Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Thermostat temp rating

Discussion in '1969-1972 K5 Blazer | Truck | Suburban' started by JTB, Jun 2, 2001.

  1. JTB

    JTB 1/2 ton status

    Joined:
    Dec 5, 2000
    Posts:
    192
    Likes Received:
    0
    Location:
    CA
    I have read that running a lower t-stat will increase power due to a cooler air/fuel mix, but running one that is too low will shorten engine life. What temp rating is the best? 160 degree, or is that too cool?
    Jeff
     
  2. BobK

    BobK 1/2 ton status

    Joined:
    Oct 5, 2000
    Posts:
    1,604
    Likes Received:
    0
    Location:
    Petrolia,Ontario,Canada but working in Port Huron,
    160-180 deg F.Depends on your enviroment.If you live in a warmer part of the country you might want to go with the 160.

    <font color=green>BobK<font color=green>
     
  3. Dan71gmc

    Dan71gmc Registered Member

    Joined:
    Mar 4, 2001
    Posts:
    51
    Likes Received:
    0
    Most engines are more efficient at 180- 195 degrees, but I agree that it depends on your climate ,radiator condition, towing capability,etc. I run a 160 in my 63 Studebaker Avanti, a 180 in my 69 shortstep (but the heat in winter isn't so good), a 195 in the 2wd Blazer, and a 195 in the 4x4. Most will tell you it is a fine line between running a temperature that's efficient and overheating. You might want to experiment with a couple different thermostats and see. I like to see the needle on the left hand side, but cooler doesn't always mean better.
     
  4. Burt4x4

    Burt4x4 3/4 ton status

    Joined:
    Feb 17, 2000
    Posts:
    6,854
    Likes Received:
    0
    Location:
    California (Modesto area)
    I live in the Central Valley of California and 100 deg summer days is normal for us. I run 185 stat and also use Summit HighFlow waterpump and electric fan made by Flex-A-Lite the 2800cfm BlackMagic M150. My rig never goes above 200 in the summer and stays right at 185 in the winter. I feel this is perfict heat range for a 350.
    Good Luck

    72K5[​IMG]Led Zeppelin[​IMG]Rock ON![​IMG]
    <A target="_blank" HREF=http://www.burt4x4.coloradok5.com>http://www.burt4x4.coloradok5.com</A>
     
  5. Blazer1970

    Blazer1970 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,600
    Likes Received:
    0
    Location:
    Old Mission, MI
    If you live where it gets cold, a 195 is a good idea in a topless Blazer. With the 195, the heater works pretty good even with the top off. There is a big difference between having 180 degree water going through your heater core, and 195. The thermostat will not make a difference in overheating. If your cooling system can't remove the heat that the engine is making (HP = heat), a lower temp thermostat will not help.

    Tim

    70 Blazer CST 4X4 350 SM465 NP205
    87 Burb 4X4 350
    01 GMC 2500HD 4X4 Duramax/Allison
     
  6. 2quicK5

    2quicK5 Registered Member

    Joined:
    Apr 18, 2001
    Posts:
    46
    Likes Received:
    0
    Location:
    TN
    General rules of thumb:

    195 F for passing emissions testing and gas mileage

    180 F good all around compromise for daily driving, light towing and moderate performance usage

    160 F for heavy performance usage (racing) and heavy towing.

    John

    1972 K5 Blazer: 400 ci, 4 sp, 4" springs, 35" Tires

    2000 Trans Am, A4
    11.97@114 mph
     
  7. Steve_Chin

    Steve_Chin 1/2 ton status

    Joined:
    Mar 6, 2001
    Posts:
    1,126
    Likes Received:
    0
    Location:
    Foster City, CA, USA
    Blazer1970's last sentence is *very* important!

    FWIW, I am running a 160 degree Robertshaw thermostat in my Blazer, but I am thinking that I will get better fuel economy with a slightly hotter thermostat, so I am considering a 180. The difference in the amount of wear you will see from a 160 to a 180 is not extremely high, as it is the oil temperature that is more important in considering most wear factors. Keeping the oil temperature between 185 and 220 degrees F is important.
     

Share This Page