Over heating on the freeway?

Heating / Cooling / AC

  1. Cope

    Cope Fusing with fire

    Messages:
    2,445
    Likes Received:
    1838
    Joined:
    Oct 20, 2009
    Location:
    San Jose, Ca.
    Local Time:
    1:30 AM
    71 dart, new 360
    New griffen cross flow radiator. Restrictor plate in T stat housing.
    Large eletric puller fan and shroud.
    All new hoses.

    The car is fine around town, 180-190 but get on the freeway and the temp just cimbs...

    This is so backwards from all other cars I've ever owned I'm not sure what gives?

    Any ideas?
     
    • Agree Agree x 1
    • krazykuda

      krazykuda FABO Gold Member FABO Gold Member

      Messages:
      46,014
      Likes Received:
      11134
      Joined:
      Aug 20, 2007
      Location:
      Orland Park, IL
      Local Time:
      1:30 AM
      How well is the radiator sealed to the shroud and opening??? It may be that the ram air that's supposed to be going THROUGH the radiator is going AROUND it....
       
    • RAT ROD AL

      RAT ROD AL FABO Gold Member FABO Gold Member

      Messages:
      904
      Likes Received:
      661
      Joined:
      Jan 18, 2013
      Location:
      St. James City. FL.
      Local Time:
      2:30 AM
      Where you trying to keep up with that VIPER? LOL That would do it.
       
      • Like Like x 1
      • Cope

        Cope Fusing with fire

        Messages:
        2,445
        Likes Received:
        1838
        Joined:
        Oct 20, 2009
        Location:
        San Jose, Ca.
        Local Time:
        1:30 AM
        The shroud is sealed very well.

        I'm about to take it off and see what happens.
         
      • Cope

        Cope Fusing with fire

        Messages:
        2,445
        Likes Received:
        1838
        Joined:
        Oct 20, 2009
        Location:
        San Jose, Ca.
        Local Time:
        1:30 AM
        Lol, no
        No viper involved today...
        Just wanted to take my lady for a cruze.
         
      • RAT ROD AL

        RAT ROD AL FABO Gold Member FABO Gold Member

        Messages:
        904
        Likes Received:
        661
        Joined:
        Jan 18, 2013
        Location:
        St. James City. FL.
        Local Time:
        2:30 AM
        Is this your race car you where talking about earlier ? New build ? And whats with the restrictor in there? No thermostat?
         
      • famous bob

        famous bob mopar misfit

        Messages:
        11,233
        Likes Received:
        2783
        Joined:
        Aug 14, 2011
        Location:
        okla
        Local Time:
        1:30 AM
        A hood scoop that's not sealed to the carb. can cause that very problem, if the scoop is pulling in a lot of air and fighting the rad. airflow..
         
        • Agree Agree x 1
        • OL DODGE

          OL DODGE Well-Known Member

          Messages:
          179
          Likes Received:
          68
          Joined:
          Mar 25, 2012
          Location:
          Fairview Park,Ohio
          Local Time:
          2:30 AM
          What gears out back and what kind of rpm on the highway ? Which water pump is on it?
           
        • MOPAROFFICIAL

          MOPAROFFICIAL Well-Known Member

          Messages:
          2,928
          Likes Received:
          1928
          Joined:
          Jun 1, 2016
          Location:
          breakwater
          Local Time:
          11:30 PM
          Shouldn't even need a fan at freeway speeds.
          The under carriage opening around the engine will let the air escape, so forget the hood scoop idea.
          The fan, if on, could be blocking "not keeping up" ..the other issue is usually a capacity one...or you have too much timing and it's just pinging...or even too retarded.
           
