Some Learning For all About Actually Removing T-Stat

[ubtripn]

I know this is a hot topic and that there are two camps, I am not trying to start a war. Instead I am going convey what actually happened when I removed mine.

I am currently battling over-heating, one thing I tried was removing the T-stat which worked on 6 other vehicles in my life. When I removed it on this crate engine it stays cool and eventually hits equilibrium at 150 degrees. However, if it is really hot out (over 90 degrees out) the heat of all the coolant slowly rises until out of control. The following statements are true:

1. With T-Stat in I would average 180 degrees and only creep up at intersections then it would return to 180 fast once RPM's were increased. I.E. A restriction in the coolant flow does indeed allow for the coolant to remain in the radiator and be cooled more. Still I would start rising at intersection but at a slower rate.

2. The temp does not drop fast with an increase in RPM's when engine is hot and the T-Stat is out.

Turns out both sides are right. Removing it does cool the engine but reduces engine efficiency and increases wear and only worked for me when it was under 90 degrees out. Removing it also does not allow for control when it is really hot out.

I was surprised to see that it could over heat with the T-Stat out and a new radiator and water pump.

On all other non-v8's, removing the stat meant never over-heating.

This is just info for others to use.

I am still hunting for my equilibrium and am close. I DO NOT want to be watching my temp gauge all the time, new cars never seem to have the needle move much. I am going to use an electric fan to hit my equilibrium.

[geezer#99]

Have you looked into an orifice plate?
I did, way back in time. Ended up with a 1/2 inch centre hole. Warmed up quicker and stayed around 180.
Not at your temps though. Nearer to 80 degrees.

[ubtripn]

I did consider that or a washer but I 160 T-Stat makes me run 180 perfectly, I just start heating up at intersections.

Apologies to the Moderator, I have two related (over-heating) threads, I started this one to share my experience removing the thermostat.

[Grumpy old man]

If your running a 180 thermostat and it gets hot at a light you have other issues like a clogged radiator or a worn water pump ,loose belts ,you need a thermostat in place to cool the engine and slow water flow between the engine and radiator ,fast flow can't pull off high heat in the engine .

[davepl]

Originally Posted by Grumpy old man

If your running a 180 thermostat and it gets hot at a light you have other issues like a clogged radiator or a worn water pump ,loose belts ,.

Agree entirely!

you need a thermostat in place to cool the engine and slow water flow between the engine and radiator ,fast flow can't pull off high heat in the engine

Disagree entirely! There's no such thing as "too fast" to transfer heat, since the "too fast" coolant is "rushing away" to be replaced by even cooler coolant, and there is no time at which the metal is not in contact with the coolant, unless it cavitates.

So long as there is no cavitation, the fastest possible flow with the lowest possible viscosity will return the greatest cooling. But you don't need that speed for any practical purpose, and a thermostat doesn't slow things down much.

Short version of the story is that your engine should cool just fine with a 180 or 195 T-stat, and if it's running hotter than the T-stat set point, it's really got nothing to do with the T-stat so long as it's opening when it's supposed to.

I don't want to rat hole on the "too fast" coolant thing so am content to agree to disagree on it.

[mike16]

Originally Posted by Grumpy old man

If your running a 180 thermostat and it gets hot at a light you have other issues like a clogged radiator or a worn water pump ,loose belts ,you need a thermostat in place to cool the engine and slow water flow between the engine and radiator ,fast flow can't pull off high heat in the engine .

since the pump and the radiator is new those causes can be eliminated. however even a new radiator may not flow the volume needed to cool the engine. it could be too small or maybe there are internal restrictions a result of ignorant manufacturing process.

the actualy too fast flow speculation is a myth that was put to rest back in the early 90's

new or rebuilt water pumps are built to a generic standard totally unrelated to the specs of the pump or the needs of the application. a new pump means nothing. better to pay 90 bucks for a new pump from a reputable manufacturer than 20 dollars for som genetic chicom junk. new does not mean better. the manufacturer needs to know what they are doing. many do not.

saw something on you tube where the lower radiator hose collapsed almost completely after hard acceloration and decceloration. do you have a coil of wire inside the lower hose at least to keep it from collapsding. cheap azzed parts vendors remove those coils of wire and sell them separately. back in the day they came with the lower hose. I make my own from stainless safety wire wrapped around a tube slightley smaller in diameter than the inside dia. of my lower hose. Dont know why manufacturers get away with that. What? too expensive to ensure a working product or customer satisfaction.

