How hot is too hot?

[64Belvedere]

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.

 

[tpodwdog]

normal operating temp is 210....i wouldnt get too excited about 225.....is the engine newly rebuilt? if it is,,,itll wear in and loosen up !

a common misconception about thermostats is this..........." i got a 160 t-stat and it runs well above that !"

160 is where the t-stat begins to open and lets coolant circulate to the radiator.......NOT what it will keep your engine at....i recommend a 180 or a 195 t-stat.

i would lose the pusher fan....all its doing is blocking air flow....trust me on this !

 

[terzmo]

210 is on the verge ofoverheating...225 is a no no. The young guns think 220 is fine because of new engine technology. If You run a stock gauge and a digital..You will see when the stock gauge just gets to the high end of the hot range..that's 210 and on the verge of overheating..old iron motors with old iron heads like 180 to 190 for aptimun temp for performance....mopars don't run as well at high temps vs cool...Now...from past experience...some say I'm full of ...beans..crap...whatever...but with over 45 years driving experience and working on mopars...this is My advice....cool ...is cool...it's Your car...run it as You like but those temps are too high as far as I'm concerned...best of luck

 

[67 B-body]

210 is on the verge ofoverheating...225 is a no no. The young guns think 220 is fine because of new engine technology. If You run a stock gauge and a digital..You will see when the stock gauge just gets to the high end of the hot range..that's 210 and on the verge of overheating..old iron motors with old iron heads like 180 to 190 for aptimun temp for performance....mopars don't run as well at high temps vs cool...Now...from past experience...some say I'm full of ...beans..crap...whatever...but with over 45 years driving experience and working on mopars...this is My advice....cool ...is cool...it's Your car...run it as You like but those temps are too high as far as I'm concerned...best of luck

I have to agree...... The average temps went up on modern engines to aid in combustion and reduced emissions, but they are not the same as our older Mopar engines.
I have always had the opinion that 180 was prime temperature for my big block Mopars when getting the most out of the engine.
I'm not suggesting that damage will occur at 200 while cruising down the highway, but it is most certainly on the high end of my liking's.
I think our older engines with aluminum heads might get the temp gauge up a little higher because the heads transfer heat very quickly.... They are actually very non-efficient thermally because of the dense aluminum construction.
I believe that the fast wick effect of heat gets put right into the cooling jackets instead of dispersing and soaking through the entire head and block iron casting....
Maybe,,, Maybe not,,,, but it seems to be the case.:icon_neutral:

 

[Meep-Meep]

I suppose the right answer is too hot is at the point of oil breakdown. When the oil stops doing its job bad things happen. 225 coolant temp is pretty hot, and I would take steps to cool it down to 180 or so, but it's not necessarily the end of your engine. As long as you have coolant circulating you can get away with it. On average I'd like to see under 200. You want to talk hot? How about air cooled VW's and Porsche 911's? I had both. The 911 had oil temps up to 220 on a hot day buzzing down the hwy at 4000 RPM for 5 hrs.

 

[ChgrSteve67]

200 is a bit high

Why did you install the pusher fan?
What does your temps do if you take it out?

I'm wondering if the electric fan isn't blocking air flow.

Can we see a picture of your setup?

 

[RustyRatRod]

Most all modern engines do not turn the electric fans on until 230*. They have aluminum heads and blocks in some cases. Remember the coolant is under pressure. That raises the boiling point usually to the 260* area. Also, add in the fact that you're running a coolant mix too. That raises the boiling point even further. I'm not saying it's good to let your motor run up to 260*, but it's probably not truly overheating until around 240 or so.

As was mentioned, the thermostat has ZERO to do with how hot an engine gets. What it does control is the minimum operating temperature. If you have a 160* thermostat, that means when it opens....it STAYS open. That's not good. The thermostat should cycle open and closed.

Best thing you can do is mirror newer cars. Close off the sections behind the front valance between the rear of the front valance and the K frame. This diverts more air through the radiator rather than under the valance and into the engine bay past the bottom of the radiator. Close off any extra holes in the radiator support. Any air that can be diverted through the radiator instead of around it will help. It also helps to make sure you have a proper fan and shroud. The fan should extend only halfway into the shroud.

 

[RustyRatRod]

200 is a bit high...

No, it's not. 200* is just fine. 220* is not overheating. As long as the engine cools off when on the road, 230* on a hot day idling in traffic will not hurt a thing.

In order for the oil temperature to get hot enough to boil moisture off, it has to reach about 230* Generally, optimum coolant temperature is 10* under the oil temperature. If you have an engine that never sees 200*, you're never boiling the contaminants out of the engine oil. It will build up moisture and begin to break down MUCH quicker by not reaching optimum operating temperature.

 

[khryslerkid]

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!

 

[copper67440]

No, it's not. 200* is just fine. 220* is not overheating. As long as the engine cools off when on the road, 230* on a hot day idling in traffic will not hurt a thing.

In order for the oil temperature to get hot enough to boil moisture off, it has to reach about 230* Generally, optimum coolant temperature is 10* under the oil temperature. If you have an engine that never sees 200*, you're never boiling the contaminants out of the engine oil. It will build up moisture and begin to break down MUCH quicker by not reaching optimum operating temperature.

I agree. I was on Woodward ideling in traffic with a *180 degree thermostat and my mechanical guage would go up to 210-220. never puked. I was keeping my eye on it tho.

