160, 180, 195 T-stats

driller

driller

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OK, let's hear it. What does everyone think of the advantages and disadvantages of a lower temperatuer thermostat. Specifically the 160 degree vs. the 180 degree vs. stock @ 195 degrees.

A post of your personal experiences with a lower temp t-stat welcome. :feedback:
 
I just changed out the stock 192º in my MarkVII. I put in a Stant 180º and have noticed no difference. I might have lost the slightest in gas mileage. Same thing with a 96 Camaro. I don't see any real performance gains. The heat still seems to work quickly on the Maro, but haven't had the Mark with the 180º long enough to tell. That is a downfall to the colder thermostats: it takes longer for the heater to get warm, and it cannot get as warm.

The 160º has, on a lot of cars, caused a decent loss in fuel economy as well as confused the computer. I would not recommend them.

Another thing to remember is that the engine is still going to get warmer than the temp of the thermostat, and that the fans are still designed to come on at a stock setting for temperature, so you will most likely stay at the same temperature after driving the car for any length of time, regardless of the thermostat. My 2¢
 
John here is my two cents

Ideal block temp. for the best and most complete combustion is 200 F....

Back in the 50s and early 60s engines did not run very efficiently , and more important than efficiency , was dependibility...Keeping the engine from overheating and still providing sufficient heat in the winter was more important than maximizing hp output...160 deg.. was selected by some automotive genius as the ideal balance ...
As we approached the muscle car ERA and an all out effort to maximize hp . Another automotive genius determined that if the temp of the block was raised to 180 deg , that much closer to ideal temp , a more efficient burn would give more hp ...I think more credit should goto head design , intake design , carburetor design etc., but he was determined to make his mark , no matter how small it seemed...
Then we come into the emission era , here is where we meet all the automotive geniuses , that were sleeping in class, while while the older generation of geniuses were making great strides in maximizing engine efficiency ... It was here we threw away all desires for the best running motor , and substituted the premise , " We dont care how well it runs , as long as it burns everything we put in it..." Then the next thermostat genius said we need to raise the block temp to 200 deg for maximum burn , but under hood temps will severely hinder performance "..Then the emissions genius said "So what , we will just back it off a little".. and thats how we got to 195 deg...After they realized they couldn't keep the fuel suspended long enough in the air to reach the combustion chamber , they started using fuel injection and air from outside the engine compartment..
Now that you know the history of the thermostat , I would think that going to 180 deg would be beneficial reducing under hood temps and slightly improving air/fuel suspension...I agree with Josh going to 160 deg could have some adverse effects on mixture control ..
What do I think are the benefits of such an action ... My estimate would be about 40 or 50 RWHP gain , at a minimum expense... :why:
 
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I've done a lot of looking into this as of late. I was never convinced a 160 t-stat would give you 160 degrees operating temperature. I have a factory 195 degree in right now and can say firmly my 'normal' engine temp is 210-215. My math tells me if I have a 180 degree t-stat, my normal engine temp may be 195-200. Likewise with a 160, it may operate at 175-180.

My logic tells me it will be somewhat higher temps since it is harder to cool further and on top of that the variance will change some with ambient temperature. So I predict a 180 t-stat will run the temps at about 200-205, and likewise a 160 t-stat will give you 180-185 temps.

I hope to give the Hypertech 160 t-stat a tryout soon. Keep the responses coming though. :steering
 
After a lot of cursing I finally got the Hypertech P/N 1011 - 160 degree thermostat installed.

Sitting idling with no A/C I run a steady 180 degrees engine temperature. Idling with A/C on brings it up to 190-195.

I can't say it means anything performance wise with hard driving as it certainly has no problem getting 210-215 with the warm humid weather. But it does cool down a little lower and faster, especially with the manual over-ride relay for the cooling fan. :steering:
 
I personally have had good success running with NO T stat whatsoever.Granted it doesnt get as cold here as it does back east.
I believe Ponyfreak has had similar success with no T stat.
 
NO thermostat is just flat out stupid and you really should only get a lower temp thermosta when you have a chip or tune set for it. If you need to get one to get rid of knock then there is a problem your masking. The lower the therm temp it just opens the cooling at that tempature. With tuning a car you typically increase timing and need the increased/earlier cooling to prevent knock from the more agressive timing. Just throwing one in or not using one runs the car at a temp its not designed for and could/will be causing problems you may not immediatly be noticing.
 
IMHO the thermostat sets the lower limit of your operating temperature. I agree with the premise it should be utilized with a chip or tune and not just indiscriminately.

My whole intent was to lower the lower operating temperature limit so I may employ a cooler and more stable engine temperature strategy at the track. With the stock setup, each run down the track back to back was slightly, hotter, slower and longer. If I can get the engine temps quickly to 180'ish at the staging lanes I'll be extremely happy. I'll be sastified if I can maintain 190 plus or minus with repeated 1/4 mile runs.

