First off. In the original thread nothing was decided, bickering started and Breathment locked the thread before the content got out of hand. I totally agree and it was the correct action by the Moderator. I apologize for any misunderstanding, I did not or ever will attack or single out a person on this board, I abide by all the rules set by TGO administration. I do along with the other TGO members however have the right to disagree fully with false information given at any time to protect the integrity of this board. I believe this topic must be continued to resolve in an orderly and FACTUAL manner if allowed by the Administration.


SSC

 

As stated before, removing the T-stat will allow coolant to flow unregulated, not allowing it enough time to properly cool in the radiator causing the engine to run hotter.

This is debated, not on this board but in text to. I had the same textbooks at WT that stated removing the thermostat will not cause an engine to overheat. The problem with this statement is an engine will run hotter but will it overheat? It is possible. In my experience the engine runs too hot to even continue to run it. Text on the net from a reliable source not by SSC.

Thermostat


The automotive thermostat controls the flow of coolant through the motor. As the temperature rises the thermostat opens, to allow the coolant to flow from the engine into the radiator. This flow is crucial to maintain operating temperature for fuel efficiency, driveability, and engine performance. The coolant flow is restricted when the engine is cold, and increased when the engine is hot. Many people, not mechanics, believe that by removing the thermostat, the engine will run cooler. When it really makes the engine run warmer, by not restricting the flow of coolant through the radiator. Believe me, your engine needs a thermostat !
http://www.dbmechanic.net/cooling/stat.htm

I'm am not affiliated with the site which this information was retrieved except for the fact that I am ASC certified but thats neither here or there.

 

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This is a dead issue it was ended, if someone can not accept the ending because it is not what they wanted too bad. No thermo will NOT overheat your car. The cooling system is closed loop constantly going through the engine and rad, all a thermo does is set the cooling system minimal temp. thats it. It does NOT keep coolant in the rad to "cool it down" If you remove your thermo then the coolant will run constantly through the motor and rad constantly cooled by the outside air temperaute their for getting too cold (as it did in my car when it had no thermo in it) So since the coolant is cooled by outside air temp, in order for your car to over heat without a thermo you would have to have a cooling system problem , blocked rad fins, cooling passages etc. Or the outside air temp would have to be in the hundreds.I am not speaking from some stuppid ******* washer experament or from a simple minded guess. I have exp with no thermo in my own car. If a thermo was put in place to keep the coolant in the rad to "cool off" then dont you think the manufacturers would make the maximum engine coolant temp on them instead of the minimal cooling system temp? Who ever can not understand how simple this is really shoud not be working on his or her car. PS just because someone makes a website and says they are ase (or even if they are ase i have ment some ase people who are idiots)doesnt mean sh*t. I have had no thermo in my car driven it 150 miles non stop got out opened my rad and stuck my finger in the warm coolant.

 

Actually this is where I base my information from.



br()bert

As stated in the original post, with X circulation and certain RPM driving its very possible to drive without the engine running hot, its all a matter of flow. Your cooling system without the t-stat flowed at a rate which allowed the coolant to actually cool too much, making the car run cooler..Yes? Once again this means the rate which coolant travled through your cooling system was -X and cooled too well, this is not always the case. I assume there was no pressure in the system?

Heres somthing I found kinda interesting, most important its true.


What makes this important is that the higher the temperature of the coolant is, the greater the temperature gap between it and the air temperature is. This is the principle that causes the cooling system to work; the hotter the coolant is, the faster the heat in it moves to the radiator and the air passing by. So, a cooling system under pressure takes heat away from the engine faster, which makes it more efficient.

http://www.musclecarclub.com/library/tech/cooling.shtml

Its all part of a system, when you remove parts of the system you cannot predict function. I have generally seen systems get hotter as a result off removing the t-stat. That may not be the case 100% of the time but in general coolant temp increases.

 

yes the system was pressurized and no it did not overheat. Im tired of this subject. its dead. already came to a conclusion before it was closed thanks for the coments though. Like i said before their is still people who think the earth is flat.