 

[cordoba-440-man]

i had this

when i redid my 440 i ran it for 3 days with no hood it ran hot around 225 and some times hotter on short trips then i added a 160 thermostat that did not do a thing so after about 250 miles running 200 on the highways 225 to 235 on town roads and i could not get stuck at a light in town or go up a big hill or i would haft to pull over tune it off and Wait because it would start to over heat so this is what was causing this the guy i got my car off of put a new rad in it from summit it was smaller then the stock 400 rad and had no shroud and it had a flex fan this was all junk i looked forever for the factory shroud and i put a 7 blade fan on and a aluminum rad and the orange coolant and she will run 165 to 175 in town on a hot day in the 90s this 440 is my 1ST big block mopar so you veteran mopar big block guys think this is to cool ?

 

[rev.ronnie]

I would put a bottle of Redline Water Wetter in the cooling system with as small a percentage of anti freeze as you can. It will come down 20 degrees. Antifreeze is a horrible coolant. It does not dissipate heat like water does. Water wetter has corrosion inhibitors and seal lube in it as well. I run it in everything.

Here's an example from personal experience:
-----------------------------------------------------
My dually runs 220 degrees on 50/50 antifreeze and water...and gets worse than 6 mpg hauling the race trailer.(19,000 lbs gross wt.). Now, with a flush and almost no antifreeze, and two bottles of water wetter, it runs around 190 and gets 7.5 mpg or better. I suspect that when it is hot, the computer dumps fuel like mad to compensate. It makes no power running at 220 as well.

I run it in my Charger as well, with 11:1 compression. With a 160 stat, she never sees 180

 

[64Belvedere]

I put the electric fan on because the temps were getting to 240 on cruises thru town. The pusher has brought it down some, I do like the water wetter idea, I run it in my fathers 64 Olds 98 convert for parade use and find it works great. On this car, the rad seals up the entire opening in the rad support and there is a filler panel at the bottom behind the bumper as well. There is definitely more airfow with the pusher fan on, and it has slowed down how fast the car gets hot. I'm planning to put a 3 or 4 core aluminum rad in with a shroud over the winter. It is not a fresh motor. I drove the car home from Massachusetts 4 years ago with it and it stayed around 190 to 200 on the highway on the cool evenings. I notice it's a lot hotter under the hood since I took the headers off and put manifolds back on.

 

[terzmo]

running an engine overheated burns contaminents out of the ol and that i good ????lol
I'll run My mopar, as designed at cool temps and change the oil regularly..as designed. Nothing is being done to change 60's technology to the new millinium technology. Old motors have gears,seals,couple pumps....no electronics like todays junk. If 220 were the operating temp, the in dash gauge would be centered instead of being pegged.

 

[RustyRatRod]

running an engine overheated burns contaminents out of the ol and that i good ????lol.

Nobody said anything about "running an engine overheated." If you want to operate your car based on old wives tales and hearsay, it's your car. It was not "designed" as you say to run cool. All automotive engines are designed to run somewhere in the 200* range. Coolant and oil temperature play key roles in engine life and the oil must reach proper operating temperature to boil moisture and contaminants out. The temperatures of the coolant and oil are linked to one another. You've been given correct information. Not some BS you grabbed off the internet, or overheard someone giving misinformation to someone else. Engines are not designed to run at 180* and under. Premature wear of cylinders and rings can result and excessive oil usage will be the outcome. The internet is your friend. You should use it for something other than finding pictures of boobs and old wives tales about engine temperatures. What I have told you is correct. I cannot help that you are too dense to comprehend it.

 

[ArtH]

I've looked through several service manuals and I can't recall ever seeing a specific temperature that is stated to be over heating. The factory manual for 1977 Chryslers indicates some cars come with a valve that opens allowing additional vacuum advance in order to increase engine idling speed when the engine temp reaches 225 degrees. The additional idle rpm increases coolant flow and draws more air through the radiator. The same TIC valve is used on my 77 Buick. I've never been concerned about engine temps reaching 200 to 210 degrees in any car I've owned. However, if you are moving at higher speed without much of a load on the engine (65 mph on the interstate) and the needle keeps climbing, I'd be looking for that service station the Viagra guy pulls into with his old Camaro pdq.

 

[RustyRatRod]

Exactly. Because if one keeps the temp climbing at highway speed with tons of airflow, something is wrong.

 

[tpodwdog]

thanx for backing me up Rat Rod and Art h.....i didnt think i was crazy. 160 is WAY too cool....250 is wayyyyy too hot...195- 210 IS PERFECT OPERATING TEMP. im not sure where these guys are getting information....but im not going to argue the point being that i know better. rock on gentlemen.

if you need all those fans to keep your engine cool....then you better be looking into purchasing a new radiator....nuff said!

fan shrouds are not necessary on our mopars.....all they do is keep fingers out of the fan. did a 57 chevy have a fan shroud?.....NO.....why?..because you dont need one. these shrouds they put on our Mopars are too shallow to duct ANYTHING. you wanna see a functional fan shroud ???....go find a stock 1971 Monte Carlo... the damn thing is 2 feet long.....why is it there?.....because the engine is 3 feet away from the radiator....THATS WHY!

thanx guyz!

 

[RustyRatRod]

thanx for backing me up Rat Rod and Art h.....i didnt think i was crazy.

Naw, you ain't crazy. I think the whole "runnin cool" thing is a chebbie thing. I hear them boys braggin about how cool their stuff runs at shows sometimes. I reckon they don't know any better.

 

[Bad Sport]

I agree. I was on Woodward idling in traffic with a *180 degree thermostat and my mechanical gauge would go up to 210-220. never puked. I was keeping my eye on it tho.

Howdy neighbor.