Highway operation IMO is virtually the same as far as I can tell. Now, city driving may or may not be affected. I think a larger radiator, a different water pump, cooling fan and/or all of the above would be necessary to seriously impact the normal highway operating temperatures. The stock cooling system is just so marginalized, it's going to take more than a thermostat change to make a dramatic difference. Shoot, the stock fan doesn't kick in 'till 215 degrees if the A/C is off.
 
Okay then I'm just plain stupid then.But I was smart enough to make more power with a MarkVIII then anyone else in the world.Its been almost 4 years now and no one has been smart enough to make more power yet.And I run no T stat with both my street car and my race car with no ill effects whatsoever.

Oh, and Joe has one of the fastest street Marks out there and he also runs No T stat.I guess both of the fastest and most powerfull Mark builders are both Stupid.
 
driller said:
Highway operation IMO is virtually the same as far as I can tell. Now, city driving may or may not be affected. I think a larger radiator, a different water pump, cooling fan and/or all of the above would be necessary to seriously impact the normal highway operating temperatures. The stock cooling system is just so marginalized, it's going to take more than a thermostat change to make a dramatic difference. Shoot, the stock fan doesn't kick in 'till 215 degrees if the A/C is off.
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I agree, and have had the same results.
 
unstoppable said:
Okay then I'm just plain stupid then.But I was smart enough to make more power with a MarkVIII then anyone else in the world.Its been almost 4 years now and no one has been smart enough to make more power yet.And I run no T stat with both my street car and my race car with no ill effects whatsoever.

Oh, and Joe has one of the fastest street Marks out there and he also runs No T stat.I guess both of the fastest and most powerfull Mark builders are both Stupid.
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:eek:wned: :bowrofl:
 
I wasnt trying to "owne" anyone. I just dont take too well to being called stupid when I know what works in the real world.

It reminds me of a time when Dennis was having problems on the dyno and he thought he was running out of fuel pump.Jerry came on and talked all this techno mumbo jumbo about how the 255 walboro cant supply enough fuel to support 450 RWHP and thats why Dennis was runnig out of fuel.

I told them they were wrong and the problem was something else.They didnt believe me even after I told them just a week earlier I had my friends Turbo Supra on the dyno and it made 511RWHP with a single 255 walboro.SO if it will make 511 then it will make 450.

They argued and called me stupid and in the end I told them to check his fuel lines and see if it was pinched and sure enough it was.
I never got a thank you or even an apology but its okay It still felt good helping someone that doubted me and called me names.
 
Gees guys I made a funny below and nobody laughed , I hope you all , didn't take that post too seriously ... Ideal block temp is 200 deg for what its worth. I think if the water temp sensor for FI sees 160 there may be some issues with mixture control.. Along with a different opening temp , lower temp t-stats usually have a larger hole for more flow..Drag racing , we always ran on a cold motor starting only when time to run and then off as soon as possible , in some cases we towed from the finish line as not to heat the motor... Then cool off between runs till next elimination.Drag only cars don't have a cooling system...As far as no thermostat at all , it has been my experience that it is possible for the water to pass through the radiator too fast and doesn't get enough time to cool ... Thus water temp ,on hot days in that case , could continue to climb till overheat .I think with todays higher temp motors and smaller radiators this is probably closer to the norm not the exception.. In that case the Tstat controls upper limit also...I think under normal conditions with the proper size and functioning cooling system a 180 deg tstat should maintain 180 degrees ,plus or minus 10 degrees...I have found the engine temp to remain very constant in my car under all conditions, both highway and stuck in traffic.. What that is I am not sure Guage has no numbers , but I would guess 195..Guage damping might have some effect on small variations but not more than a few degrees..You guys running no Tstat and high temps with small tstats may have radiator flow problems...Just a thought ...
 
Topcat said:
Gees guys I made a funny below and nobody laughed , I hope you all , didn't take that post too seriously ... Ideal block temp is 200 deg for what its worth. I think if the water temp sensor for FI sees 160 there may be some issues with mixture control.. Along with a different opening temp , lower temp t-stats usually have a larger hole for more flow..Drag racing , we always ran on a cold motor starting only when time to run and then off as soon as possible , in some cases we towed from the finish line as not to heat the motor... Then cool off between runs till next elimination.Drag only cars don't have a cooling system...As far as no thermostat at all , it has been my experience that it is possible for the water to pass through the radiator too fast and doesn't get enough time to cool ... Thus water temp ,on hot days in that case , could continue to climb till overheat .I think with todays higher temp motors and smaller radiators this is probably closer to the norm not the exception.. In that case the Tstat controls upper limit also...I think under normal conditions with the proper size and functioning cooling system a 180 deg tstat should maintain 180 degrees ,plus or minus 10 degrees...I have found the engine temp to remain very constant in my car under all conditions, both highway and stuck in traffic.. What that is I am not sure Guage has no numbers , but I would guess 195..Guage damping might have some effect on small variations but not more than a few degrees..You guys running no Tstat and high temps with small tstats may have radiator flow problems...Just a thought ...
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When it comes to funnies, John, we're just a little slow. :biggrin: Opinions are one thing while experience is another. It's easy to get opinions, what I was after is exactly what you and others offered - practical experience. My contention was based on my previous experience and I hypothesized that the 160 degree t-stat would not yield engine temps of 160 degrees on my Mark VIII. I have arrived at these numbers for my temp gauge:

N-
O-
R-215(fan turns on)
M-200
A-180
L-160

Your's may vary, as it is my opinion the stock gauges are not necessarily that accurate - though I have had my chops busted for that comment. There is no doubt if the engine is not up to temperature, the EEC will not allow the engine to full potential, the exact method of which I am still learning. But in the same breath there is no refuting more power may be made with cooler engine temps. The EEC will begin to pull timing and power with increased temps above a certain limit. Early 4.6L DOHC Cobras had quite a fit with engine temps. It is this 'middle ground' we all run in with EFI and the cooler 'middle ground' is where the most power is all other things being equal.

I personally have seen examples of water pump/thermostat/radiator combos that would flow the coolant too fast through the radiator for heat dissipation. I suspect that is not a potential problem with our Marks from my experience with the stock cooling system. I would think no T-stat would be just as streetable as a 160 degree T-stat with the exception of longer warmup cycles. In moderate to tropical climates, it would probably be no issue at all.
 
I totally agree with you Driller.IN MY climate I have never once overheated or even come close for that matter, while running NO T stat.
Yes it will take a bit longer to warm up in the winter but it doesnt get that cold here anyway.

Joe lives in a lot colder climate and he has never had a problem either.
 
Well I gotta say after a few days and a nice highway cruise, I see no problems whatsoever running the 160 T-stat. I'm convinced you could run the stock cooling system with no thermostat as once you are on the highway, the engine temps are nowhere near the T-stat setting. Now if you start modding the water pump and/or radiator, all bets are off.
 
I put a 160 in the '95, because my friend had it laying around and the one that was in the car was stuck closed. The 25-30 mile drive to the shop, in bumper to bumper traffic, didn't seem to affect the car at all. I'm sure you'll be fine with it. :)
 
JoshMcMadMac said:
Cool driller. Glad that it works well! Any idea if it has affected your gas mileage?
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I haven't a clue. I get to drive my Marks so little, I really don't take mileage into consideration. Even if I checked the mileage now, I wouldn't have a known baseline to compare. Suffice to say I haven't noticed any. It would be suprising to me if it does since like I said, I can tell no difference at all in highway operating temperatures.

I'd say you nailed it when you wrote:

Another thing to remember is that the engine is still going to get warmer than the temp of the thermostat, and that the fans are still designed to come on at a stock setting for temperature, so you will most likely stay at the same temperature after driving the car for any length of time, regardless of the thermostat.
 
unstoppable said:
I totally agree with you Driller.IN MY climate I have never once overheated or even come close for that matter, while running NO T stat.
Yes it will take a bit longer to warm up in the winter but it doesnt get that cold here anyway.

Joe lives in a lot colder climate and he has never had a problem either.
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Hey Chris! I don't mean to start anything but Joe's red car didn't see any cold weather this past year. If tthats the one your talking about.
 
He told me he has taken the T stat out in both of his cars.He used to drive the pearl one every day in Wyoming with No T stat.

No problem at all.I'm just letting people know my personal experiences.
 
I don't care about a very few cars going w-out out of the millions and millions out there running with a t-stat. Though if your car is so powerful and built up then it is probably pushed hard and would require the full cooling your giving it. But for a car driven everyday its a bad idea. I'm not saying you are a stupid person just saying its a bad idea to advise people there aren't any problems with removing the thermostat. My dad had a maverick and neaver changed the oil the 3 years he owned it and never had problems. I wouldn't advise anybody to let there new car go 3 years on original oil and filter to save money on oil changes.

unstoppable said:
Okay then I'm just plain stupid then.But I was smart enough to make more power with a MarkVIII then anyone else in the world.Its been almost 4 years now and no one has been smart enough to make more power yet.And I run no T stat with both my street car and my race car with no ill effects whatsoever.

Oh, and Joe has one of the fastest street Marks out there and he also runs No T stat.I guess both of the fastest and most powerfull Mark builders are both Stupid.
Click to expand...
 
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