Running without a thermostat ok?

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RustyRatRod said:
No. It's not ok.
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Yes. It is ok. But you need a restrictor ring. Same thing your thermostat provides when it's open. If you run a electric water pump you are not supposed to run a thermostat.

To the OP, keep in mind you will always run hotter than whatever T-stat you put in because it doesn't open until it hits that number. This doesn't mean it will run cooler without one or with a colder stat though. That will depend on the rest of your cooling systems capability.
 
roccodart440 said:
Yes. It is ok. But you need a restrictor ring. Same thing your thermostat provides when it's open. If you run a electric water pump you are not supposed to run a thermostat.

To the OP, keep in mind you will always run hotter than whatever T-stat you put in because it doesn't open until it hits that number. This doesn't mean it will run cooler without one or with a colder stat though. That will depend on the rest of your cooling systems capability.
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I think some of yall too some stupid pills. Did the OP say anything about an electric water pump? No. He said something about "crusing down shady roads" so he;s clearly talking about a STREET CAR where you do NOT run an ELCETRIC WATER PUMP, but DO RUN a THERMOSTAT. Now, take the electric water pump race3 car talk somewhere else, cause we ain't talkin about that here. Thank you for your cooperation.
 
People do run electric water pumps on the street and CSR in particular designs theirs for that purpose. I ran one for over 10 years. It's still in the car. Still works fine.

The only difference between the electric pump and the mechanical is the speed it runs will never change. The mechanical pump RPM is dependent on engine RPM. So your whole electric vs. mechanical argument is invalid.
 

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roccodart440 said:
People do run electric water pumps on the street and CSR in particular designs theirs for that purpose. I ran one for over 10 years. It's still in the car. Still works fine.

The only difference between the electric pump and the mechanical is the speed it runs will never change. The mechanical pump RPM is dependent on engine RPM. So your whole electric vs. mechanical argument is invalid.
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No it is not. Please leave this nonsense out of the discussion. Plus, the answer has already been established. Engines should NOT be run withOUT thermostats. That is all
 
sargentrs said:
Thanks for all the input guys. The thermostat stays then. Good, I didn't feel like changing it anyway. This being my first slant, I'm not familiar with what is considered "normal" as far as water temp is concerned. So 210* is not unusual or too hot?
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Nah, 210 is not extreme. 185 is probably the right T-stat to use.

Prestone. Prestone, who needs Prestone?
I don't think anyone has mentioned coolant. Coolant raises the boiling temp right? So you should use it for a little more safety factor. It also has anti-corrosion properties.
You can also add water wetter.
 
67Dart273 said:
I keep trynnna tell you this. It ain't true. If an engine overheats without a stat it is NOT because "it goes through the radiator" too quick. However, you are right in one respect.......a stat, a good one, should be in place.
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I have found it to be true in a 440 powered Demon. I blocked the bypass in the water pump housing, had a fan shroud, good fan, cut vent holes in the fender wells, tried a 160 and no t-stat while running a 4 core Mopar radiator. The car would get hot in the drive thru etc. After I installed a 195 degree t-stat I had no more issues. Water passing through the radiator too quickly does not have time to "radiate" / dissipate the heat.

Another solution would have been an electric fan but at that time they were not as affordable or reliable. After installing the 195 it never got over 180 on the gauge. In a smaller engine the thermostat will probably take longer to cycle as it takes longer to heat the water in the block. Letting the water pause while in the radiator makes a big difference in how much heat is transferred.
 
You're not seeing over 180 degrees and you're running a 195 stat. Now that is really something.
 
roccodart440 said:
You're not seeing over 180 degrees and you're running a 195 stat. Now that is really something.
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I was amazed indeed. I learned something for sure. When the t-stat opened the water surged through and it had cooled enough in the radiator the sender didn't have time to respond either way to give more than an average reading.
 
