help cure some problems.

1) If your engine is boiling over because of "hot spots" in the engine, switching to a colder thermostat may help. But really, these hot spots need to be fixed. This doesn't improve total cooling efficiency, it just stops the coolant from boiling inside of the engine.

2) If your thermostat is defective, or starting to fowl up (restricting flow) then REPLACING the thermostat will resolve the problem.

Contrary to popular belief, removing the thermostat completely or putting in a low temp thermostat will NOT cause your engine to overheat because "the coolant doesn't spend enough time in the radiator to cool down" due to the increased speed of circulation. By the same logic "the coolent also doesn't spend as much time in the engine to heat up".

There are only 3 ways to increase the performance of a cooling system:

1) Switch to a radiator that has a better rate of heat exchange. (Ie: larger rad, switch to aluminum, more cores, etc)
2) Increase the amount of air flow through the radiator (Ie: fan shround, better fan, grill mods, etc)
3) Lower the temperature of the air going through the radiator and surrounding the engine.

The thermostat is there ONLY to control the normal operating temperature of the engine. If the engine is running too hot changing the thermostat will NOT help unless the thermostat is broken/defective.

 

[rbohm]

Contrary to popular belief, removing the thermostat completely or putting in a low temp thermostat will NOT cause your engine to overheat because "the coolant doesn't spend enough time in the radiator to cool down" due to the increased speed of circulation. By the same logic "the coolent also doesn't spend as much time in the engine to heat up".

your logic is flawed in this case. you indicated in another thread that one should ask an hvac tech about this. as i stated in that thread, you are dealing with two different systems, and two completely different coolants(in the case of a/c, refrigerant). when you remove a tstat from an engine, it does increase flow through the rad, and the coolant cannot transfer heat from itself to the rad to be rejected to the air efficiently. your thinking is also flawed when you state that the coolant is also flowing through the engine faster and doesnt have time to heat up. in regards to that, engine coolant is designed to absorb heat efficiently, to remove it from engine parts, and then to transfer that heat to the rad. however, when you design something to absorb heat efficiently it does not transfer that heat easily. that is why you must slow the coolant flow through the rad with some sort of restriction, either a thermostat or the old fashioned restrictor plate as we used in our race engines, a brass plate with a hole in it. even the racers know you need to slow coolant through the rad.

refrigerant on the other hand is designed to reject heat easily under pressure, thus you just air that is cooler than the refrigerant is, for the refrigerant to give up its heat and become a liquid again.

 

[ForceFed70]

your logic is flawed in this case. you indicated in another thread that one should ask an hvac tech about this. as i stated in that thread, you are dealing with two different systems, and two completely different coolants(in the case of a/c, refrigerant). when you remove a tstat from an engine, it does increase flow through the rad, and the coolant cannot transfer heat from itself to the rad to be rejected to the air efficiently. your thinking is also flawed when you state that the coolant is also flowing through the engine faster and doesnt have time to heat up. in regards to that, engine coolant is designed to absorb heat efficiently, to remove it from engine parts, and then to transfer that heat to the rad. however, when you design something to absorb heat efficiently it does not transfer that heat easily. that is why you must slow the coolant flow through the rad with some sort of restriction, either a thermostat or the old fashioned restrictor plate as we used in our race engines, a brass plate with a hole in it. even the racers know you need to slow coolant through the rad.

refrigerant on the other hand is designed to reject heat easily under pressure, thus you just air that is cooler than the refrigerant is, for the refrigerant to give up its heat and become a liquid again.

Ugh.. your making me think.

1st.. HVAC IS TOTALLY relevant. It's just a more complicated system with regards to AC and condensive/evaporative systems. When HVAC technicians are trained, they start off with simple cooling systems like found in cars. I said "Ask a HVAC technician if you won't believe me", I didn't say the systems are the same.

As for your talk about coolant.. your looseing me on that one. The ability for coolant to "absorbe heat" vs "give it away" is always the same. I think you are getting the ideas between thermal capacity and thermal resistance mixed up here.

Either way... take a step back and look at this from a different angle:

Are we in agreement that a cooling system must remove the same amount of heat as the engine produces? (heat loss from just engine to air contact put asside). Let's say the engine is starting to overheat and the 195* thermostat is stuck open...pumping 195* coolant into the radiator. After a minute or 2 the temp of the coolant in the radiator is going to be very close to 195*. Now tell me this... if the temp of the coolant is 195*, will the radiator remove less heat because of the speed in which the coolant is moving through it? The coolant inside is a constant 195* so why would less heat be removed? In fact, MORE heat energy is removed because there is a greater difference between air temp and coolant temp.

