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What Temp Thermostat to Get?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by DuneRunner, Apr 29, 2002.

  1. DuneRunner

    DuneRunner 1/2 ton status

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    Ok Yesterday I jumped in and started the old K5 Up. (1983 w/ 350)
    And the temp was at about 150 (I think) which is about normal. Then 10 mins into the drive it went up to 210. Started to get worried. Then a minute later it dropped back down to regular temp. So its been about 2 yr. since I changed thermostats, and I'm curious what temp range yall are using for your thermostas. (I can't recall if the temps are totally right cuz the trucks at home unable to check gauge) I appreciate your help...
     
  2. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    I run a 192 and it never overheats or anything.

    rene
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

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    195, and I'll leave it at that because you didn't ask for opinions or thoughts /forums/images/icons/smile.gif
     
  4. Z3PR

    Z3PR Banned

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    I run the 160 degree Mr Gasket thermostat in all my V-8's !!! Ofcorse they all have been Chevys.
     
  5. DuneRunner

    DuneRunner 1/2 ton status

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    I do want to here what your experiences have been. I can't recall what I have in it now. But I'm wondering is there any benefits to haveing a hi temp thermostat vs. Low?
     
  6. DuneRunner

    DuneRunner 1/2 ton status

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    I do want to hear what your experiences have been. I can't recall what I have in it now. But I'm wondering is there any benefits to haveing a hi temp thermostat vs. Low?
     
  7. dogman

    dogman 1/2 ton status

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    Ken
    180 is what I usually run.
    If your engine is running cold, then move up in degrees.

    77K10,350,4sp< I ordered it new, that way .
     
  8. txbartman

    txbartman 1/2 ton status

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    I run a 180 and have been pleased. What you run depends on how your engine behaves and where you run. Here in TX, we don't get too worried about running cold. I contemplated running a 160, but the dang thing would just be open all the time. What would be the point. Didn't want to go up too much because it could tend to overheat.

    However, if you spend lots of time in a colder environment, the bottom temp may be your bigger issue, i.e. trying to keep it warm enough.
     
  9. dyeager535

    dyeager535 1 ton status Premium Member

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    Well, a 195 will give you better economy and will be more likely to "burn off" any condensation in the crankcase. As well, with the better economy, comes increased power, which is of course theoretical...

    Don't forget that engine tolerances were figured out with thermal expansion in mind, so running colder or hotter will throw those numbers off. Again, how much diff does it make? Without some exhaustive studies, we won't know. IMO, GM based their clearances knowing the operating temp of the engine, (195) so thats what I'm keeping mine at.

    As to cooler air/intake charge, thats all well and good when you are striving for max performance, and 14.7:1 mix isn't ideal, but for most other situations, 14.7:1 is "the best". If you cool EITHER the incoming air charge or the fuel, you end up with an air/fuel mix that isn't atomized very well, which reduces economy.

    On top of all this, colder oil is thicker, and takes more power to turn.
     
  10. Seventy4Blazer

    Seventy4Blazer 3/4 ton status

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    it gets rather hot out here in the desert, so in the summer i run a 165 and in the winter i run a 190.
    grant
     
  11. TopOff

    TopOff 1/2 ton status

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    Don't forget (if you have) fuel-inhjection, the computer relies on the engine to run between certain specified temperatures.

    That's what I would go by. If not, I would run about 180.
    Some computers require a 190 or 195 thermostat.
     
  12. DuneRunner

    DuneRunner 1/2 ton status

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    Thanks Guys. I've talked to my Dad and he recalls using a 185 in it in the past.

    My K5 is not EFI but that dose make sense. I'm going to get a 185 in a couple of hours (once I get out of this CUBICAL PRISION...Called work.) /forums/images/icons/wink.gif/forums/images/icons/crazy.gif/forums/images/icons/cool.gif

    2 more hours....Thanks again
     
  13. Triaged

    Triaged 1/2 ton status

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    I run a 160 degree Mr Gasket. When I get the cooling system done up the way I want I'll go to a 180.

    Hotter than 180* water temp will not get you more power...what it will do is raise the oil temp and that will give you more power. 170* water and 210* oil will get you the best power (but it isn't easy to keep the oil that hot).
     
  14. BigBri

    BigBri Registered Member

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    I run a 190 degree in my 84'. And it works just fine. Just remember that as you increase the temp your motor runs at you might have to compensate with higher octane fuel to keep it from detonating(pinging noise under accelleration) also the hotter you run your engine the more efficient it is(up to a certain point of course!) but for my K5 like I said I run a 190 degree t-stat with 89 octane and it runs like a dream.
     
  15. Thunder

    Thunder 3/4 ton status

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    180 to 195 is the best range of thermostat to run in a modern engine.
    180 will give you the best overall performance(non computer)
    195 will give better fuel economy. It is also the stat that computer rigs need for proper operation.
    In my opinion a 160 degree stat is too cold for a modern engine. It causes increased wear because the fuel does not combust completly and tolerances are tighter in the combustion chamber. Studies have found that wear at 160 degrees can be double that of 180 degrees.
    160 degree stats are mostly used in high compression engines that are running a lot of timing advance to stop pre-detonation. In applications where generating power is more important than engine longevity
     
  16. DesertDueler

    DesertDueler 1/2 ton status

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    Well, then I wonder what kind of life I can expect out of my boat motor. It doesnt get over 130 degrees in the middle of summer here in AZ. I just rebuilt the motor because I wanted more compression, other then that it was fine. My buddies boat runs the same temp, and the motor has lasted for 21 years and hasnt needed a rebuild. But both our boats are Fords so maybe thats why /forums/images/icons/wink.gif
     
  17. Z3PR

    Z3PR Banned

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    Soon or later, every V-8 I've owned gets a rebuild, and I've always pumped up the compression. I usely go for around 10 to 1 with the street cars. Never built a 400 sbc for a 4x4 befor. would 9.5 to 1 be good ???
     
  18. DuneRunner

    DuneRunner 1/2 ton status

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    The Parts store closed early yesterday. So I made sure I got into work early to sneek out early and work on the truck...*$#17 eaten grin*/forums/images/icons/crazy.gif Can't wait.... I think that a 185 is what I'm going to pick up after reading what yall have sugested. 4x4HIGH (Scott) works for a parts store and he is a machinest there so I'll probly pick his brain. Thanks A million.
     
  19. bigmack

    bigmack 1/2 ton status

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    130 degrees, man thats real cool. My boat runs at about 190-195 degrees. It has a vortec 4.3 V6.
     

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