how hot is too hot?

[NMEMJCM]

Hello. I have a 347 (well, its a standard bore engine so I guess its somthing like a 342) I have a 180 thermostat, but the car seems to want to run at 190-195 ish all the time (the thermostat is probably alittle late on opening, and is fairly new.....at night its around 187, during the day it is about 195 ish). Is this to hot? How hot can I get before I should get worried? 220? I have a Griffen radiator with their electric fan set up and aluminum heads.

 

[iskwezm]

My car used and has run as hot as 230*. Now its down to a constant 170-180. Yours sounds ok, i wouldnt worry about it, but 220 would be the highest i would let it get even though that still is where a new car runs today.

 

[robbz28]

My car used and has run as hot as 230*. Now its down to a constant 170-180. Yours sounds ok, i wouldnt worry about it, but 220 would be the highest i would let it get even though that still is where a new car runs today.

There is nothing wrong with 200....like mentioned, 220 would be my limit. Cars are made to run hotter today because it burns fuel more efficiently, all about mpg's.

 

[2+2GT]

Ford considered 220° to be the overheat, point, that's where the DVCV opens to increase cooling.

 

[palerider94]

Ihave a 347 roller also. Runs 190 all times.

 

[NMEMJCM]

So... there is only a 30 degree difference between normal 190 degree running and overheating at 220 degrees? Is that right? The car ran for about 10 minutes with out the fan on and I sar it was at 240 degrees. I pulled over, and let it cool. I lost no fluid as it went into the overflow tank and got sucked back in. Everything looks fine. Do I need to change fluid now or somthing???, seems the car runs alittle hotter since that event.

 

[rbohm]

215 is the highest temp i would run and feel reasonably good about. 220 is ok as long as it isnt fluctuating higher than before coming back down. since the early 80s, engines have been set up to run at about 210 degrees for better fuel economy and better wear characteristics.

 

[blown65]

Same as said, 220 is the highest Ill go. Even though mine usually never sees above 180

 

[Couped Up]

Couple of questions....

(1) Are you running straight coolant?

(2) Have you considered installing a cooler t-stat?

 

[robbz28]

To add to Couped UP's questions...
3. do you have a clutch and shroud on your radiator?
4. is it a regular old 2 row copper radiator?
5. do you have an electric fan?

 

[NMEMJCM]

Thanks for everyone's help, My cooling set up is a Griffin aluminum radiator with an electric fan (the brand of the fan is Spall), there is an aluminum cover that go's around the fan and covers the radiator that the fan bolts to (acting like a shroud)....the entire setup is from Griffin. I have a 180* thermostat and am running 50/50 mixed with a bottle of watter wetter additive. I could put in a 160* thermostat, but I don't want to pull the coolant from the radiator too quickly. I read somewhere that if you have a 180 thermostat it is normal to run around 190. I don't know if this is true or not. After you overheat is it necessary to change the coolant? Thanks for everyone's help.

 

[robbz28]

With that setup and still ran hot....might want to make sure your thermostat is opening up all the way. I have my electric fan set up on a thermostat activated switch that cuts the fan on at 200 and off at 180 (or when my AC is engaged) I have a 2 row aluminum (1" rows) with a 16" puller fan and no thermostat (I know I need to put one in, but I ruined a good motor thanks to that part, and I had a brand new one stick on me in this car already)
As far as replacing the coolant, I have never heard of that, I would suggest testing the coolant and if your balls still float then I wouldnt worry about it.

 

[pabear89]

A 180* stat will run at approx 187* in its fully open position.

I run a 180 in my 351CJ and it stays right at 185 while running down the road.
Sitting in traffic it will climb to about 192* but drops back down after getting in motion.
This is what you should see when the cooling system is working properly.

 

[Hack]

As long as you aren't boiling coolant you are fine. The actual cylinder temperatures are much higher than 200-250 or whatever. The engine can stand anything as long as you don't boil the coolant out of it. When the coolant starts boiling then you have no protection and the temperatures will sky rocket. That's when you can damage parts.

Bottom line is - you are getting temperatures of 190-195 - nothing is wrong and you have nothing to worry about.

 

[NMEMJCM]

Thanks guys! I guess I was always used to seeing 180* out of more mild engines, thought that would be the norm. Ill rest easy now... Thanks!

 

[iskwezm]

also check the guage is reading correctly. I have a autometer guage that read about 182* after about 25 minutes in my garage, my laptop said it was actually at 162*. I thought for YEARS my car ran hot and the whole time it was the guage that is about 20* off.I replaced fans,waterpumps,radiators etc.

 

[robbz28]

As long as you aren't boiling coolant you are fine. The actual cylinder temperatures are much higher than 200-250 or whatever. The engine can stand anything as long as you don't boil the coolant out of it. When the coolant starts boiling then you have no protection and the temperatures will sky rocket. That's when you can damage parts.

Bottom line is - you are getting temperatures of 190-195 - nothing is wrong and you have nothing to worry about.

The only thing I would advise about this is the Radiator Cap pressure....you can keep a hot car from boiling over by increasing the cap pressure, thus lowering the boiling point of the water. I know they make some rediculously high caps 20lb and up...but then you can bust a seam on a heater core quick, sounds like he has a new cooling system so a 14-16 lb cap is probably ok, but if you have an old rad or heater core id keep the cap around 7 lb, just a tidbit for yas...

 

[brianj5600]

If you are worried about temps in April, how do you think it will be in August? I want mine to be able to run on the t-stat, which it does, even with a pusher fan and way more under the hood heat than most. My car did run a little warm on the interstate with the e-fan off because of the large shroud, 95 GT fan. Turning the fan on let it run at 180* which is what the t-stat is.