How about you try an experiment at home? Take 2 exact same glasses of water. Now, put 1 in the oven for 10 minutes, then in the freezer for 10 min. Take the other and put it in the oven for 5 min, then the freezer for 5 min, then the oven for another 5 min, and finally the freezer for another 5 min. Measure the temperature of the water after you are done. You'll find that the water is the same temp in both cases.

 

[D.Hearne]

70 nitrous eater------- you're missing the fact that a T-Stat IS simply a restrictor, when functioning properly. Actually more like a regulator who's function is to keep the coolant flow under control, it slows the coolant down when the engine gets too cold, speeds it up when it's too warm, but only to the point where it's simply being in the coolant's path causes a restriction. Remove it entirely and it will cause an engine to run hot once it gets to a certain point,but this will only happen if the rest of the system isn't perfectly matched to the needs of the engine. I've seen it happen TOO many times over the years for this not to be true. In the case of my V8 Ranger, switching from a 180 degree to a 160 degree T-stat lowered the normal temp about 10-15 degrees. To try your theory in what would happen if I removed it altogether? Not a chance. I don't have time for trying it and I'm not going to risk a $4000 motor, to see what I already know what would happen.

 

[Route666]

Yeh with the thermostat slowing flow down, the coolant has more time in the engine to absorb heat, and spends more time in the radiator at a higher temp, thus a higher delta T, so not only cools the coolant quicker (initially), but for longer, so with the thermostat restriction in place, the cooling system as a whole can remove more heat from the engine than it could if it were running around real fast, at a mediocre temperature.

The cooling system doesn't remove temperature from the engine, it removes energy, the result of which is the engine holds a consistent temperature - the ideal situation for a machine. Temperature and energy (heat) are closely related, but are not the same thing, and while it may seem ideal to keep the cooling system at a constant temp, by running it through the engine faster, it actually detracts from its ability to transmit energy (in the form of heat) from the engine to the radiator.

Thus it is quite possible for an engine to run hotter without a thermostat than when it had one. It also takes longer to get it to the optimum, best running, least wearing temperature.

 

[ForceFed70]

70 nitrous eater------- you're missing the fact that a T-Stat IS simply a restrictor, when functioning properly. Actually more like a regulator who's function is to keep the coolant flow under control, it slows the coolant down when the engine gets too cold, speeds it up when it's too warm, but only to the point where it's simply being in the coolant's path causes a restriction. Remove it entirely and it will cause an engine to run hot once it gets to a certain point,but this will only happen if the rest of the system isn't perfectly matched to the needs of the engine. I've seen it happen TOO many times over the years for this not to be true. In the case of my V8 Ranger, switching from a 180 degree to a 160 degree T-stat lowered the normal temp about 10-15 degrees. To try your theory in what would happen if I removed it altogether? Not a chance. I don't have time for trying it and I'm not going to risk a $4000 motor, to see what I already know what would happen.

A realize what the thermostat does. It's controls the operating temperature of the engine. And in reality, it's more of an open/close system than a variable restrictor, but that doesn't make a difference anyway.

The thermostat is only there to CONTROL the temperature of the engine (in a healthy system). Without it's control, the engine operates at whatever temperature your cooling system is at. On a hot day, it may be close to normal operating temp... in the middle of the winter it will be much colder.

And you obviously do not already know what would happen if you removed you thermostat. What happens is that the engine would take forever to warm up, and even then it wouldn't reach normal operating temp unless it's a very hot day out. Take it from someone who HAS had a car with the thermostat removed. Who has seen it 1st hand.

 

[ForceFed70]

Yeh with the thermostat slowing flow down, the coolant has more time in the engine to absorb heat, and spends more time in the radiator at a higher temp, thus a higher delta T, so not only cools the coolant quicker (initially), but for longer, so with the thermostat restriction in place, the cooling system as a whole can remove more heat from the engine than it could if it were running around real fast, at a mediocre temperature.

The cooling system doesn't remove temperature from the engine, it removes energy, the result of which is the engine holds a consistent temperature - the ideal situation for a machine. Temperature and energy (heat) are closely related, but are not the same thing, and while it may seem ideal to keep the cooling system at a constant temp, by running it through the engine faster, it actually detracts from its ability to transmit energy (in the form of heat) from the engine to the radiator.

