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coolant too hot, water wetter time?

supersize75k5

supersize75k5

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The temp gauge on the buggy has been out for a while, I decided to throw one on so I can actually see where it is at,

its a mild big block, Ron Davis aluminum rad, I believe 195 t-stat and a electric fan, unsure on cfm but it came with the radiator and is built in.


according to the gauge it warmed up to around 220, then t-stat opened and it went down to 200 and stayed there, 107 degree day and all idle with some throttle input to try to see if it would raise it much.


?? water wetter time, or leave it?


I am running the correct 50/50 mix, to hot?
 
I would check the thermostat. The gauge may be off by 5 also. Get it running temp and check it in the radiator, without burning yourself.
 
Since you're in AZ and you don't see super cold temperatures you can drop your mix to 25/75 (more water than antifreeze). Water transfers heat better than antifreeze, that will probably help more than the water wetter will.
 
ktmoutfront said:
I would check the thermostat. The gauge may be off by 5 also. Get it running temp and check it in the radiator, without burning yourself.
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? are you saying leave the cap off and use a thermometer? Thats what I assume our saying anyways.

Ill have to look into the 75/25 mix too, thanks so far

I ordered a new gauge and temp sending unit, turned out the race gauges I have the warning light is set up for 225 or more:doah:
 
put a colder t-stat in it, if it's running at 200, that is right in line with the t-stat
 
200 degrees at ilde with a mild big block in AZ at idle ( and probably in your tune ) and not moving when its a 107 out . I don't see a problem .

Just make sure you have a good shroud setup ( or electric with its own shroud ) so it draws air through . Tune it right , and drop that thermostat down since you took the EFI off and went back to carb ( you did , right ? )
 
I wouldnt run the 25/75 mix. Despite water dissapating heat a little better anti freeze also has a higher boiling point which means that if you do overheat 50/50 will hold liquid state longer. With the way your system is I'd say if your going to over heat then your going to overheat due to mechanical failure somewhere not because its just too hot and the system couldnt keep up.

Now the true test of the system would be to run it in an rpm range of max torque for an extended period. This will put the maximum load on the engine and heat things up the most. Water wetter does work, theres no reason not to throw it in there as a little preventative backup. I believe when my truck wasnt handling cooling duties it would run about 7-10 degrees cooler.
 
Unless your thermostat is faulty, it doesn't matter what temp you put in there since you are over the rated temp already. Open is open, once a t-stat reaches the rated temp, it SHOULD be fully open, and no longer has ANY bearing on engine temp.

If you can't keep an engine cool with a 195*, a 160* won't make a bit of difference, except if you can somehow get the coolant that cold under low load conditions, so that it has more capacity for heat absorption under short duration higher load.
 
Stomis said:
I wouldnt run the 25/75 mix. Despite water dissapating heat a little better anti freeze also has a higher boiling point which means that if you do overheat 50/50 will hold liquid state longer.
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That is true but its not that big of a difference. 70% water 30% Ethylene Glycol (antifreeze) boils at roughly 260 degrees. 50/50 boils at ~270 degrees. IMO, 230+ is too hot anyway. If anything, boiling coolant at 250 will keep you from driving the vehicle once its that hot and destroying the motor.

All of the previous numbers are at 15 psi (the pressure produced by the water pump) and, for reference, water boils at ~250 degrees when under 15 psi of pressure.
 
Stomis said:
I wouldnt run the 25/75 mix. Despite water dissapating heat a little better anti freeze also has a higher boiling point which means that if you do overheat 50/50 will hold liquid state longer.
Click to expand...

Whoa whoa whoa! :)

Don't buy into the hype! Antifreeze doesn't add as much to the boiling point as they would like you to believe. Look closely into the manufacturers claim, and you will see that the boiling point they claim is tested at 15PSI...which actually puts straight water at around 240* boiling as I recall. What is the highest boiling point claimed with antifreeze? 260*?

No argument that if you need the higher boiling point because of climate antifreeze *might* help, but it's a judgement call as to whether the pro's outweight the cons of running less antifreeze. Better heat absorption without it, or higher boiling point with?
 
dyeager535 said:
Unless your thermostat is faulty, it doesn't matter what temp you put in there since you are over the rated temp already. Open is open, once a t-stat reaches the rated temp, it SHOULD be fully open, and no longer has ANY bearing on engine temp.

