How hot is too hot?

[Hemi Rebel]

I have a 400 in my 64 Belvedere with a 22 inch 3 core rad, 160 thermostat, fan shroud and electric pusher fan as well as the factory clutch fan. I'm seeing consitant temps around 210-225 dgrees in town on an evening cruise. Out on the highway it is around 200 Is this normal or a bit high? The car has yet to puke it's coolant or anything but this seems warm.

assuming the guage is correct, I would check the fan setup you have. Probably lose the electric fan and make sure the clutch fan is operating like it is supposed to. How many blades does the clutch fan have? this http://www.summitracing.com/parts/DCC-4120758/ should be all the fan you need.
I wouldnt be so much concerned about what temperature consitutes over heating or what is a good temp to run at as I would be about why your particular engine is at the temps it is at with a 160 thermostat. A good cooling system should keep temps around 5 to 10 degrees of t stat opening. the radiator sound like it should be plenty. So why can't it dissipate heat? If the heat is transfered to the coolant, and the coolant gets circulated through the radiator where is dissipates the heat to the surrounding air, somewhere in this chain of events is the problem. Either the circulation of the coolant is restricted or not moving fast enough, the air through the radiator is resticted or the cooling system capacity is not enough. The radiator sounds big enough and it should hold enough coolant. What concentration of coolant do you have?
What is the clutched fan doing? At 200 plus it should be engaging for sure. Is it close enough to the rad to get the air coming off of it?
Or better yet, is the electric fan motor sitting directly in front of the rad dead center and the clutch is on the the other side in line with the electric motor. If so, the motor is blocking airflow to the clutch. that coiled piece of metal needs to have air coming off the rad to react to.

 

[69Bee]

Water boils at 212 deg. fahrenheit @ sea level. Yes I know we're dealing with a closed system but when I see any needle going past 190 -195 I'm starting to worry!

Try looking up how pressure affects the boiling point of a liquid in a physics book. That is why the cooling system is pressurized; it raises the boiling point to approximately 265 degrees Farenheit.

All of my Mopars have run in the 195 to 210 degree area. I have always used either 195 or 180 degree thermostats, and I really suggest you do the following:

1) Get a 26" radiator (your loosing too much cooling area with the 22")
2) Get rid of the electric fan
3) Make sure the fan clutch works, or replace with a Mopar HD unit
4) Make sure the fan shroud is correct for you application, and that the fan fits in it correctly
5) Install a 195 degree thermostat as designed by Chrysler Engineering

Your temps are not horrible, but these fixes should bring it down a little. If you are not using synthetic oil, you might think about it. I lost about 10 degrees when I changed over from regular oil.

 

[Hemi Rebel]

Try looking up how pressure affects the boiling point of a liquid in a physics book. That is why the cooling system is pressurized; it raises the boiling point to approximately 265 degrees Farenheit.

All of my Mopars have run in the 195 to 210 degree area. I have always used either 195 or 180 degree thermostats, and I really suggest you do the following:

1) Get a 26" radiator (your loosing too much cooling area with the 22")
2) Get rid of the electric fan
3) Make sure the fan clutch works, or replace with a Mopar HD unit
4) Make sure the fan shroud is correct for you application, and that the fan fits in it correctly
5) Install a 195 degree thermostat as designed by Chrysler Engineering

Your temps are not horrible, but these fixes should bring it down a little. If you are not using synthetic oil, you might think about it. I lost about 10 degrees when I changed over from regular oil.

I hope everyone here is using synthetic oil.

 

[RustyRatRod]

Try looking up how pressure affects the boiling point of a liquid in a physics book. That is why the cooling system is pressurized; it raises the boiling point to approximately 265 degrees Farenheit.

All of my Mopars have run in the 195 to 210 degree area. I have always used either 195 or 180 degree thermostats, and I really suggest you do the following:

1) Get a 26" radiator (your loosing too much cooling area with the 22")
2) Get rid of the electric fan
3) Make sure the fan clutch works, or replace with a Mopar HD unit
4) Make sure the fan shroud is correct for you application, and that the fan fits in it correctly
5) Install a 195 degree thermostat as designed by Chrysler Engineering

Your temps are not horrible, but these fixes should bring it down a little. If you are not using synthetic oil, you might think about it. I lost about 10 degrees when I changed over from regular oil.