Thus it is quite possible for an engine to run hotter without a thermostat than when it had one. It also takes longer to get it to the optimum, best running, least wearing temperature.

Temperature/heat IS energy, the only differences come into play when you look at the thermal capacity of the medium. For example 1gram of water at 100* has more heat energy than 1 gram of oil at 100*. But since our medium doesn't change, this is irrelivant.

I'm not saying that moving the coolant faster through the system is better. BUT I am saying that it isn't worse.

Man.. I'm having a hard time making you guys understand this.
The amount of time the coolant spends inside of the engine or inside of the radiator is not a consideration. It's the TEMPERATURE of the coolant that matters. True, having it sit in the rad longer will make the coolant drop in temp more...but having it sit in the engine longer will make it increase in temp more. You cannot have 1 without the other.

I don't know how else to explain it than to look at the total system.
Heat produced in the engine must be removed in the radiator. It's that simple. And I think everyone agrees on this.

How much heat is removed by the radiator depends on airflow, radiator efficiency, and the temperature of the ambient air. It has nothing to do with the thermostat.

This might help... say we have a situation where it's a very hot day, and the cooling system is just barely adequate to stop the car from boiling over. The temp inside the engine/cooling system is a constant 200* and since you have a 180* thermostat in there, it's open non-stop. Answer the following questions for me please:
1) Since the thermostat is open non-stop, Is this not the same thing as having no thermostat in there at all?
2) Would having the thermostat close help cooling?
3) At this point, what is the difference between having a thermostat that is staying open vs no thermostat at all?
4) How would changing a thermostat effect the radiators ability to remove heat from the coolant?

 

[68torino]

One point being missed in the argument is the difference between older cars/cooling systems and newer cars/cooling systems. I have been running all sorts of vehicles for over 35 yrs, to include diesels, gas engined cars, trucks and motorcycles. On older 50s, 60s and 70s vehicles if you remove the thermostat they will typically overheat. I've had this happen to me and other people I have known. Generally this due to to the fact that cooling systems were inefficent. On most newer vehicles later 80s and up this MIGHT NOT be the case. In some instances it could run cooler IF it has a overly efficent system.

If a unit running the correct thermostat is overheating even a small consistant amount something else is wrong. I will not recommend trying a bandaide cure of switching to a cooler thermostat. If the are hotspots then a simple vacuum system purge would help get rid of trapped air bubbles. I would check my radiator and AC coils to see if they were plugged or to many fins bent.

Quote by 70_Nitrous_Eater:

This might help... say we have a situation where it's a very hot day, and the cooling system is just barely adequate to stop the car from boiling over. The temp inside the engine/cooling system is a constant 200* and since you have a 180* thermostat in there, it's open non-stop. Answer the following questions for me please:
1) Since the thermostat is open non-stop, Is this not the same thing as having no thermostat in there at all?
2) Would having the thermostat close help cooling?
3) At this point, what is the difference between having a thermostat that is staying open vs no thermostat at all?
4) How would changing a thermostat effect the radiators ability to remove heat from the coolant?

Even though a 180* thermostat is open all the time it still provides some restriction to coolant flow as opposed to no thermostat, look at the opening size difference. Getting rid of the thermo energy of the coolant is related to time and air flow speed over the tubes of the radiator and effiency of the SYSTEM. If unrestricted coolant is allowed to run thru a system, designed to work in conjunction WITH a thermostat, does not have that thermostat it will not slow down enough to allow it to cool efficently. By the same token if you have an overly efficent cooling system and you run it with no thermostat it will not be able to get up to operating temps. Ask anyone who in the 60s and 70s that ran a big block radiator against a small block and tried to get heat in the winter.

I have had a '66 F100 300six that Ford had one radiator for all the motors from sixes to 390s. Even with a 195* thermo I could not get heat in the winter unless I covered the radiator with cardboard. I've had a '74 E300 with a 302 and 190* thermostat that would not cool at idle because of a weak water pump which would not flow the coolant at a rate sufficent to cool it. Coolant is designed to absorb thermo energy and transfer it. But if you mess with the system you risk toasting your engine. By overheating it or running too cold and washing the cylinders of oil. But it is your motor you can do what you want. Me I recommend running at least a 180*-185* thermostat and going to a 190*-195* if it runs to cool. What's to cool? It should run consistantly in the middle range of a factory gauge, you should see a flucuation of the needle, however small, indicating the opening and closing of the thermostat.

