How hot is too hot

[haysonj]

We are having 100 degree heat in California and I drove to LA yesterday. In heavy stop and go traffic my temp went up to 220 and stayed there. I have electric fans and a high flow water pump with a 195 degree thermostat. Also have a new aluminum radiator. Is 220 too hot for an extended period of time.

[chrislehr]

water boils at 212. Antifreeze, 370.

Assuming a 50/50 mix, you should be fine.

Personally, I get nervous when my gauge approaches 200, though

[pumpkin]

Depends on a lot of factors. Compression ratio, how tight the engine is, and how hard you drive it. One year on holidays we went from LA to Vagas in 120 degree heat, with the motor home flat towing the Blazer. The temp gauge was reading 250-260 degrees all the way. I run synthetic oil the the M/H because it can get very hot. On our trip there were vehicles pulled over about every 1/4 mile cugging coolant all over the place. Even though the temp was a bunch higher than I would like, if I had of stopped, I would have probably been one of those stranded people, in the middle of the desert with my coolant boiling out of the rad. I worried about it the whole way, set the cruise control and let the engine plugg along. This trip had no ill effects on the engine, its been 4 years and 10,000 moles since. Before this experiance I have always had 240 deg. as my shut down temp, and by shut down I don't meen turn the engine off, but do wat it takes to cool it off.

[WorkinLonghorn]

220 is nothing.If you have a good anti-freeze mix and a good cap and good oil you should be good to 265.

[haysonj]

Originally Posted by chrislehr

water boils at 212. Antifreeze, 370.

Assuming a 50/50 mix, you should be fine.

Personally, I get nervous when my gauge approaches 200, though

Me too I spent most of the trip in the slow lanes thinking I might have to pull over but once the traffic started moving it dropped back down to 195

[imholte]

Originally Posted by pumpkin

Before this experiance I have always had 240 deg. as my shut down temp, and by shut down I don't meen turn the engine off, but do wat it takes to cool it off.

I think this is something that not too many people think about. If you rig is getting hot dont turn it off.

[WorkinLonghorn]

Oh yeah,that's the worst thing you can do. If the coolant stops circulating it really starts to boil and will totally overwhelm the system.
The right thing to do is pull over and run in neutral a very high idle until it cools down.I've done it one or twice and it works.

[Wrenchbender Ret]

As long as the coolant level stays full you won't damage the engine. When the coolant level gets low so it's not circulating & not touching the upper parts of the engine is when serious damage results.

[Stocker]

Originally Posted by chrislehr

water boils at 212. Antifreeze, 370.

Assuming a 50/50 mix, you should be fine.

Sounds a bit high, did you mean 270? At any rate, especially with a pressurized system and 50/50 mix, 220 is no problem.


Edit: Another good reason for a sealed system: there is more coolant (and no air), so more heat can be dissipated.

[berencam]

265 yow. i get worried when i see it go over 170.

[chrislehr]

Originally Posted by Stocker

Sounds a bit high, did you mean 270? At any rate, especially with a pressurized system and 50/50 mix, 220 is no problem.


Edit: Another good reason for a sealed system: there is more coolant (and no air), so more heat can be dissipated.

I pulled that from wikipedia
http://en.wikipedia.org/wiki/Antifreeze

Its under new developments though, so may not be 100% accurate.

Shooting from the hip here.

[Shyguy]

I have a '92 GMC K-3500 duallie that runs warm when pulling a our 5th wheel travel trailer, by warm I mean 230-250 at times. I have put about 40,000 pulling the trailer and so far have not had any ill affects to the engine.

It has a factory auxiliary fan that is set to come on at 225 degrees.

I did have the transmission (4L80E) rebuilt at about 50,000 miles though. I had the guy do a heavy duty rebuild, put in a new torque converter and synthetic fluid. In 1992 they put in some bad shims/spacers and they gave me an extended warranty, but as my luck normally runs the warranty was up before the transmisson went bad.

I guess what I am saying is the temperature your truck got up to should not be a problem.

Danny

[Stocker]

Just found this image taken from a Prestone jug... dunno if they already accounted for a pressurized system, so the temps *may* be a bit higher.