[ubtripn]

I do have the wire in the hose on the bottom but I could use a new upper hose, thanks.

[Stocker]

Originally Posted by ubtripn

I DO NOT want to be watching my temp gauge all the time, new cars never seem to have the needle move much.

FWIW, I heard this some years ago and have no idea if it's true or not. Maybe someone here knows for sure.

There's a reason the temp gauge in modern vehicles stays constant. As long as the actual temperature is within design limits, the gauge is designed to read at or near center. This is to keep people from worrying about normal fluctuations, especially if it involves running to the dealer to correct a problem that may not exist. Seems plausible, and I would assume that the gauge would report an actual overheating situation.

I am not suggesting this has anything to do with your overheating, only offering a possible explanation of how newer temp gauges *might* function.

[Grumpy old man]

Slowing the flow allows heat transfer to the coolant from the hot engine ,The slowed flow rate allows the heat to transfer OUT of the coolant in the radiator , without the ability of the radiator to pull heat off the coolant it would continue to rise until engine failure . Otherwise you wouldn't need a radiator or fan to improve air flow for heat transfer .

[mike16]

test your sender the wireing and the guage. boil the sender in water and hook up the guage and measure the temp of the boiling water. see if they are common

[garyd1961]

Do you have the heater core hooked up? If not do you have a by-pass hose hooked up? I had my heated core plugged off with a hole drilled in the thermostat. It would run constant most of the time but would randomly shoot over towards the hot side. I put a by-pass hose from the front of the intake to the top of the water pump and it runs constantly on the cool side now.

[davepl]

Originally Posted by Grumpy old man

Slowing the flow allows heat transfer to the coolant from the hot engine ,The slowed flow rate allows the heat to transfer OUT of the coolant in the radiator , without the ability of the radiator to pull heat off the coolant it would continue to rise until engine failure . Otherwise you wouldn't need a radiator or fan to improve air flow for heat transfer .

That's like saying you need to hula-hoop slowly so that the hoop has time to contact your pants and make friction. It might sound appealing, but the physics don't support it.

If you promise to read it, I write it. Agreed? Ok good, here goes :-)

Where is the coldest coolant? In the radiator.
Where is the hottest coolant? In the engine.

Your ideal cooling system would operate at infinite speed so that the same temp coolant was everywhere in the system at once. Conversely the slower the coolant flows, the more time the block and heads remain in contact with already-warmed coolant, sitting there waiting while cooler coolant is in the radiator.

There's no such thing as "too fast to transfer heat", because the coolant that's coming behind it is, by definition, cooler than what is at any point now.

Transfer of heat takes place at a constant rate for two materials and varies with how much temp difference there is. Your best cooling comes from the coolest coolant being exposed to the hottest engine parts, and cool coolant sitting in the rad does nothing to help that.

Now if you circulate the coolant so fast that it cavitates you'll get steam pockets that don't transfer heat worth a damn, so that's why I always add "without cavitation".

When I was a kid we had a solar heater on the garage for our pool... this was all homemade stuff and a hand-dug in-ground Sears round pool, but it was a cool solar heater. My Dad made us run out every 30 minutes and plug it in. He wanted the water to get hot in the heater and then pump it into the pool. He was mistaken (except that electricity to run the pump isn't free). The best heating would keep the coldest pool water in the heater at all times, just the reverse of the situation we're talking about. It'd pick up the most heat the fastest.

If you do not yet agree, perhaps it would be better if I understood the notion of "too fast to transfer heat" when there's nothing but just-as-cool coolant following behind it. There's never a time when the hot surfaces aren't in contact with coolant, so the cooler, the better.

[davepl]

FWIW, I haven't read the whole thing yet, but here's a page from Stewart who makes cooling systems:

"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. "

They have a whole page on it:

http://stewartcomponents.com/index.p...ormation_id=11

[VetteVet]

Originally Posted by Grumpy old man

Slowing the flow allows heat transfer to the coolant from the hot engine ,The slowed flow rate allows the heat to transfer OUT of the coolant in the radiator , without the ability of the radiator to pull heat off the coolant it would continue to rise until engine failure . Otherwise you wouldn't need a radiator or fan to improve air flow for heat transfer .