Besides if not having a thermostat improved cooling, don't you think the manufactures would eliminate it to save them a few hundred thousand dollars? If it costs them say 25 cents per stat X several million vehicles per year. I know if I was a bean counter I'd go for it.

 

[ForceFed70]

Even though a 180* thermostat is open all the time it still provides some restriction to coolant flow as opposed to no thermostat, look at the opening size difference. Getting rid of the thermo energy of the coolant is related to time and air flow speed over the tubes of the radiator and effiency of the SYSTEM. If unrestricted coolant is allowed to run thru a system, designed to work in conjunction WITH a thermostat, does not have that thermostat it will not slow down enough to allow it to cool efficently. By the same token if you have an overly efficent cooling system and you run it with no thermostat it will not be able to get up to operating temps. Ask anyone who in the 60s and 70s that ran a big block radiator against a small block and tried to get heat in the winter.

I have had a '66 F100 300six that Ford had one radiator for all the motors from sixes to 390s. Even with a 195* thermo I could not get heat in the winter unless I covered the radiator with cardboard. I've had a '74 E300 with a 302 and 190* thermostat that would not cool at idle because of a weak water pump which would not flow the coolant at a rate sufficent to cool it. Coolant is designed to absorb thermo energy and transfer it. But if you mess with the system you risk toasting your engine. By overheating it or running too cold and washing the cylinders of oil. But it is your motor you can do what you want. Me I recommend running at least a 180*-185* thermostat and going to a 190*-195* if it runs to cool. What's to cool? It should run consistantly in the middle range of a factory gauge, you should see a flucuation of the needle, however small, indicating the opening and closing of the thermostat.

Besides if not having a thermostat improved cooling, don't you think the manufactures would eliminate it to save them a few hundred thousand dollars? If it costs them say 25 cents per stat X several million vehicles per year. I know if I was a bean counter I'd go for it.

The thermostat serves a very good purpose. In controls the operating temperature of the engine. Engines are made to run at a certain temp. Eliminating the thermostat would cause the engine to often run cooler than designed (especially during the winter) and thus increase wear, and reduce efficiency. THAT is why it's there...

Again.. how does "coolant restriction" improve the radiator's efficiency? Explain to me how a radiator removes more heat when the coolant moving through it is going slower. In simple terms: Heat created by the engine is removed by the radiator. Don't talk about the temp of the coolant, only tell me how it removes more heat from the whole system. Again: why do you think the radiator removes more heat when the coolant cycles through it once a minute vs twice a minute?

And I'm all for running the proper thermostat. That's the whole point to this thread. My point is that changing the thermostat does not improve cooling. It only effects the temperature in which the engine runs at.

 

[jbuening]

Ugh, this reminds me of my thermodynamics class. I'll leave this thread to you Mechanical Engineers (structural engineer here )

 

[68torino]

If you have no coolant restriction and the coolant is moving through the radiator tubes to fast to extract enough thermo energy your motor will overheat. If you have no restriction and the coolant goes thru the tubes of an overly efficent radiator/moving air system to fast your motor will not come up to operating temp. If you have a restriction that operates in the zone of effiency of the rdiator/moving air system your motor will stay in it's optimum operating temp. Change any of the above, no restriction, to much restriction, to efficent radiator/moving air cooling system, not efficent enough radiator/air cooling sytem and this changes where your motor temps run.

Your statement:
"Contrary to popular belief, removing the thermostat completely or putting in a low temp thermostat will NOT cause your engine to overheat because "the coolant doesn't spend enough time in the radiator to cool down" due to the increased speed of circulation. By the same logic "the coolent also doesn't spend as much time in the engine to heat up"."

Failed to take into consideration older systems that may be inefficent due to design or simply partially plugged up. I was trying to make the distinction between inefficent systems which will overheat(had it happen) and efficent or overly efficent systems that MIGHT go into over cooling which is detrimental to a motor. Had that too.

Bottom line for me is when I give advice about thermostats I recommend running a 190*-195* thermostat. It gets dang cold here in SD and it gets dang hot also. I have never had a problem running a 190*-195* stat. My father-in-law told me many moons ago to stick in that range and since he ran the No. 1 Diesel repair place in Sioux Falls years ago I took his advice and have never gotten burnt.

If you want to tell people it is alright to not run a thermostat, go for it. But if they wreck their motor, your head not mine.