And this thanks, chrislehr:

In the 1980s inventor Jack Evans discovered the advantages of using a waterless coolant. His final formulation is a mixture of ethylene glycol and propylene glycol. This coolant has a high boiling point of 370 °F and is not corrosive, solving many of water's problems including freezing.

Most commercial antifreeze formulations include corrosion inhibiting compounds, and a colored dye (commonly a green, red or blue fluorescent) to aid in identification. A 1:1 dilution with water is usually used, resulting in a freezing point of approximately −40 °F (−40 °C). In warmer areas weaker dilutions are used.

http://en.wikipedia.org/wiki/Antifreeze_(coolant )

[70clone]

couldnt you put like a 160 or 180 degree thermostat wouldnt that help you out

[WorkinLonghorn]

All the thermostat does is set the Minimum temperature,and has no bearing on cooling efficiency.

[Zonaman]

I think one problem with higher temps- close to boiling is steam pockets that can form in hot spots. There's this stuff called Water Wetter that's supposed to help with that. I used it on an old Mercedes I owned and it did seem to run a bit cooler. I've never heard of this being a problem on a small block GM that's more or less stock though.

[Stocker]

Yeah, I run a stock (I think) 195 and don't overheat... plus, my heater works in the winter and I don't have to change thermostats with the seasons.

[leddzepp]

Originally Posted by Zonaman

I think one problem with higher temps- close to boiling is steam pockets that can form in hot spots. There's this stuff called Water Wetter that's supposed to help with that. I used it on an old Mercedes I owned and it did seem to run a bit cooler. I've never heard of this being a problem on a small block GM that's more or less stock though.

I have used water wetter myself and have had good results as well.

[LONGHAIR]

All the thermostat does is set the Minimum temperature,and has no bearing on cooling efficiency

That is 100% right. It allows the coolant into the radiator earlier during warm-up and if the system is not efficient enough to get rid of enough heat, the coolant just flows constantly trying. Once opened, the temperature rating of the 'stat really doesn't matter....unless the system can push coolant at a low enough temp to allow it to begin to close again. It is really just ensuring that coolant doesn't get to the radiator until it reaches that temp.

As far as the 220.........no sweat. As uncomfortable as it may be, turning the heater on ads another "radiator" and fan into the system. If is is bugging you that bad, turn the heat and fan to "High"

[Stocker]

Originally Posted by LONGHAIR

As uncomfortable as it may be, turning the heater on ads another "radiator" and fan into the system. If is is bugging you that bad, turn the heat and fan to "High"

And that is also 100% correct! Back in '69, I was living in Barstow, CA and drove the '65 Corvette up to Big Bear Lake on a very hot weekend. With a 327/365, it didn't cool too well anyway and it started to overheat. I turned the vents to 'defrost' to deflect as much heat as possible from me (no A/C available with the 365 hp engine), and turned the heat all the way up and the fan on 'high'. The engine was comfortable even if I was not!

[HoupPhotography]

Originally Posted by WorkinLonghorn

All the thermostat does is set the Minimum temperature,and has no bearing on cooling efficiency.

Then why use one at all?

[truckdude239]

so that your truck can reach peak opertating temps faster for better fuel mileage and heat come winter time

[berencam]

Originally Posted by HoupPhotography

Then why use one at all?

Take it out and see how long it takes to get hot air from your heater. The thermostat takes and cuts off the radiator below whatever temp its rated for, so you can get hot air very fast. Once your coolant heats up, it allows it to go to the radiator to cool down.

[shortbed70]

I run water wetter in mine now but when I didn't last year with a 3 speed and it got to 220 going down the highway and as far as turning it off when its hot don't do it you never see a hot dirt car go into the pits and if it hot just shut it down. I run the water wetter now so I'll see what happens this summer.

[Stocker]

Originally Posted by HoupPhotography

Then why use one at all?

Also (though I have never tried this, just something I read somewhere), running with no thermostat can let the coolant circulate too fast -- that is, it isn't in the radiator long enough to cool down, and returns to the engine... continually getting hotter. As a result, you might actually run hotter with no thermostat than with one. True? I dunno, maybe someone here has had it happen...