I learned this the hard way back when I was a young buck. My 69 charger 383 started overheated one day while I was on vacation in South Carolina, in Columbia. I figured the thermostat had stuck so I removed it and all was well, until I got into heavy traffic and the temp started inching up. It actually got into the hot area so I had to pull over and shut it down until it cooled off,

After about 30 minutes or so I started it up and it was fine until I hit some more traffic and it started climbing again. I was able to clear traffic and get onto the interstate where it immediately dropped into the normal area. As soon as I could, I bought another thermostat and installed it and no more problem.

My opinion on this agrees with Grumpy's in that the coolant flow increases through the system just enough so that it gradually rises the temperature until the system can't manage to keep it cool, but for a different reason.

The problem isn't so much the speed of the coolant but IMO it is the amount of airflow that is pulled through the radiator is not proportional with the amount of coolant flowing in the system. Like Grumpy said, overheating is caused by numerous things .

The new automobiles got away from the engine controlled fan speed for just this reason. They can run smaller heat exchangers without relying on engine speed for airflow control at idle, by using electric cooling fans to pull more air through the heat exchangers at low engine rpms without worrying about coolant flow rate. This allows cars and trucks to sit in traffic at idle for longer periods without increasing temperatures.

[Grumpy old man]

This is one of those topics that has multiple opinions and I'm just referring to my own , without a thermostat or a flow restrictor it's going to overheat . That's just my own seat of the pants in the driver seat opinion .

[jjzepplin]

I think we should find out what type of fan you are using and are you using a fan shroud?
I ran no thermostat in my engines in S.F. Calif but it was mostly cool outside except for a few days in the year.
That was when I was a kid. I would never do that now.
We all assume that no damage was done to your engine during the overheating.
I would run the correct thermostat and fan and shroud and radiator. If you still have issues use a electric helper fan for traffic.
Oh and I run the biggest radiator I can.
What engine and how many rows is your radiator?

[Travis1974]

This may be coming WAY out of left field but here is what happened to me.
When I first built my 72' it had a crate engine. I drove it most of the summer in central Texas and fought overheating. Especially if I was sitting at a light. It ws boiling the gas in the fuel filter and vapor locking too. I went round and round with the cooling system and heat shielding all the lines. The works. No help.
Then one day I had to pull over in traffic to let it cool down and this good ole boy pulled over to help. I told him all about it and he said "its your timing". What? no way. I am dialed in exactly to factory specs. checked it 3 times. He said "trust me, I do nothing but build old chevy engines on these old trucks. The timing is for 1972 gas. You are running 2014 gas. You need to advance the timing 10 degrees." "trust me". I had nothing to lose and went home that night and advanced the timing like he said.
2 years later she still runs PERFECT. dead center temp even in 100 degree temps and in traffic.
Try it if all else fails

[special-K]

I need to read back through your other thread. It could be a bad new part. It sounds like something to do with the fan or clutch since it's when there is no air flow. That is where the fan and comes into play. Don't need a fan going down the road*, it compensates for lack of air flow through radiator. Another possibility is your crate engine is making excessive heat, enough to out do a healthy cooling system That is possible, say if there is a cracked ring causing excessive friction. Often, the first thing to check is the newest part. In a perfect world that would be the last thing, but we know how the world works. Pretty good, but nt perfect all the time.

* In most cases. But going up grades or hauling a lot of weight can require help from the fan.

I had a flex fan on a truck. I was getting hot coming home, wrking long days 7 days a week. No time to get into the issue, had to work around it. My ride home is a gradual uphill grade on the interstate. I am the 4th exit up the road. The temp would get up there by the second exit, so I'd pull off and take that 2-lane north. Just the lower speed and not a constant climb allowed the temp to stabilize, but still up there. Then it drops into a cool river valley I could drift down into. By the bottom the temp was cooled to normal, which is way left on gauge. Gotta climb back out of that whole straight, steep, but short. Temp would get up there, but not as bad as on interstate. Leveled off and shortly made a left heading westward. Temp maintained in a higher than normal range, but not so bad. Lots of dips and curves where I let off the throttle. I cross the road that is the 3rd exit and continue west on the road that takes me to the road that is my exit. This road shortly dips down another big valley and temp gets totally cool again. Then up steep grade with temp going up, leveled off, another cooling dip and one more down/up repeat till I get to my road off the interstate, north as I needed to be, straight across and down into my valley where I made it home at normal temp. 70-80 hours of hot hard work a week and two kids kept me too busy to check into it for a long time. When I finally got into it I discovered the blades had fatigued and not much left. A real simple fix. Boy did I feel dumb. But I am an expert at getting my junk back home and I kept the wheels turning, bills paid, and family happy.