 

[ForceFed70]

If you have no coolant restriction and the coolant is moving through the radiator tubes to fast to extract enough thermo energy your motor will overheat. If you have no restriction and the coolant goes thru the tubes of an overly efficent radiator/moving air system to fast your motor will not come up to operating temp. If you have a restriction that operates in the zone of effiency of the rdiator/moving air system your motor will stay in it's optimum operating temp. Change any of the above, no restriction, to much restriction, to efficent radiator/moving air cooling system, not efficent enough radiator/air cooling sytem and this changes where your motor temps run.

Your statement:
"Contrary to popular belief, removing the thermostat completely or putting in a low temp thermostat will NOT cause your engine to overheat because "the coolant doesn't spend enough time in the radiator to cool down" due to the increased speed of circulation. By the same logic "the coolent also doesn't spend as much time in the engine to heat up"."

You keep saying the same thing. And I keep asking you the same questions.
This is a closed loop system. Heat created in the engine is removed by the radiator. Explain how the speed in which the coolant moves through the radiator would change the total amount of heat removed by the radiator! Or do you believe that it causes the engine to produce more heat?

How about this. What's the difference between the coolant spending 1 minute in the engine, then 1 minute in the radiator and repeating (2 minutes in both). Vs the coolant spending 2 minutes in the engine then 2 minutes in the radiator? Total time in the engine and radiator is the EXACT same. Total cooling is the EXACT same. You need to look at the big picture here...

Failed to take into consideration older systems that may be inefficent due to design or simply partially plugged up. I was trying to make the distinction between inefficent systems which will overheat(had it happen) and efficent or overly efficent systems that MIGHT go into over cooling which is detrimental to a motor. Had that too.

I failed to take this into consideration because it's irrelevant to this discussion. The system will still be bunged up and not as efficient no matter what thermostat is being used. And I agree, removing the thermostat will cause the engine to run too cold at times. Which isn't good for the motor..

Bottom line for me is when I give advice about thermostats I recommend running a 190*-195* thermostat. It gets dang cold here in SD and it gets dang hot also. I have never had a problem running a 190*-195* stat. My father-in-law told me many moons ago to stick in that range and since he ran the No. 1 Diesel repair place in Sioux Falls years ago I took his advice and have never gotten burnt.

If you want to tell people it is alright to not run a thermostat, go for it. But if they wreck their motor, your head not mine.

This is the 2nd time I've said this. I'm all for running the proper thermostat. That's the whole point to this thread. My point is that changing the thermostat does not improve cooling. It only effects the temperature in which the engine runs at. Re-read the initial post. Where am I reccomending people remove their thermostat? I said it will not cause the engine to overheat. I'm saying the EXACT OPPOSITE..that changing or removing the thermostat will not help in most cases. I'm starting to wonder if you really understand my point here.

 

[D.Hearne]

70 nitrous eater......... it takes a certain amount of time for the radiator to remove the heat, it doesn't happen instantly. It also takes time for the coolant to absorb heat. Also you have to take into consideration that the engine is constantly running in varying conditions, it's not always producing the same amount of heat. In your scenario it is. Your theory is more like a stationary engine, powering something like an irrigation pump......... a constant speed application. And you keep leaving out the fact that the T-stat in itself is a restriction to the coolant flow, be it open or closed. If you want to run your motor without a T-stat, be my guest, it's your motor. In mine, I'll keep it.

 

[jbuening]

Might i add that normally when someone removes their thermostat, they are already having overheating problems and think that removing the thermostat will lower their temps and stop the overheating. This tends to be the case when people refer to an engine overheating without a thermostat. Removing the thermostat doesn't cause the motor to overheat, a weak water pump or plugged/too small radiator will!!! This is in an ideal case though. It all depends on how nice you are to the motor and the outside temps you are driving in.

 

[68torino]

This is the 2nd time I've said this. I'm all for running the proper thermostat. That's the whole point to this thread. My point is that changing the thermostat does not improve cooling. It only effects the temperature in which the engine runs at. Re-read the initial post. Where am I reccomending people remove their thermostat? I'm saying the EXACT OPPOSITE! I'm starting to wonder if you really understand my point here.

I did say IF.

Changing the speed/volume can affect how well the radiator removes heat as I said. Go thru to slow and too much cooling. Go thru too fast and not enough cooling. When I say fast or slow I'm talking about volume, too little volume flow will cool faster. Too much volume flow will not shed enough heat. Given the same system and disregarding any restrictions in the system that would cause hotspots and actual overheating.