If you can't keep an engine cool with a 195*, a 160* won't make a bit of difference, except if you can somehow get the coolant that cold under low load conditions, so that it has more capacity for heat absorption under short duration higher load.
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But if the temp gauge is off by 5*, and the motor is running at 195 because the t-stat is limiting the flow if it cools down a hair, putting a 180* stat in it could potentially make it run at 180*.
 
Jason4x4 said:
But if the temp gauge is off by 5*, and the motor is running at 195 because the t-stat is limiting the flow if it cools down a hair, putting a 180* stat in it could potentially make it run at 180*.
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The temp gauge has nothing to do with any of this, accurate or not.

All thermostats do is regulate minimum temperature, they won't make an overheating engine run cooler. Supposedly there are high flow thermostats (to help with more flow) and some people in warm climates run without thermostats alltogether.

IMO the fan is probably the biggest culprit but since the problem doesn't sound too bad it can probably be fixed by messing with coolant mixtures.
 
I'm confused...a t-stat restricts flow no matter what temp rating...open is open, it's not like you reach a tipping point of no return because of the thermostat.

In a vehicle, if the engine temperature reaches 200*, any thermostat rated 200* or less, will be fully open, and ceases to be a part of the cooling equation. (except if it's complete removal would help coolant flow of course) A 195* will get hotter faster, because it is closed up to that point, however, if once it opens engine temp continues to climb, the cooling system is quite simply, inadequate, in one aspect or another. Due to conditions (engine size, load, ambient temp) it may or may not be possible to completely control engine temperature.
 
Nothing was ever said anything about overheating, he said it runs at 200* on his gauge, which could be 195*, in which case the t-stat is regulating the temp of the engine at 195*, so if he were to install a 180* stat, it is possible that it would run at 185* on the gauge.
 
Jason4x4 said:
Nothing was ever said anything about overheating, he said it runs at 200* on his gauge, which could be 195*, in which case the t-stat is regulating the temp of the engine at 195*, so if he were to install a 180* stat, it is possible that it would run at 185* on the gauge.
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Gotcha. Yeah, that could certainly be true.
 
See I never actually read into numbers on boiling point of water vs antifreeze. Its definately not as big of a difference as I would have thought.

I still dont see how a lower thermostate wont act as a bandaid if your over heating?
 
Stomis said:
See I never actually read into numbers on boiling point of water vs antifreeze. Its definately not as big of a difference as I would have thought.

I still dont see how a lower thermostat wont act as a bandaid if your over heating?
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this is how I thought of the lower t-stat swap, seems like a band aid to me.. but with a crazy pricey radiator set up.. and the mounts made and in the chassis..I can see swapping in the parts, rad or fan related.

Ill pick up the new gauge, read it..if is running hot ill try a water wetter..and from there ill try the t-stat


or should I jus swap to a 180 and a new guage?

Being in az I really want to fix this...
 
I see absolutely no problem with a 200* reading on a gauge with a 195* t-stat. That's only a 2.5% difference and I have to believe there is at least that much allowable tolerance in the manufacturing of those two parts. The general rule of thumb I learned when a manufacturer determines the allowable tolerance of a part that if you move the decimal place on the tolerance, the decimal place on the cost goes the other way (i.e. a thermostat with a 1* tolerance may cost $10, make the tolerance of the t-stat 0.1* and now it cost $100).

Also, take into account the the temperature the gauge is reading is not at the exact same place as the thermostat.

If anything is wrong at all, I would say that the t-stat may be a little sticky (slow opening) to let the temperature jump up to 220 before opening, but part or all of that could be just from where the temp. sender is located.

As already mentioned, an overheating engine will still overheat with a lower temperature t-stat. I wouldn't even consider a lower temp t-stat a bandaid, best case with a 160 vs. 195 t-stat it would give you 30 seconds, maybe a minute or two, before the engine would overheat.
 
Also, just my opinion, but DO NOT buy a Superstat, They are Garbage, every one I have ever put in has come right back out and into the trash.
 
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