All THIS ^^^^^^^^

 

[67 B-body]

I'm not so sure about this "boiling out contaminates" business,,,, regarding engine oil???
I would also like to point out that your mechanical fan isn't doing much once you hit 35mph give or take a few.... A shroud is designed to work in conjunction with the FAN,,,, not highway speed driving... You can easily deduce this by observing its location in regards to the radiator. It is located on the opposite side of the direction of airflow,,,, It's purpose is to provide an equal displacement of air across the surface of the radiator when relying on the fans air draw, and also prevent air from entering the fans blades from any point other than its face "front side" and preventing cavitation at the tips. It's basically a ducted fan that opens up into a closed plenum evenly covering the surface of the radiator. We do the same thing in aviation to provide the best case scenario in propeller efficiency by providing a duct around the blade....
I still contend that the 200+ temps are on the high side of normal operating temps on our old engines.... the factory must have thought so too,,,,, the factory gauge would be leaning heavy to the right at those 210* temps were speaking of. If you run them hot and get away with it,,, great..... I'm glad to see another Mopar going down the road regardless of opinions.....

 

[64Belvedere]

The electric has definitely helped some. I think I'll be pulling the rad and having it flushed and rodded then add a mix of 50% coolant/50% water and water wetter. If that doesn't improve anything I'll be looking at an aftermarket aluminum setup. The fan is a Mopar 7 Blade and is approx 3/4 to an inch from it. (That's a guess without looking at it as I'm at the office.)

 

[RustyRatRod]

I'm not so sure about this "boiling out contaminates" business,,,, regarding engine oil???.......

All you have to do is pull the valve cover breather off something that's not driven much. You'll see milky lookin crud on it. That's moisture contamination. You'll never get it out unless the oil temp goes past about 230* for an extended period. That's where the old saying "short trips are bad for cars" comes from. ...and it's true, 100%. That moisture and those contaminants will eventually turn into sludge. Since the oil temperature is directly linked with how hot the coolant temperature is, you can bet the coolant temp will have an effect. Just food for thought.

 

[67 B-body]

All you have to do is pull the valve cover breather off something that's not driven much. You'll see milky lookin crud on it. That's moisture contamination. You'll never get it out unless the oil temp goes past about 230* for an extended period. That's where the old saying "short trips are bad for cars" comes from. ...and it's true, 100%. That moisture and those contaminants will eventually turn into sludge. Since the oil temperature is directly linked with how hot the coolant temperature is, you can bet the coolant temp will have an effect. Just food for thought.

Yaa,,, I've certainly seen my share of milky sludgy oils,,,,, just never because of a lack in engine operating temperatures.... The lack of maintenance has been the direct cause of severe oil contamination in all cases I've dealt with.:eusa_think:

 

[RustyRatRod]

Yaa,,, I've certainly seen my share of milky sludgy oils,,,,, just never because of a lack in engine operating temperatures.... The lack of maintenance has been the direct cause of severe oil contamination in all cases I've dealt with.:eusa_think:

Absolutely true. But if the oil never gets hot enough, the contamination will never be boiled off....and remember, most contaminants you cannot see.

 

[Bad Sport]

Milky oil is a direct result of not getting to operating temperature and maintaining it for a long enough distance. Most commonly found in "short trip" engines.


Condensation in the Oil System

This is more common than you might think. A weather change from warm, moist weather to cold weather or repeated frost (condensation) on the vehicle and frequent high dew points can create moisture to form in the crankcase. This can appear as condensation in the oil system and under the valve covers. Most of the time vehicles are driven long and far enough so that this condensation is burned off thanks to the heat of the engine. However a vehicle that is not driven very far and does not reach full running temperature for very long may not purge out the moisture. Vehicles that are not driven frequently and sit outside can also acquire moisture in the oil system. When these vehicles are driven, the engine generates some heat during the short drive, then cools. The trapped moisture condensates on the coolest part of the engine, the valve cover and oil cap. Repeated short trips will leave behind more and more moisture on these cooler parts. You then open the cap and discover this milky white buildup of creamy mocha colored slim.

 

[RustyRatRod]

Good job my yankee friend. :headbang::blob1:

I knew you were good for somethin. lol

 

[ArtH]

I think fan shrouds do help although cars went for years without them. As mentioned, it is definitely a safety device, I came real close to losing some fingers years ago helping a friend out with is car and skinned my knuckles with the fan. Scared the heck out of me. However, I will say that GM F bodies and others did have a small air dam across the front under the fan area that I was told by a couple technicians did help cool the engine. The purpose of it was to create a differential in air pressure (please don't ask me to explain that) and that made for better air flow through the A/C and radiator. Those cars didn't appear to have much open grill area as does my Cordoba and other older cars and I'm guessing that's the reason. The problem with those cars was it was easy to knock those things off when pulling off the road into a parking lot or drive that had a steep ramp or speed bumps could ding them too. A lot of guys just pulled the sagging thing off and temps began to rise. The shrouds do create a wind tunnel effect to assist in drawing in air.