Again your statement: "Contrary to popular belief, removing the thermostat completely or putting in a low temp thermostat will NOT cause your engine to overheat because "the coolant doesn't spend enough time in the radiator to cool down" due to the increased speed of circulation." Says will not.....Which by it's nature encompasses all motors regardless of age and condition/thermo rating of the cooling system. A more accurate statement might have been "that in modern engines typically if you remove the thermostat this may have the effect of overcooling your engine due to the fact that most modern engines have a far more effiecnt cooling systems" " on older vehicles removing the thermostat typically has resulted in an overheating situation."

 

[ForceFed70]

70 nitrous eater......... it takes a certain amount of time for the radiator to remove the heat, it doesn't happen instantly. It also takes time for the coolant to absorb heat. Also you have to take into consideration that the engine is constantly running in varying conditions, it's not always producing the same amount of heat. In your scenario it is. Your theory is more like a stationary engine, powering something like an irrigation pump......... a constant speed application. And you keep leaving out the fact that the T-stat in itself is a restriction to the coolant flow, be it open or closed. If you want to run your motor without a T-stat, be my guest, it's your motor. In mine, I'll keep it.

UGH!!!! Where am I saying someone should remove their thermostat? I'M SAYING THE EXACT OPPOSITE!!!!! Sorry, just getting a little frustrated. I've only said that removeing the thermostat will not cause the engine to overheat.

True.. engine conditions are always changing. Which if anything would be a good argument for more coolant flow. This would help to smooth out spikes and drops in temp.

We need to get away from this whole "time in the engine and time in the radiator" thing. It doesn't matter... what matters in the temperature.

Again.. what's the difference between the coolant spending 1 minute in the engine then 1 minute in the radiator then repeating (2 minutes in both) vs. spending 2 minutes in the engine then 2 minutes in the radiator? The only difference would be the total change in temperature of the coolant. But this does NOT change the total amount of heat absobed from the engine and removed from the radiator.

 

[ForceFed70]

Changing the speed/volume can affect how well the radiator removes heat as I said. Go thru to slow and too much cooling. Go thru too fast and not enough cooling. When I say fast or slow I'm talking about volume, too little volume flow will cool faster. Too much volume flow will not shed enough heat. Given the same system and disregarding any restrictions in the system that would cause hotspots and actual overheating.

This is going to drive me nuts!

Again. we need to step back and take a look at the big picture. If the temperature of the coolant is 200*, the radiator will remove the same amount of heat no matter what the speed in which the coolant flowing through it is. This is the key fact! You cannot dispute this. This is heat comming from the engine.

Look at total heat... not just heat through a portion of a cooling cycle.

A more accurate statement might have been "that in modern engines typically if you remove the thermostat this may have the effect of overcooling your engine due to the fact that most modern engines have a far more effiecnt cooling systems" " on older vehicles removing the thermostat typically has resulted in an overheating situation."

But it's not the case. Removing the thermostat does not cause overheating problems in a normal classic engine. Look at the 5.0 the cooling system is the same general design from the late 60's all the way up to 95. I've owned a classic that had the thermostat removed and all it did was cause the engine to run cold unless it was a very hot day, then it would reach near normal temperatures depending on the conditions.

 

[D.Hearne]

UGH!!!! Where am I telling people to remove their thermostat! I'M SAYING THE EXACT OPPOSITE!!!!! Sorry, just getting a little frustrated. I've only said that removeing the thermostat will not cause the engine to overheat.

True.. engine conditions are always changing. Which if anything would be a good argument for more coolant flow. This would help to smooth out spikes and drops in temp.

We need to get away from this whole "time in the engine and time in the radiator" thing. It doesn't matter... what matters in the temperature.

Again.. what's the difference between the coolant spending 1 minute in the engine then 1 minute in the radiator then repeating (2 minutes in both) vs. spending 2 minutes in the engine then 2 minutes in the radiator? The only difference would be the total change in temperature of the coolant. But this does NOT change the total amount of heat absobed from the engine and removed from the radiator.

Oh, but it does......... It takes longer to remove the heat from the coolant than it does to put it there. The engine is always capable of producing heat faster than the radiator can remove it. The radiator size is a constant, the engine's ability to produce heat is not. If the coolant is hotter, then it's obviously removed more heat from the engine.

 

[D.Hearne]

Besides. you're out numbered here too.

 

[ForceFed70]

Let's draw an analogy....

There are 2 cars on a oval track, driving circles all day long. The oval is facing east - west. 1 car is driving 40mph, the other car is driving 80mph. Does any 1 car spend more total time on the east side of the oval?