          Last edited: Aug 26, 2018
          • Agree Agree x 1
          • 4spdragtop

            4spdragtop FABO Gold Member FABO Gold Member

            Messages:
            24,952
            Likes Received:
            4261
            Joined:
            Aug 28, 2009
            Location:
            Ontario
            Local Time:
            1:30 AM
            Ok, I dont know much, but I've read a few threads on cooling as I had an "issue" with our 67 cuda. 200 on highway and 185-190 in town. 273 4 bl, factory 3 row rad, new water pump(8 vane) last year. factory shroud. WAS running 190 stat. Timing cover coolant leak for the 2nd time in 2 years. Put a 160 stat in it and now it has not gone over 175*.
            No disrespect to all the theories and such but I got a 35* temp reduction by changing tstat. $12.
            Good luck.
             
          • Garry in AZ

            Garry in AZ Building a 9 second Valiant FABO Gold Member

            Messages:
            234
            Likes Received:
            218
            Joined:
            Jul 13, 2017
            Location:
            Mesa, AZ
            Local Time:
            12:30 AM
            Hmmm..... the car cools fine at low speeds, but overheats on the highway. Is it possible that you have a "pusher" fan installed on the engine side of the rad, and when you drive highway speeds the fan is fighting the normal airflow? Just a wild ass guess Cope, but I've seen stuff like that accidentally happen even at the highest levels of motorsport.
            Please let us know the outcome of this, it's really interesting.
             
          • 72bluNblu

            72bluNblu FABO Gold Member FABO Gold Member

            Messages:
            9,037
            Likes Received:
            3010
            Joined:
            Nov 28, 2008
            Location:
            NorCal
            Local Time:
            11:30 PM
            A temperature problem at freeway speeds is almost always a radiator problem.

            Seems like you’re the second person with a brand new Griffin cross flow that has cooling issues...

            Easy, you changed a broken thermostat for a good one. The thermostat temperature change has no part of it, besides the extra wear and tear you’re putting on your engine running it below ideal temperature.

            The thermostat only sets the low temperature. If it effects anything other than the low temp, it’s not operating properly.
             
          • Dana67Dart

            Dana67Dart Most undignified way to get to Colorado!

            Messages:
            1,541
            Likes Received:
            612
            Joined:
            Jul 16, 2017
            Location:
            Northern Colorado
            Local Time:
            12:30 AM
            Im so Confused...My stock dart, 273 2bbl , no shroud (factory) stock fan inches from face of radiator (factory), correct thermostat, stock radiator, average water pump, no overheating issues.
             
            Last edited: Aug 26, 2018
          • MOPAROFFICIAL

            MOPAROFFICIAL Well-Known Member

            Messages:
            2,928
            Likes Received:
            1928
            Joined:
            Jun 1, 2016
            Location:
            breakwater
            Local Time:
            11:30 PM
            410 CID
            1 " single cross row BMW radiator
            18" fan
            No shroud
            8 blade stock water pump
            Exh cross over blocked
            High flow 180 t stat
            16lb release rad cap
            10.1 static comp
            8.88 dynamic comp
            Pump gas
            Never overheats.
             
          • MOPAROFFICIAL

            MOPAROFFICIAL Well-Known Member

            Messages:
            2,928
            Likes Received:
            1928
            Joined:
            Jun 1, 2016
            Location:
            breakwater
            Local Time:
            11:30 PM
            That's a good idea on the fan, backwards is a possibility, or it's just blocking the air at high speed once it cant keep up.
             
          • Cope

            Cope Fusing with fire

            Messages:
            2,445
            Likes Received:
            1838
            Joined:
            Oct 20, 2009
            Location:
            San Jose, Ca.
            Local Time:
            1:30 AM
            The fan is pulling I can feel it out the back and it would over heat in traffic it that was wrong.

            I like the idea of the fan not keeping up at freeway speed. I'm running about 2500 rpm at 45 50 MPH. no speedometer, yes race car..

            This is definitely an engine that's pushing the limits of streetable.
             
          • 4spdragtop

            4spdragtop FABO Gold Member FABO Gold Member

            Messages:
            24,952
            Likes Received:
            4261
            Joined:
            Aug 28, 2009
            Location:
            Ontario
            Local Time:
            1:30 AM
            Old 190 thermostat wasn't broken.
             