My thoughts on engine t'stats. Some people remove them thinking that's going to help cool the engine, not so. The coolant now circulates too fast not allowing the hot coolant to transfer the heat from the coolant to the atmosphere. I have never found going to a lower rated t'stat as a way to lower coolant temps. My car was designed to run with a 195 degree stat and it does fine. Some say this is for emissions and I'm sure it is. That's not necessarily a bad thing. Chrysler engines are rugged, 210 degrees shouldn't cause them to fail.

One last thing and I'll shut up for awhile. Anytime you get away from OEM specs, it has ramifications and consequences on other areas of the car. No big revelation here, you all know that. But, a dramatic increase in HP and torque will have consequences on the transmission and other parts of the drive train unless they too are improved to stand up to the additional forces being exerted on them. Same goes for heat. Our engines work on heat. Raise compression or cylinder pressure there's going to be more heat. That's what makes the piston move faster; rapidly expanding hot (super hot?) gases. So, you may have to improved the cooling system. Bigger radiator etc. If your engine is at factory specs, then all other items should be too and work properly unless there is a problem somewhere else in the system. I grew up when most of these cars were new and I don't recall over heating being a common problem.

Sorry for the windbag post.

 

[turbo36]

Do you have a "high flow" water pump? I was running a high flow pump but switched back to stock, it dropped my temps 5-10 degrees.

 

[HT413]

Or better yet, is the electric fan motor sitting directly in front of the rad dead center and the clutch is on the the other side in line with the electric motor. If so, the motor is blocking airflow to the clutch. that coiled piece of metal needs to have air coming off the rad to react to.

That was probably the best explainanation I've heard regarding the interferance of electric 'helper' fans. Thanks.

 

[HT413]

Not that i'm looking to get into the fray here, but it seems to me that the electeic fan is just a bandaid that's masking a broader problem. Like some of the guys have already said, chrysler engineers knew more about how cool these motors than we do, and it sounds like the factory stuff isnt doing the job for ya, so rather than assuming they were wrong, your money will be best spent trying to troubleshoot which part of the factory setup isnt doing the job. Flushing and rodding the rad is a great idea. Is it possible to flow test the water pump? Is it possible to test that clutch? These things can be answered by others here. How about flushing the block and looking for scale? Oxides of all sorts kill heat transfer and no alum water pump/pusher fan/alum rad will overcome that.

 

[khryslerkid]

Do you have a "high flow" water pump? I was running a high flow pump but switched back to stock, it dropped my temps 5-10 degrees.

This is another good point! If coolant runs thru the radiator to fast, it doesn't get a chance to get rid of the heat either.
Several times someone would bring me a car that was overheating just to find out that the thermostat had been removed. That will let the coolant flow too fast in some cases causing overheating.
There are a lot of causes, some small, that will effect temps. And not all cars, trucks, and engines act the same.
This thread will probably go on for a while yet!

 

[Hemi Rebel]

I knew it was just a matter of time before the myth about an engine overheating without a thermostat would show up. This is false.

 

[RustyRatRod]

I knew it was just a matter of time before the myth about an engine overheating without a thermostat would show up. This is false.

That's right, because as I and a couple of others have (you included) already pointed out, the thermostat ain't gotta thing to do with how HOT an engines gets. All it controls is the minimum operating temperature and nothing more. It really doesn't matter how much you dangle the truth in front of some people, or even what kinda seasoning you put on it, there are some who will not bite no matter what.

 

[64Belvedere]

I have a buddy here with a Nova SS and he is having a heating problem as well. I asked him what he had done to it and he mentioned that he had taken the the thermostat out (cause that's what dad does with his Camaro Drag Car) to improve flow. My response to that was The factory engineers spent hours and millions to design a car with a thermostat why would anyone change that and think it would improve the situation. I am of the opinion that in most cases the engineers are smarter than I am and they set things up for a reason. Anyhow, I am going to have the rad cleaned and rodded and hopefully that will help. Not sure about the water pump that will be the last thing I check if there is no improvement after the rad is cleaned.

 

[RustyRatRod]

Usually, the factory got it right. It's a good bit harder to improve upon the factory design than most people think. Nine times out of ten, a larger capacity radiator alone will do the job. Of course, that's considering everything else is present and accounted for.