So now your t-stat is closed all the time according to your gauge.
 
mguner said:
I was amazed indeed. I learned something for sure. When the t-stat opened the water surged through and it had cooled enough in the radiator the sender didn't have time to respond either way to give more than an average reading.
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I knew all those equations they forced on us were useless. I don't think I have ever seen a thermostat just pop open.
 
mguner said:
After installing the 195 it never got over 180 on the gauge. In a smaller engine the thermostat will probably take longer to cycle as it takes longer to heat the water in the block. Letting the water pause while in the radiator makes a big difference in how much heat is transferred.
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If any of this is true, the laws of thermodynamics do not apply to your car.

I suggest you start filing patents and looking for grant money to do research, because every physics and thermodynamics text written in the last couple hundred years must be wrong.

Meanwhile, you can remove your radiator entirely and just connect your top and bottom hoses. If the temp is never above 180, and the thermostat is a 195, it never opens. Where is the sending unit for the temp gauge? Think about it for a second...

Finally-
The problem with thinking water needs to spend more time in the radiator is that it must spend more time in the engine for that to happen. It's a closed system. If the radiator can dissipate more heat than the engine can put in (which it can if your cooling system works!!!), you need to circulate MORE water, not less. Which is why high volume water pumps work better than standard ones for modified engines which make more heat. You want more water to move through the radiator, not stay there longer.

Yes, you need a thermostat. Your car will get just as hot without one, and it will also take longer to warm up, which will trash your engine.
 
I love these know it all engineer types and wanna be engineer types. Heat transfer is not instantaneous although non ferrous metals do perform better than iron. Now figure the difference in surface area and conductivity between the inside if the block and the inside of the tubes in a 4 core brass or aluminum radiator. Apply the wrapping function of Pi to the diameter of the dohicky. The thermostat does not have to open that fast to generate a rapid flow. The same thermodynamics that make the thermostat somewhat sluggish are also why the 1970s era temp sending unit does not respond as fast as a thermistor. The location of the sending unit in relation to the sender will also give a somewhat false reading. So you seem to be saying that a skillet should instantly fry an egg as soon as you put it on the stove.. or does it take a while to "transfer" the friggin heat?

The problem being solved was for a vehicle not in motion. If the same amount of air went through the radiator at a stop as it did in motion a much smaller radiator would be perfect and all the rules of a closed system and constants would apply.
 
mguner said:
I love these know it all engineer types and wanna be engineer types. Heat transfer is not instantaneous although non ferrous metals do perform better than iron. Now figure the difference in surface area and conductivity between the inside if the block and the inside of the tubes in a 4 core brass or aluminum radiator. Apply the wrapping function of Pi to the diameter of the dohicky. The thermostat does not have to open that fast to generate a rapid flow. The same thermodynamics that make the thermostat somewhat sluggish are also why the 1970s era temp sending unit does not respond as fast as a thermistor. The location of the sending unit in relation to the sender will also give a somewhat false reading. So you seem to be saying that a skillet should instantly fry an egg as soon as you put it on the stove.. or does it take a while to "transfer" the friggin heat?
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If you have a 195 thermostat, and your car never gets above 180 on your temperature gauge, your thermostat NEVER opens. Ever. For any reason. The temperature sending unit and the thermostat both see the same exact temperature water if the thermostat is closed and the rate of rise from the engine alone is more than slow enough to be captured by the sending unit.

So, either your thermostat is inaccurate, or your temperature gauge is.

Next. Thermal conductivity of metals (k), measured in W/(m K)

Cast iron- 55
Brass- 109
Copper- 400
Aluminum-205

So, worst case, the metals in the radiator transfer heat twice as fast as the engine does. Realistically, its better than that, because you're also talking about the surface area of the radiator, and the fact that it's a heat exchanger, which is ALSO exchanging heat with the moving air around it, not just into the metal of the radiator.

