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Discussion Starter #1
I've always had the stock dummy temp gauge, so I don't know the actual temp number my engine is running. (New one not hooked up yet) I've been debating between a 180 or the stock 192 stat. I was wondering for you guys that run actual temp gauges with numbers does your actual engine temp going down the road or idling generally match your stats rated temp or does it normally run above it or below it, all being based on having a good cooling system. For example, If I use a 180 stat, when I'm idling or going down the road, will my actual engine temp generally be between 180-190 or would it be between 170-180?
 

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I have my gauge tapped into the thermo housing while retaining the stock gauge.
I am running a 180 stat.
Once my enging starts to warm my gauge slowly rises with the temps. When my thermo opens my gauge reads 180 and will fluctuate according to the conditions. For instance, sitting at a light in hot weather it will rise to maybe 190 - 195. In the winter while driving I have seen it drop to around 170 -175 and no lower.
I am running a stock mechanical fan assy, stock H2O pump with a Cobra H2O pulley and a renegade lower.
I have zero cooling issues.
HTH
 

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Mine runs the t'stat temp when there's enough air flowing over the radiator to cool it to that level. When there's not, and the electric fans are moving the air, it runs the temp that the fans are set to control to - 187F. In the winter under cruise I'll see 175F; in the summer in traffic I'll see 190F with the fans on. This is with a 180F t'stat.
 

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One of the things i've noticed over the years is... your gauge readings will be different depending on where your sender is located. closer to the thermostat, the better..
 

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Discussion Starter #6
Thanks guys! From what you guys are saying it appears that the engine geberally runs over the stat temp unless it is winter or something, so I'll go ahead and do the 180 instead of the 192. When I switched from my 94 computer to a fox A9L, it came with a fan controller, so I can set the temps that the low and high fan comes on at. Thanks Again!
 

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A thermostat's rated temperature is where it begins to open +/- 2*, it should be fully open by the rated temp + 20*. So if your cooling system is properly sized and operating correctly the temp should hang around somewhere between the rated temp and +20*.
 

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....and I always check mine in a pot of coolant on the stove top (do this when your wife is NOT home) with a thermometer. You'd be amazed at how many don't start opening until 4, 5, 6F AFTER the set temp. Also Aaron, getting a variable current/speed controller is a MUCH better set up than a relay that has the fan either all on or all off. They only turn the fan as fast as is needed to achieve the desired set point. So they hold MUCH more constant engine coolant temps. Be sure to set the fan 'on' temp at least 5F-7F higher than the t'stat temp or you're likely to have it running all the time.
 

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Discussion Starter #9
....and I always check mine in a pot of coolant on the stove top (do this when your wife is NOT home) with a thermometer. You'd be amazed at how many don't start opening until 4, 5, 6F AFTER the set temp. Also Aaron, getting a variable current/speed controller is a MUCH better set up than a relay that has the fan either all on or all off. They only turn the fan as fast as is needed to achieve the desired set point. So they hold MUCH more constant engine coolant temps. Be sure to set the fan 'on' temp at least 5F-7F higher than the t'stat temp or you're likely to have it running all the time.
Michael, I've seen those controllers you mentioned and they really are awesome. Right now I am just using the factory low/high electric fan and the PIH controller just has the temps to set, but nothing variable about it just on/off. Cooking antifreeze on the stove might get me in trouble. I've done that before with just plain water,but never antifreeze. How can you see it in the coolant to know it's opening. Is coolant that tranparent. Would the temp be different in coolant rather than just water?
 

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Intresting that they don't fully open untill 20 after their rating. My car usually runs at 190ish. I have a 180
 

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I have a 180*, too, and it generally sits at about 190* so I guess enough coolant flow is occurring when the stat is only partially open.

To know when the stat starts to open in the stove-top check you should suspend it by a piece of thread through the valve. When it starts to open it will drop off of the thread.
 

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Not sure what is in my 87 i jsut bought like a month ago it always runs 130 on the stock gauge i know it has a bigger aluminum rad and e fan any thoughts?
 

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My actual water temp (measured with a good Fluke meter) runs very close to the rated thermostat temp. I was impressed.
My stock water temp gage indicates almost full scale, but I don't worry any more since I know the actual temp is fine and the gage is a little high.
 

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Discussion Starter #16
Sounds to me like the 180 stat is just right. Hot enough to keep the computer etc happy and prevent engine wear, but not be crazy hot like the stockers. I saw a graph one time by speed-pro I think, and it showed cylinder wall wear at different engine temps and wear was really low at higher temps, but whe it got down to 160 or so, cylinder wear went up big time and kept getting worse the cooler it went. 180-200 wasn't bad though, but the 200 was actually better as far as wear goes.
 

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I used a NAPA in mine - my recollection is they had 2 -- one was about $3 and the other about $9 - get the more expensive one. You can easily see the t'stat in coolant - remember, you only have enough in the pan to cover the t'stat. Antifreeze elevates the boiling point -- I always test operation in the same fluid it will actually be operating in. Think about it. Mine is fully open within 4F degrees of 180F. I suspect the cheaper ones have a wider range.

With my set up and an oil cooler with fan also operated off the variable controller, winter or summer, traffic or highway, coolant temps stay in the 175F-190F range, and oil temps stay in the 200F-230F range.
 

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Keep in mind, if you use on/off controllers, set your off temp at least 10F above t'stat so it cycles, and have 10-15F swing between off/on, and use a 180F t'stat that's fully open at 185F, you will see 205F-210F BEFORE the fan comes on. You can run much tighter temp controls with a variable controller.
 

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With the SHO fan on the '87, and a 180 T-stat, the car would run dead-on 180 on the highway, and then, in town, the fan came on at 187, drag it down to 182 then kick off.......
 
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