          • Cope

            Cope Fusing with fire

            Messages:
            2,445
            Likes Received:
            1838
            Joined:
            Oct 20, 2009
            Location:
            San Jose, Ca.
            Local Time:
            1:30 AM
            20180817_170839_zpsskqltfwn.jpg

            Best pic I have of the fan and shroud right now.
             
          • MOPAROFFICIAL

            MOPAROFFICIAL Well-Known Member

            Messages:
            2,928
            Likes Received:
            1928
            Joined:
            Jun 1, 2016
            Location:
            breakwater
            Local Time:
            11:30 PM
            Well look at that... that shroud, and now If air goes around the radiator easier than through at speed, which path do you think it would take?
            Lose the shroud, its blocking more air than directing... mount the fan straight to radiator.
            After that, if you still have issue...then you must seal up that core support area, seal the sides of the radiator to support.
             
          • Cope

            Cope Fusing with fire

            Messages:
            2,445
            Likes Received:
            1838
            Joined:
            Oct 20, 2009
            Location:
            San Jose, Ca.
            Local Time:
            1:30 AM
            Yeah so pull the shroud right?

            That's a major pain in the ass. It riveted to the radiator. But I think you guys are on to something.
             
            • Like Like x 1
            • Dana67Dart

              Dana67Dart Most undignified way to get to Colorado!

              Messages:
              1,541
              Likes Received:
              612
              Joined:
              Jul 16, 2017
              Location:
              Northern Colorado
              Local Time:
              12:30 AM
              IMHO your blocking 1/3 of your radiator with the shroud. Factory shrouds have space from the shroud to the radiator face and typically have a shape to promote flow.
               
            • Dana67Dart

              Dana67Dart Most undignified way to get to Colorado!

              Messages:
              1,541
              Likes Received:
              612
              Joined:
              Jul 16, 2017
              Location:
              Northern Colorado
              Local Time:
              12:30 AM
              Last thing I notice about the fan. It has alot of grill slats.

              THink about your attic eve vents. it might cover 12"x 4" (48 sqin) but with the screen in there to keep critters out you are down to maybe 2/3 of that so maybe 32 sqin

              Your fan is the same, measure the open space and you might see that you only have 1/2 the sqin of open space where air can flow through. look at the sqin of the radiator and the sqin of the opening for the fan maybe 2/3 of the rad sqin. I think all of this is the problem. loose the shroud and see what happens.
               
            • Cope

              Cope Fusing with fire

              Messages:
              2,445
              Likes Received:
              1838
              Joined:
              Oct 20, 2009
              Location:
              San Jose, Ca.
              Local Time:
              1:30 AM
              I do have flappers to let air out of the shroud at speed. But yeah I'm gonna try with out it.

              That easy just pull radiator, drill out 35 40 rivets with out hitting the rad, build a new fan mount and test... easy peasy....

              :)
               
              • Like Like x 1
              • 67Dart273

                67Dart273 Well-Known Member

                Messages:
                38,642
                Likes Received:
                6247
                Joined:
                Oct 14, 2010
                Location:
                Idaho
                Local Time:
                11:30 PM
                You should not even need a fan above about 35--40. On electric setups there's been talk that some electrics actually REDUCE highway airflow, you need trap doors in the shroud to bypass them

                Any chance the belt is slipping?

                EDIT somehow didn't see the post above, LOL. Can you take the fan OFF and run a short trip, don't know how close you are to the highway?
                 
              • kursplat

                kursplat FABO Gold Member FABO Gold Member

                Messages:
                1,040
                Likes Received:
                268
                Joined:
                Aug 24, 2010
                Location:
                so cal
                Local Time:
                11:30 PM
                man, nothing with "race car" and "pushing the limits of streetable" should be that difficult to disassemble :rolleyes:
                 
                • Like Like x 2
                1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
                  By continuing to use this site, you are consenting to our use of cookies.