Now, if you think water travels through the radiator instantaneously, I can't help you. With the volume the water pumps on these cars put out, there will be plenty of time in the radiator to cool the water. And remember, its a CLOSED system. So, if you increase the time in the radiator, you increase the time in the engine. The two are directly related.

Realistically, you CAN'T pump the water through a regular radiator so fast that it doesn't cool with any kind of water pump that's going to fit in your engine compartment. Even if you did, think about it, you'd also be pumping the water through the engine so fast it couldn't take in any heat. Remember that the radiator is many times more efficient at transferring heat than the engine is.

So, tell me about the time you melted down an engine and the water in the cooling system was still cold. When you do that, you can talk to me about how water is circulating through the radiator too fast.
 
69_340_GTS said:
:argue:
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yeah, I get it, I'm :banghead:.

Not my fault people don't understand how their radiators work. Although I should probably know better by now than to get worked up about it. Not my car, not my problem.
 
Getting back to the original question by the OP....warning, this is a bit long, but I hope worth your while to read:

Yes flow rate does matter in heat transfer in the radiator. If flow rate did not matter at all, then we could have ZERO flow rate and still have heat transfer. We all know that is not the case.....The higher the flow rate, the higher the heat transfer rate. But it is not a strong relationship; doubling the flow rate does not double heat transfer rate. It increases it in ROUGHLY the range of 25-50%; depends on if the internal rad flow is laminar or turbulent.

So if you take out the thermostat, then will flow rate increase? Depends. The main restrictions are the t'stat, the rad, and the flow restrictions in the block-to-head coolant flow path. The rad is the least restictive so it is down to the t'stat or the block-to-head flow openings. Taking the t'stat out (I will guess) does not really change the flow rate a whole lot, because the block to head flow restrictions are still there.

But, there is one more factor to consider: that is local pressures in the coolant. There is obviously a pressure difference around the cooling system: it starts highest at the pump outlet and gets lower and lower as after passing through each restriction and is lowest at the pump inlet.

If the largest restriction is at the block-to-head restrictions, then there is a significantly lower coolant pressure after that restriction....i.e., inside the heads. This is the place where you do not want a low coolant pressure because most of the heat is coming into the cooling system in the heads, and it will have the highest likelihood of boiling at localized hot spots. Having the t'stat in place and partly closed moves the largest restriction to the t'stat, and the pressure in the head will be higher and less likely to have localized boiling points in the head's water jacket.

So, for that reason, keep the t'stat in place and operational. If you have ever read about people taking out the t'stat and the car getting hotter, then lower coolant pressure in the head may well be the culprit.

From a C&R Racing article that touches on this [italics are mine]:
"Pressure throughout the system will vary determineddue to different restrictions at each location in the system. The system will be at less pressure before the water pump than after it. However, system pressure willbe at higher pressure before the core and lower afterwards. These pressure differentials happen throughout the engine due to the changes in water passage cross section. Bernoulli’s equation explains this phenomenon well. The cylinder head is the location that needs the highest pressures to reduce boiling risks. "
 
Tell me about the time you ran your hand through a flame and it melted off! Geez some people can't handle logic over their own BS! The pressure in the heads-YES thank you nm9! 72 you forgot the lecture about the coolant mixture vs straight water as well.... more variables. I know what I had and I know what it did. You want to conduct your own experiment go for it.
 
The whole wifes tale about water circulating to fast to cool, is just that, a wifes tale. Its not true at all. The thing that makes water restrictors work, is the fact that it allows the water pump to build more WATER PRESSURE in the system......that's the key.....
 
RustyRatRod said:
Well, no matter how hard you try to tell some of THEM that, THEY just will not listen.
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Agreed, a little simple reading would go along way to help people understand, but for lots of people, reading some random, unproven claims on a site, can replace science and fact.........I think I need to take a break like you!
 
The great thing about "lively" discussions is that I LEARN SOMETHING NEW when they happen.

So....thank you all for the information and thank you Sargentrs!!!
 
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