 

Just read it.....

 

cont..

 

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exactly, it protects from overcooling Just as underlined in red, the book actualy made overcooling in bold not me, I just underlined it with red for those who wouldnt take the time to read the whole thing.

 

 

i have an 87 formula with a 350 and a 5-speed (yes i know it didnt come that way it had a 305) i just found out that i had been running my car with no thermostat for awile and i been having problems. In the summer here in texas its 95-110 with the heat index of 110 to 130 so it gets pretty hot. My car would try to run 220to240 all the time i would have to baby it just to keep it from over heating feathering the throttle. and thats with my electric fan hard wired to the key with a brand new fan motor,new aluminum rad,new water pump, and 3000 miles on a new motor. now its winter and my car runs 130 to 160 no matter what i do i can drive for 2 hours 3,000 and it wont pass 160 now u tell me its okay to run without a termostat i cant use my brand new a/c and i cant use my heater?

 

what the hell are you talking aboout? No one said to run your car without a thermo.

 

it was like that when i bought it i have just been fixing the problems sense i was just saying what happend to me and what can happen to someone else if they do it.

 

I understand the point your making, but would like to add that a hard wired fan isnt the best. At highway speed it is actually detrimental to flow and will make your car run hotter.

You might want to invest in a $5 toggle switch

 

I dont think a toggle switch is the best either. Do a search on here and see how many people talk about them burning out constantly. I had my fan ran like that when i first got the car with thick wire. It got old VERY fast. So i went out and bought a hayden adjustable fan switch and a relay. Its much better now.

 

 

My 89 formula runs between 220-240 year round. I believe that is the normal operating temp. I had another Formula in 1998, and it was the same(220-240) Both cars had dual fans with the stock temp switches and relays(fans kick on at about 235 untill the temp drops to about 220, so not to worry. I used to think that its too hot, but that is how Pontiac designed it, so i left it alone. By the way, my heat in the car works very very good as a result.

 

I didn't see the original post in the other thread that mentioned washers inplace of thermostats. Using washers in place of thermostats was an old dirt track trick. It got you up to your best operating temperature but couldn't stick like a thermo. (Yeah people thought about overheating without one even 20 years ago).

We found that our heating problems went away if we removed the thermo completely. Of course we were running a real Indian motor, not a Chevy.... The washer thing seemed to work fine for the other guys.

Your computer controls are set to run best in a particular heat range. Unless you modify your chip, you should leave the stock temperature thermo in the engine.

Another thought: I wold run a seperate relay for each electric fan you may have installed. Even though the rating of the relay may be high enough for two, I've found the relays don't burn out if you only run one fan per relay. currently I am running a small electric fan and a large electric fan on each relay (4 fans total) and it hasn't burned out a relay in three years. Running two large ones on a 30 amp relay fried one in a year. I have the relay for two fans tied into the factory relay (using it as a trigger only) and two hooked up to a thermostatic fan switch in the head that comes on at 205*..... Still have heating problems in the summer with the A/C on....

 

Just to toss my own .02 into this mix...

If you've got a radiator that can sufficiently remove heat energy from the water in ONE PASS, without sitting in the radiator - then you will run cooler with no thermostat. All the heat going into the water is removed quickly, at once, in the one pass it makes through the radiator.

If you've got a radiator that CAN NOT sufficiently remove heat energy from the water in ONE PASS, then the thermostat's job is to close, doing two things -

1) The water in the radiator sits there momentarily. The incoming cool air (I think we can all agree - no airflow = overheating) continues to extract heat energy from the water. The thermo opens, and the cold(er) water moves along, while the hot water moves into the radiator. The cold water hits the thermo, closes it, and the cycle continues.

It's just simple Physics, really.

 

Yes Doward, thats what some of us were trying to explain in the first thread.

Most if not all factory style radiators cannot cool in an open cycle. The coolant needs that cycle time to cool. Running without a t-stat allows coolant to flow ungregulated. Without X heat transfer a system can overheat.