[ubtripn]

I bet that is true with new cars and I will do the recommended sending unit test, great advice, thanks.

I am running an new 4 row rad, new shroud, the ONLY thing not correct is where the fan sits in the shroud. I read that I must get the fan 1/2 inch from the rad for the metal strip n the clutch to work and then read that I must have the fan about 1/2 into the shroud opening. I cannot do both. I bought the ac shroud which is pretty deep. Unless it is above 95 degrees, my truck, with a 180 T-Stat runs perfect, but we have 3-4 weeks in Boise where we flirt with a 100 out and the traffic is bad. I am going to try the jeep grand Cherokee 19 in curved blade fan mounted in the shroud hole and remove the mechanical fan to see if I can get in front of the problem. Oh, the core is hooked up as well. I am going with the jeep electric mod because I would like to not mess with the mechanical fan bolts anymore as well. Installing that fan in the shroud with the spacer takes an octopus and in the future when I need to work on the engine I just want all that cleared out.

One other question, these t-stats look cheap, the crate engine though came with one that had a cylindrical bottom, is this a better t-stat. What is the best?

The funny thing about t-stat verses no t-stat is that both sides are right, it just depends on the situation. At least for me that is what happened like the gentleman with the charger.

Special K - I agree, I always look at the last thing changed. Here is some more history, I have been fighting running rich. It was parked running and I left black residue on the curb so I adjusted the Edlebrock 650 and the timing - I really believe I found the sweet spot. I am still running a little rich though because I need no choke in the morning so I put a pressure regulator on it. I have no idea where the timing belongs on this mystery engine. I got a good deal but no spec sheet so I rotated the disti until it felt right then backed it off a little. When I did this the disti was almost hard over but like I said I backed it off. The throttle response it fast as you can get your foot down and just as fast returning to idle. Seems to be running strong.

[Mrturner1]

Originally Posted by ubtripn

I bet that is true with new cars and I will do the recommended sending unit test, great advice, thanks.

I am running an new 4 row rad, new shroud, the ONLY thing not correct is where the fan sits in the shroud. I read that I must get the fan 1/2 inch from the rad for the metal strip n the clutch to work and then read that I must have the fan about 1/2 into the shroud opening. I cannot do both. I bought the ac shroud which is pretty deep. Unless it is above 95 degrees, my truck, with a 180 T-Stat runs perfect, but we have 3-4 weeks in Boise where we flirt with a 100 out and the traffic is bad. I am going to try the jeep grand Cherokee 19 in curved blade fan mounted in the shroud hole and remove the mechanical fan to see if I can get in front of the problem. Oh, the core is hooked up as well. I am going with the jeep electric mod because I would like to not mess with the mechanical fan bolts anymore as well. Installing that fan in the shroud with the spacer takes an octopus and in the future when I need to work on the engine I just want all that cleared out.

One other question, these t-stats look cheap, the crate engine though came with one that had a cylindrical bottom, is this a better t-stat. What is the best?

The funny thing about t-stat verses no t-stat is that both sides are right, it just depends on the situation. At least for me that is what happened like the gentleman with the charger.

Special K - I agree, I always look at the last thing changed. Here is some more history, I have been fighting running rich. It was parked running and I left black residue on the curb so I adjusted the Edlebrock 650 and the timing - I really believe I found the sweet spot. I am still running a little rich though because I need no choke in the morning so I put a pressure regulator on it. I have no idea where the timing belongs on this mystery engine. I got a good deal but no spec sheet so I rotated the disti until it felt right then backed it off a little. When I did this the disti was almost hard over but like I said I backed it off. The throttle response it fast as you can get your foot down and just as fast returning to idle. Seems to be running strong.

