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What's the best temp thermostat to run?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by bigk, Nov 16, 2001.

  1. bigk

    bigk 1/2 ton status

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    What\'s the best temp thermostat to run?

    I thought these motors were supposed to run best at 190 or so, but I'm tired of it running around 200, thinking about a 160. Any thoughts?

    Karl
    Temporarily Unemployed Underwear Model
    87 3/4 ton
     
  2. flblazer

    flblazer 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    i have a 190 in mine

    when will you learn you needto drive a a chevy an pull fords out of the mud or over themsame as a jeep some one move that ford b 4 i go over it
     
  3. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    I rnu a 195 in my 454... but that depends on the season (here in IL anyways) or it depends on your local weather. Sounds like yours runs a little warm, so maybe you could go for the 180* for the best results. If you go to 160*, you loose fuel economy (if you ever had any to start with [​IMG]). So think twice before dropping all the way to teh 160* stat.

    Good luck on your decision!

    <font color=red>GOT MUD???</font color=red>
    My license plate reads:<font color=blue> 8 YR SUV</font color=blue>
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  4. 1 FN HI K5

    1 FN HI K5 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    I agree 180 is the best one to run in k5 that's what im running in mine 350 tbi with 44's <font color=red>1 FN HI K5</font color=red>

    <a target="_blank" href=http://community.webshots.com/user/1fnhik5>http://community.webshots.com/user/1fnhik5</a>
     
  5. slider

    slider 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    I run a 185 degree balanced thermostat. Standard thermostats can be off as far as 10 to 20 degrees see http://performanceunlimited.com they have a good article on how well these thermostats work. I bought mine from Summit Racing
     
  6. '73 K5

    '73 K5 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    195

    '73 K5
    Chevy good...Ford bad
     
  7. mike reeh

    mike reeh 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    Ive found stant thermostats to be very accurate with my craftsmen voltmeter slash temp guage.

    anyways Id run a 180.

    your best bet is to run a fat radiater &amp; shroud.. maybe drill a 1/8" hole in your thermostat to bleed any air that might be trapped and to allow a slight bit of water to flow at all times..

    sometimes the case is that everything is working but the thermostat opens when its just a little too late... my truck has a stock heavy duty cooling system and im telling you its amazing how cool it runs... the upperhose is NEVER pressurized.. if you're going to buy a new radiator be sure to get it from radiator.com....

    anyways I wouldnt do the 160 thing.. the stat is doing its job by keeping your motor at 180.. its the rest of the cooling system that cant keep itself cool...

    thats my $0.02
    mike
     
  8. DesertDueler

    DesertDueler 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    stant 195s in both trucks. As for running 200 thats ok. Believe it or not the optimum temp is 205 for GMs. They like to run hot, just keep it under 220 and you are fine. BTW it also depends on where you have the temp probe at. For instance if its in the head it show hotter than if its at the t-stat.

    86Jimmy 4"&35"MTRs,87 burb 4"&35"MT,69Firebird w/525 hp,and 70GTO live in PHX,AZ<a target="_blank" href=http://www.geocities.com/modifierperformance>My vehicles</a>
     
  9. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: What\'s the best temp thermostat to run?

    Many times running to cool of a thermostat will cause it to run hotter. It opens to much and the coolant flows to fast through the radiator and doesn't have time to shed the heat. Bud had a SB 400 that had a overheat problem. He put a 160 in it and it got worse. put a 195 in it and it stayed steady as a rock at 200 and never oveheated again.
    I run 180's in both my carb trucks. idling on the trail with the A/C off they will run cool. On a FI truck you really need to run a 190-195. If it gets to cool the computer will kick back into cold start and will run rich.

    Women dig dents and flat paint!
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  10. Re: What\'s the best temp thermostat to run?

    i run 195 in the winter and 160 in the summer. i just put in a stant 195 and the truck runs right around 200 degrees.

    <font color=blue> Experience enables you to recognize a mistake when you make it again.

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  11. Thunder

    Thunder 3/4 ton status

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    Re: What\'s the best temp thermostat to run?

    If you have a computer controlled TBI in your truck keep the 195 degree thermostat . It is programed to operate at that temp. If you change the thermostat to a cooler one you should get a aftermarket prom chip for the computer. 160 degree stats aren't too good for modern engines. They cause more engine wear and get worse gas milage.

    To save me a lot of typing and a sore finger click the link below:
    <a target="_blank" href=http://performanceunlimited.com/illustrations/thermostats.html> All you may ever want to know about Thermostats</a>

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  12. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    I run a 160 in mine. I use an elec. fan only, and I live in Fla. which is why I went lower. Seems tho that no matter how much I drive it or let it sit and idle, it never builds pressure. You can hold the upper hose and its hot, but not <font color=red>HOT!</font color=red> I am putting in a different temp gauge this weekend to see what its really at.