 

I didn't read all of this post because I didn't feel like it. This thread should be made a sticky for all of the people who are new to cars who may actually think that no stat or really low temp stats are better.

Here's my experience. I orginally used a 160* stat with my new 383. I experienced all kinds of running too hot. Not too hot to do damage, but hotter than I wanted to see. I have also had installed an aluminum high flow pump and Griffin rad. Turn fans on at appropriate times, still would run up to about 200* when sitting in traffic.

I recently changed to a 180* stat and now I don't see over 190*. The stat being open all the time, like how I had, was similare to having none at all.

Just another log on the fire...

 

First off, you guys are missing the ball on one thing.

T-stats secondarily have another function, which if you insisit on running tstat, you should pay attention. Not only do thermostats allow the coolant to maintain a temp (i think we all agree on this no?) they also pose a restriction, even when open!

so why is this restriciton necesary? easy... steam pockets can form in the cylinder heads in hot spots. the restriciton increase the pressure within the blocks cooling areas thus forcing water into these hot spots. These hot spots can be very bad, cause detonation at its worst, or possibly cause a headgasket failure, or cracked heads... so those of you with no stats should consider placing a restrictor made out of sheetmetal with a hole that is the same size a US quarter. this seemed to work the best for us in the nascar late model we had raced.

Why do people not have some of the problems i mentioned? well, your simply not running your car hard enough for these problems to occure... this happenes in race engines... but those of you who run without a stat or a restrictor plate are asking for trouble should you get into a upper rpm jaunt for an extended amount of time.


My technique has always been to use a 180* thermostat, and on the edges, the ones that immediatey surround the existing hole, i drill 2 or 3 small (like 1/8") holes... this for me i have found has dramtically reduced my engine temps, and, made the temps much more stable in hot weather, while still allowing for the coolant to get up to temp. (we all know that engines are machined for certain tolerances produced by heat and that runing a motor colder than it could be is not all that great for it)

 

A thermo is made to maintain the coolants minimum temp. When the coolant reaches a set temp (ei 180 thermo opens at 180 etc) it opens and lets the coolant into the rad to cool, when the coolant cools to much ( below 180 with a 180 thermo) the thermo closes and lets the coolant heat up again , over and over this is the whole system. All this is explained in text books and by the auto makers. So if you remove your thermo and run hotter you have a cooling system problem, plain and simple, No ******* bs or backwoods voodoo. I dont see why this is so hard to understand really.

 

Whew I really started something huh?

Well since I started the original post Ive done a bit more actual research and have some things to share with you all. Ill try to lay it out as simple as possible:

Car1: carbed 1983 camaro, 350ci stock Van motor, 2-core factory radiator, Regular rotation factory Water Pump, No Thermostat, Flex-a-lite Dual electric fans

Parked:
From a cold start, engine heated up normally and continued to heat up until 190* was attained and the fans kicked on and cooled to 180* then kicked off.
City Driving:
Identical to parked

Highway Driving:
Engine bypasses 190* fan turn-on point and continues to 210* where it teeter totters depending on road speed. exceeding 80MPH seems to push it past the 220* mark. Car does have an Air-dam.. but in questionable condition?

Car1 Same as above but with a 195* thermostat
Parked:
From a cold start, Engine seemed to heat up much quicker...
The fans began acting weird, they would kick on then off real fast... then back on..? This stopped after a few minutes..

City Driving:
Car would get hotter than normal (without T-stat) but wouldnt pass 200*. I beleive this is because the T-stat is a 195* and the fans are set to kick on at 190* which wouldnt work out if the T-stat was closed...

Highway driving:
Car still got very hot, 210*, but wouldny budge any further.
It appears the T-stat helped keep the highway temps slightly lower but caused the city and parked temps to go up...

Car 2: 1989 camaro 355 TPI(see sig), Highflow reverse roation pump, Factory RS radiator (1core i beleive?), No T-Stat

Parked:
Car would take a long time to hit operating temp, but once there it would be very hard to cool off.

For instance it would get to 192* (fan on temp) and the fans would kick on, but it would continue heating up to 199~* before it began to drop down to 186* (fan off).

