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Why use a t-stat?

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Old 07-29-2008, 08:28 AM
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My engineering degree was earned a very long time ago, and I haven't used it since so...
My bottom line is that I know what I have personally experienced... and that is that STREET cars I have owned have performed better with the proper T-stat. The proper T-stat in a properly working cooling system keeps the coolant in the correct operating range. Yes, in the winter you need the T-stat to function and function only when it should. I had a BMW that would prove you wrong if you try to tell me otherwise. T-stat stuck open (effectively NO T-stat) and you couldn't get heat/defrost no matter how long you drove. In winter conditions the coolant simply wouldn't get warm enough.

Remember guys, I am talking about street cars. Other posters may not necessarily be and I'm not speaking for them.
Old 08-01-2008, 11:37 PM
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If you really believe that your car will overheat w/out a stat because the coolant wont have time to pick up the heat, then you also believe that you wont get frostbite on top of Mt Washington in mere seconds by 150+mph winds because the fast moving air doesn't have have time freeze your exposed flesh.
Old 08-07-2008, 12:32 AM
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basically if you ask 100 people you will get 100 different answers, but in my personal expierience, ive never had a car overheat because of the lack of a thermostat...ive discussed this before with my tech school teacher, and he insists that you need a thermostat to bring the engine to correct operating temperature, and without it, you wont hit the right temp...either higher or lower...but its up to you really
Old 08-07-2008, 12:42 AM
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thermostats are for heating the engine up, not keeping it cool.

water is one of the best fluid conductors... and the coolant and water wetter you should have mixed in with it are even better conductors of heat. they have plenty of time to collect heat, no matter how fast they are moving through.

and when they are forced through the radiator, they have plenty of time to shed it. period. no matter what speed the coolant is moving... it will spend the same amount of time in the block and radiator, as long as the circulation pattern doesn't change.

a thermo is important so your engine will heat up quicker, and that is all. that's why it changes heat up times for climate control.
Old 08-07-2008, 07:41 AM
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Originally Posted by AxisOfOil
thermostats are for heating the engine up, not keeping it cool.

water is one of the best fluid conductors... and the coolant and water wetter you should have mixed in with it are even better conductors of heat. they have plenty of time to collect heat, no matter how fast they are moving through.

and when they are forced through the radiator, they have plenty of time to shed it. period. no matter what speed the coolant is moving... it will spend the same amount of time in the block and radiator, as long as the circulation pattern doesn't change.

a thermo is important so your engine will heat up quicker, and that is all. that's why it changes heat up times for climate control.

Agree 100%, as I mentioned.
I've read several articles & they all say the old story that the water must go through the radiator slowly is a wives tale.
If anyone is so worried about time spent in radiator. The best way is get a cross flow & double the time spent in radiator.

.
Old 08-07-2008, 10:26 AM
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Actually you need speed in the radiator or a thin layer of coolant will stick to the surface and insulate the metal from the rest of the fluid.
This is one of the fundametals of heat exchangers technology.
Old 08-07-2008, 10:55 AM
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tici... another valuable point.
get a low temp thermo if you want your car to run cooler.
get a high temp thermo if you want your heater to work better.
Old 08-07-2008, 03:41 PM
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Originally Posted by tici
Actually you need speed in the radiator or a thin layer of coolant will stick to the surface and insulate the metal from the rest of the fluid.
This is one of the fundametals of heat exchangers technology.
Most heat exchangers now have "tubulators" little fins inside of the tubes that break up this boundry layer. 10-15 years ago your statement would have been more correct. The only real arguement to this that I have yet to see brought up is getting to the proper oil temerature. Yes, the coolant temp effects this quite a bit more than some realize. If your oil temps drop below 160 you WILL have oiling issues with the car. This is where a thermostat comes into play, getting the whole engine heated up, clearances in check and oil happy.