    If ya can't stop.......Smile as you go under! [​IMG]
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  13. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Re: What\'s the best temp thermostat to run?

    I run a 195, because winter is coming and I like my heat to be warm! Even with a junk radiator, my cylinder head water temp gauge never reads over 195.

    As for the thermostat, what's that got to do with fuel mileage? Or are you referring to fuel injected engines only? Will they run in open loop with a lower temp thermostat?

    As far as I know, keeping the engine cooler than necessary is a good way of controlling detonation on a carburated engine.

    Tim
    '84 Chevy K10, lifted, loud, fast, and 3/4 ton axles
     
  14. DesertDueler

    DesertDueler 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    Running to cool robs horsepower too. For optimum power you need to be in between 180-195.

    86Jimmy 4"&35"MTRs,87 burb 4"&35"MT,69Firebird w/525 hp,and 70GTO live in PHX,AZ<a target="_blank" href=http://www.geocities.com/modifierperformance>My vehicles</a>
     
  15. Pure Insanity

    Pure Insanity 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    I drove mine quite a distance today and it FINALLY built up pressure! YEEAAAA! LOL! I was beginning to get concerned. It wasnt a BUNCH of pressure but firmed up the hose anyway. It was warm but still not <font color=red>HOT!</font color=red>Under 200 I would say. Never did get that gauge installed. [​IMG]

    If ya can't stop.......Smile as you go under! [​IMG]
    PIC of mine from flblazers site<a target="_blank" href=http://www.flblazer.alloffroad.com/photo3.html>
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  16. COOTER

    COOTER Registered Member

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    Re: What\'s the best temp thermostat to run?

    YEA WHAT IS THE DEAL ? I SEE THESE COOL RUNNING THERMOSTATS IN PERFOMANCE CATALOGS THAT PROMISE HP.BUT A FRIEND TOLD ME IF YOU RUN TO COLD YOU WILL BUILD UP SLUDGE ?
     
  17. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: What\'s the best temp thermostat to run?

    Tip. Typing in all caps is what is known as screaming in cyber land. It is also hard to read.

    Yes it could cause some problems with "Sludge". The engine is a big old hunk of steel and when the humidity is up and it goes through a temp change they will create condisation inside the block. That water will get into the oil and break it down. If the engine gets hot enough it will turn the water in the oil back into vapor and suck it out through the PCV.
    I wish I could find this site again that I ran across about a year ago. I linked to it somehow off a oil study. It was a small aircraft site but it had some great info about oil coolers and damaged caused by condisation in the crank case and how it was important for piston powered aircraft to run about 200 deg of oil temp to get that condinsation out.

    BTW Welcome to CK5 Cooter.

    Women dig dents and flat paint!
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  18. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: What\'s the best temp thermostat to run?

    Grim, good posts : )

    I'm going to add that although slight, when dealing with clearances of as small as .005 (or smaller depending) a 35 degree difference is pretty big, when talking about metal expansion. I haven't seen it yet, (I really should grab that book from my dad) but apparently GM did dyno tests with the different temps, and came to the conclusion it made very little difference in power.

    You are at a bit of a catch 22 with carbs and temperature. You want cool incoming air, but you want the gasoline hot. (cooling off the gas actually lowers the intake air temp)Problem is, they will attempt to equalize temp before they reach the cylinder. A cold intake will cause the fuel to puddle, (hence problem with a 160) too warm and you can have detonation problems. (Hence reverse cooling on some of the hi-po GM motors)

    As to the 160 keeping the engine cool, that is only true if you have a problem with spiking engine temps, that the extra 35 degree cushion between a 160 and 195 can solve. The engine should be able to be kept cool at 195 with no problems. (after all, that is the factory temp) The only difference between the two is the temp when the 'stat opens fully. If you can't keep it cool at 195, a 160 theoretically isn't going to make a difference, except as I said, if you have temperature spike problems. Think about it, the 160 has no advantage over the 195, both flow the same amount of water, just one at an earlier point. And if my physics is correct, all else being equal, the radiator will be more efficient at 195*(larger temp drop per pass through the radiator) than at 160.

    As well, closed loop/open loop is a factor, 160 is right about the limit on the CCC equipped cars, I'd imagine its the same or similar for EFI.

    I do of course, run a 195...350 with a 2 core radiator. Never budges over 195.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
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  19. COOTER

    COOTER Registered Member

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    Re: What\'s the best temp thermostat to run?

    ok better?
     
  20. TwoCrowsDesign

    TwoCrowsDesign 1/2 ton status

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    Re: What\'s the best temp thermostat to run?

    I think my 89 was stock with a 195, but I replaced it with a 185 which I'm starting to believe is the reason I can't get rid a rough idle problem that I've had. I know the algorithms that the ecm runs through can be fickle at times, particularly where temps are concerned.

    John
     

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