City Driving:
Same situation, Except it maybe cooled a teeny faster.

Highway Driving:
Car would not get past 170*F even with fans off. slowing to under 50MPH caused it to begin to heat back up though...

Same car, 195* T-stat
Parked:
Heats really really fast! Then cools off REALLY fast! I wana post that datalog.. It would get to 200* real quick then jump back down to 170~ish then back up to 190~ish then back to 180ish Liek a pingpong ball... then finnaly stabilize around 190* parked.

City Driving: Car Fans switch on at 190* but engine would heat to 198-200* regardless then cool back down to 185* suddenly. lather rinse repeat.

Highway Driving:
Again, car wouldnt see past 170*... With or without the T-stat it would just stay freaking cold on the highway.

Final test was I drilled 2 holes in the T-stat. Now it heats up slower, but no more ping-pong tempeuratures. it still runs super cool on the highway though.

I did some of these tests back in the old thread if you read it, but im posting all of them together now. Im going to mess around with my cooling system some more, I think theres a leak somewhere because it never seems to hold pressure even after it hits 200* the hoses are soft and i can open the rad cap.

 

Well last winter i took out my t-stat when i was on a trip (side of road) when it had become stuck. I was to lazy to replace and i had to warm th e car for ever and soon as i would get moving the temp would drop to nothing. i froze my but off for a week before i replaced.. dunno if it helps just my experence with out a tstat..

 

I run a 160 thermostat in the winter... so I have heat. I don't have one in the summer, and I can sit in traffic all day (with the fans coming on at 220, never sees any higher)

 

So your saying you run a 160 in winter and have heat?? Maybe after 15-20 minutes. I just swapped my 160(previous owner installed) for a 195 and my car is much more comfortable now.

Are you also saying you take out the t-stat in the summer? If so, your doing everything completely opposite of whats intended. Your cars cooling system "should" be able to sustain a decent temp in summer traffic, for a reasonable amount of time, if its up to par.

 

Yes, but I was always told that you get better coolant flow without it, and there isn't a chance for it to stick... so I take 5 min and pull it out.

 

 

one problem you may run in to is tthat when your car is below temp the cars computer will run in a defult state. (closed loop i think) which does not reed your sencors, and when your temp is up it will run in open loop (i might have the open/closed reversed) where it operates using all of the motors sencors. so running to cold is bad.. also when your motor runs that cold it will inject more feul to compensate for the cold. i got horrible gas milage when i had no stat in the winter....

 

I am not trying to start a flame war here, and if what you do works for you, right on.

You say you were always told you get better coolant flow without a t-stat. Well, sure, there is no restriction to flow. However, one of the key uses of a stat is to SLOW down coolant flow and maintain a minimum temp. With the coolant just flying through the system it can't absorb as much heat in the heads and from around the cylinders. Also, it won't sit in the radiator as long to release that heat.

For whatever its worth...actually I think someone posted the exact same info further up!!

TGO.org RULES!!!!

 

my car has no thermostat, and it runs at a constant 150-160 degrees all the time, unless its really hot it sometimes hits 180 degrees

its driven almost daily during the summer, sometimes over 100 miles a day for shows, meets, and racing

its never overheated before....

besides its common knowledge, if your car overheats for no reason (radiator is fine, pump is working) your t-stat is bad, so you open it up roadside, and throw it out.....then drive home safely and get a new one

cars that dont run in cool weather and heat up to operating temperature quickly dont really need a thermostat.

as for the argument that the coolant flows too fast, all that can do since its a closed loop system is reduce the average temperature of individual qty's of fluid. the amount of heat transferred from the engine to the coolant is the same overall....just less per unit of coolant, because less heat is transferred, it then conveniently requires less time in the radiator to return to temperature, and the cycle repeats....