Last edited by Drew04GTO; 08-07-2008 at 03:50 PM.
Old 08-09-2008, 12:53 AM
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So i have looked at this thread for awhile, and today i did a little experiment. I took out my factory stock 02 pickup thermostat, the one thats part of the housing. Normally it runs about 189-195*. I looked it over really well and was just gonna go without as per the thread, but decided to try something to possibly benefit this thread. So i looked it over and the design just doesnt let much water through even under full open conditions. Also i wanted to keep my bypass valve in place. So, i decided to remove the rubber seal on the main body. Upon doing this the amount of flow was increased dramatically!. Also i noticed that the housing has a bunch of small holes for the rubber to embed in. I drilled every other hole out to about double its size and reassembled. Now the car heats to 140 or so rather quickly still, but climbs very slowly after. It stays in the 160s for quite some time, and runs about 172-174* in stop and go. I also turned off the fan and took it to 200*, and it cooled to 174 within a few minutes. I think if I drill every hole out it will stay in the mid 160s, but my single electric fan just isnt very big to exchange the air.
So, i think this may be a good way to keep both ends of the argument, just enough restriction to get temps up, but still ample flow to adequately cool the motor. I tood some pics of the finished product to illustrate.
Gary

Last edited by Grr; 06-07-2009 at 01:18 PM.
Old 08-09-2008, 11:15 AM
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I'm sure a thermostat is another one of those parts all the major automakers put on their vehicles that the backyard mechanic found just aren't needed. Much like an egr valve, air injection, abs...
Old 08-09-2008, 12:32 PM
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Originally Posted by AxisOfOil
thermostats are for heating the engine up, not keeping it cool.

water is one of the best fluid conductors... and the coolant and water wetter you should have mixed in with it are even better conductors of heat. they have plenty of time to collect heat, no matter how fast they are moving through.

and when they are forced through the radiator, they have plenty of time to shed it. period. no matter what speed the coolant is moving... it will spend the same amount of time in the block and radiator, as long as the circulation pattern doesn't change.

a thermo is important so your engine will heat up quicker, and that is all. that's why it changes heat up times for climate control.


Why is a 160 tstat's hole smaller than the factory one then?
Old 08-09-2008, 12:50 PM
  #32  
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Originally Posted by TWS
I echo the posters who said the coolant needs to "sit" in the radiator to shed heat. If it is constantly circulating (no T-stat) it does not shed as much heat as it would during (normal) cycling between the radiator and the engine.
Those who say the coolant will shed less heat if it spends less time in the radiator are right.

But, when flow is increased, the coolant makes more passes through the radiator than when flow is slower. The total time spent in the radiator ends up being the same.
Old 08-09-2008, 02:22 PM
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I remember an Oldsmobile in my past that ran cooler in the Arizona heat with a thermostat. That's a far cry from the cooling systems of the LS1 though.

Question for those who are ditching the tstat on an lsx style engine...what are you doing with the bypass passage? Are you blocking it off or just letting the coolant find the path of least resistance?
Old 08-09-2008, 08:42 PM
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Originally Posted by shannon
Why is a 160 tstat's hole smaller than the factory one then?
I'm not sure how this relates to my post, and I can't honestly say I've ever compared the two to see a difference.

I couldn't even say I know what temp the factory tstat opens at.

But it may just be the manufacturer of the tstat is different... and so they use different amounts of the heat sensitive material (wax most of the time, iirc)
Old 08-09-2008, 08:48 PM
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u need one to slow the hot water down
Old 08-09-2008, 09:49 PM
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Originally Posted by AxisOfOil
I'm not sure how this relates to my post, and I can't honestly say I've ever compared the two to see a difference.

I couldn't even say I know what temp the factory tstat opens at.

But it may just be the manufacturer of the tstat is different... and so they use different amounts of the heat sensitive material (wax most of the time, iirc)

The difference in size is comparable to half dollars and quarters...I was told that the smaller size keeps the water flowing slower absorbing more heat to get rid of more quickly.....
Old 08-09-2008, 10:48 PM
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Originally Posted by 08-4door
u need one to slow the hot water down
lol you really don't. You won't overheat without one, but run cooler.
Old 08-10-2008, 11:00 AM
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No one seemed to mention the cylinder and ring wear that'll come from not letting the engine hit its operating temperature.
Old 08-10-2008, 11:31 AM
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ItsNotStock;9684467]Keep the thermostat. Yes, your car would run cooler. But I doubt you would notice any gains power-wise. And I personally would be afraid of damaging engine components from lack of proper warm-up. Do you start your car in the morning and floor it? No. Unless your car is track-only I would leave it alone. Run a summer mix and try to worry about the bigger stuff.
I did. No one paid attention
Old 08-10-2008, 11:52 PM
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no, we didn't pay attention.
i felt we answered his question early on... then hijacked the thread.



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