You COULD do like I did when I had a mystery engine and tear it all down in a thread with pictures and then spend 2000 bucks getting it to where "I think" it should be, and end up with a big ole cam and Holley DP, a giant stall converter and a 3.73 mink spool lol but boy is she fun comin out of a slow turn!

[Andy4639]

I read that I must get the fan 1/2 inch from the rad for the metal strip n the clutch to work

??????
I've never herd of this one before.

[special-K]

350 timing is all about the same, isn't it? I've never known it to be so crucial with stock to mild cam. I can tune by ear better than some using a scope. I have stories on that, too. If it ain't pinging, idles smooth, and is snappy you should be fine

[jeffahart]

Originally Posted by davepl

That's like saying you need to hula-hoop slowly so that the hoop has time to contact your pants and make friction. It might sound appealing, but the physics don't support it.

If you promise to read it, I write it. Agreed? Ok good, here goes :-)

Where is the coldest coolant? In the radiator.
Where is the hottest coolant? In the engine.

Your ideal cooling system would operate at infinite speed so that the same temp coolant was everywhere in the system at once. Conversely the slower the coolant flows, the more time the block and heads remain in contact with already-warmed coolant, sitting there waiting while cooler coolant is in the radiator.

There's no such thing as "too fast to transfer heat", because the coolant that's coming behind it is, by definition, cooler than what is at any point now.

Transfer of heat takes place at a constant rate for two materials and varies with how much temp difference there is. Your best cooling comes from the coolest coolant being exposed to the hottest engine parts, and cool coolant sitting in the rad does nothing to help that.

Now if you circulate the coolant so fast that it cavitates you'll get steam pockets that don't transfer heat worth a damn, so that's why I always add "without cavitation".

When I was a kid we had a solar heater on the garage for our pool... this was all homemade stuff and a hand-dug in-ground Sears round pool, but it was a cool solar heater. My Dad made us run out every 30 minutes and plug it in. He wanted the water to get hot in the heater and then pump it into the pool. He was mistaken (except that electricity to run the pump isn't free). The best heating would keep the coldest pool water in the heater at all times, just the reverse of the situation we're talking about. It'd pick up the most heat the fastest.

If you do not yet agree, perhaps it would be better if I understood the notion of "too fast to transfer heat" when there's nothing but just-as-cool coolant following behind it. There's never a time when the hot surfaces aren't in contact with coolant, so the cooler, the better.

Wow, that's the kind of tripe that usually keeps me away from forums.

The topic of no thermostat is a non topic. Else, pull your thermostat, and run your pretty little truck up the grapevine this weekend. It will be a hundred plus this weekend. Let's see the no thermostat crowd run the grapevine with out a stat.

OP, put in your thermostat and get your cooling system running properly. And of course, all things equal. If your running some performance configuration or a top fueler then you need to make the adjustments for your modifications/configuration. But if that were the case I'm guessing you probably would not have posted this.

Temperature activation is the basic definition of a thermostat. Use one!

[Stocker]

Originally Posted by ubtripn

I read that I must get the fan 1/2 inch from the rad for the metal strip n the clutch to work

No, no, no, and no.... dunno where you read that but it is 100% wrong.

and then read that I must have the fan about 1/2 into the shroud opening.

Yup, that's about right and will ensure max air is pulled through the radiator.

[dmjlambert]

Originally Posted by Travis1974

This may be coming WAY out of left field but here is what happened to me.
When I first built my 72' it had a crate engine. I drove it most of the summer in central Texas and fought overheating. Especially if I was sitting at a light. It ws boiling the gas in the fuel filter and vapor locking too. I went round and round with the cooling system and heat shielding all the lines. The works. No help.
Then one day I had to pull over in traffic to let it cool down and this good ole boy pulled over to help. I told him all about it and he said "its your timing". What? no way. I am dialed in exactly to factory specs. checked it 3 times. He said "trust me, I do nothing but build old chevy engines on these old trucks. The timing is for 1972 gas. You are running 2014 gas. You need to advance the timing 10 degrees." "trust me". I had nothing to lose and went home that night and advanced the timing like he said.
2 years later she still runs PERFECT. dead center temp even in 100 degree temps and in traffic.
Try it if all else fails

I think this is one of the most interesting posts in this thread. I'm bookmarking for future reference.