 

Some running examples

 

Here's something for everybody to chew on.
Q=m*Cp*(Delta T) where Q is actually Q dot measured in kWatts. m is the mass flow rate in kg/sec (also L/sec if water), Cp is the specific heat of water which is about 4.2 depending on the temperature, yes, it depends on the temperature but doesn't change much until it's form of matter changes to either ice or vapor, and T is in degrees C or K, whichever.
Now if you noticed, Q is heat. So the more Q you remove the better, now for Delta T, let's say the radiator can remove 10 degrees or whatever, let's just say for simplicity it's constant (which it is if the same mass flow rate is seen on the air side). So now we're left with m, beautiful m. If you increase the mass flow rate of coolant though a system then Q will also increase, hence the heat exchanger is removing more heat from the system! Now I can go into even greater depth on how the cooling system works but I figure this is enough to make my point. No thermostate or a broken thermostat in the open position will always cool the engine down! The only instance is if you have a freak situation where the water pump needed the restriction to keep the block pressurized to reduce nuclate boiling but again, mass flow rate goes up and you should have no problems since more mass is harder to boil with large amounts of turbulance found inside a waterjacket. UNLESS your waterpump is a completely undersized POS, then that again is a freak situation and you need to upgrade!

 

I'm going to say a few things, then bail from this thread. Its obvious you can't change some peoples minds:


1) Your car runs open loop until coolant temp reaches a certain
point. If your car doesn't reach that point, you'll never hit
closed loop.
2) Emissions are directly effected by changing operating temp
of your vehicle.

I've read a lot of interesting theory's here. Here is mine:

It takes a certain amount of energy to change the temperature of water. Take a blow torch, and hold it over the cold water pipe on your faucet with the water on full blast. Does the water get warm? Not really no. The water moves quickly and does not absorb the heat energy. Now turn the fauctet almost off, and hold your hand under it. It gets warm, warmer, and eventually hot.

How long does 1 quart of water take to boil in a saucepan with the stove at a given temp?

Whats my point? Well, in my opinion, which can be debating you have two issues. 1) The fast moving water might not pick up the heat from the engine, resulting in engine overheating (even though the water temp is fairly low!), and the heat that _IS_ in the water, may not be expelled correctly through the radiator.

Now, I believe the law of physics proves that water will cool down quickly, because air absorbs heat quickly therefore it maybe true that running NO thermostat may NOT effect the procedure of COOLING THE WATER DOWN. However, I do feel that physics proves to us that we may never HEAT THE WATER UP to begin with!

The fact is, with the cold water moving quickly through the system, the iron block, rods, crank becomes a better heatsink - which will then expell the heat into your engine oil. Perhaps you folks removing your thermostat and running 160-180f coolant temp, should check your oil temp?

Again, I don't care what you do with your car. I care about what I'm doing with *MY* car.

-- Joe

 

if your car isnt computer controlled it doesnt matter.......

secondly, the speed of the water has nothing to do with cooling, volume is the determining factor as to how it will cool the engine, it doesnt matter how long its in contact with the water jacket, all it means is that less energy is absorbed per unit of water.....but the flow of the water is greatly increased, therefore more water, is coming through the jacket faster......so the equation balances itself

like i said before, my car has no tstat and it runs at like 150 most of the time

 

That would be a great theory except for one small problem. The cooling system is a CLOSED LOOP SYSTEM. Unfortunatelly, the water that comes away from the motor doesnt flow down a drain, it just goes back into the motor. take your faucet draining example and loop the water back into the faucet. eventually, it gets hot because its not dissapearing down the drain. that would be a closed loop example. having it go byebye is a completelly different story.

Good try, though.

 

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It is entirely dependent on how much heat your radiator dissipates. If it is lacking, the motor will eventually overheat (with no stat) If it has tons of cooling capacity, or just enough, it won't.

 

Just curious, are you guys measuring engine temp or coolant temp? To end the debate I would suggest that you all take your temp readings from the head, where the most heat is generated. This should show how much heat is being transfered from the engine to your cooling system, which is all that counts anyway.

 

This thread need to DIE already!
This isnt a matter of opinion, its factual, remove your thermo=run cooler. If your car overheats without a thermo you have cooling issues.