Spring "wake up" cooling issues

Discussion in 'Street/strip 400/430/455' started by 1969RIVI, May 5, 2019.

  1. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Ditch the electric fans. No reason for them. My engine is cooled by a stock 18" 7 blade fan, reproduction 70 shroud, and stock fan clutch. With a 180 stat, it runs right at 180 or a bit below.
     
  2. 1969RIVI

    1969RIVI Well-Known Member

    I did that Larry the new stat is working properly and the gauge is reading around the same temp at the time it opens then drops. I thought maybe a corroded temp sensor is giving me an off reading? As for the electrics I haven't checked the grounds but nothing is going wonky
     
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I don't like electric fans. Unless they are running full time, they block air flow. Can you go back to a stock clutch fan? I would do that just to see what happens.
     
  4. 1969RIVI

    1969RIVI Well-Known Member

    I've read the countless debates on electric fans VS stock blade fans and I've thought about going back to a stock set up to try it out. My only issue is the fan,clutch and shroud are long gone, the P.O. did the swap with the engine and I don't have the parts.
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    I think you have exhausted all the other possibilities. I'd look into getting the right stock pieces. It's not that hard to find. You may come to that conclusion on your own. If a stock set up cools my 600 HP beast, it can cool your engine.
     
  6. 1969RIVI

    1969RIVI Well-Known Member

    I think you're right Larry, I might as well give it a shot and see if it works. I'm not to concerned about concours number matching parts, just good working ones my car is well past original.
     
  7. 1973gs

    1973gs Well-Known Member

    I agree that a mechanical fan can cool as well as an electric fan.I'm a little over 700 hp and have two electric puller fans mounted in an aluminum shroud that covers 100% of the radiator. I have a 180* thermostat and my car has never seen 200*, almost always runs at around 190. I used electric fans because that's what all the cool kids use!:cool: Actually, I just didn't think that a mechanical fan looked right in a prostreet car. Before you over think this anymore, drain all of the af out and save it. Fill the cooling system with water and go drive the car. If it runs a lot cooler, there's your problem. If it runs the same, reinstall your af and continue diagnosing. I wouldn't switch back to a mechanical fan unless the electric fan is causing your problem. If you ran the electric fan last season without any problems, it's probably fine unless the new aluminum radiator is not as efficient as the old radiator. If that's the case, you may be better off with a mechanical fan.
     
    Last edited: Jun 8, 2019
  8. 1969RIVI

    1969RIVI Well-Known Member

    1973gs I think I'll try that first it's a cheap test before I get into more $$ in parts. My fans are puller fans and the shroud covers 100% of the radiator also. I hand built it to fit tight to the rad and the holes are cut to the diameter of the fans. My AC rad is in front of my aluminum rad right now I thought of removing it to get more airflow but I would eventually like to get my AC working again so I left it in there.
     
  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    100% distilled water and WW is the ultimate in heat transfer. The WW has all the anti corrosives and additives for pump seals and such. The only time you really need anti freeze is for freeze protection. OEM fans do a great job with late model cars, but like I said, a stock set up cools my car, and it runs at the stat temperature. Anytime you see your temperature go 20* above the stat rating, it means the stat and system have lost control of the temperature. The stat is fully open at 20* beyond the opening temp. At that point, it can't do anymore.

    As far as I am concerned, electric fans block air flow if they are not turning, and the shrouds for them are usually pretty shallow from what I have seen in the aftermarket. A mechanical fan is way better IMHO.
     
  10. bostoncat68

    bostoncat68 Platinum Level Contributor

  11. 1969RIVI

    1969RIVI Well-Known Member

    Nothing as of yet. I've been waiting for the temps to get a bit warmer then I'm going to try 3 things.
    1) drain the system and use straight distilled water and water wetter and test run it to see if it helps reduce temps
    2) buy another gauge and sender to see if one or the other my be going bad and check all my electrics/ grounds while I'm at it.
    3) if the two above fail, start collecting the stock fan parts and swap back to see if it helps.
    I'm also debating pulling the intake off to make sure the heat crossover is plugged because it could be making my performer intake hotter and since the temp sensor goes into it maybe that's wher the extra heat is coming from and my gauge is reading that it's running hot, but in actuality it's not. I also added the TA BHP pump last season and it helped a bit.
     
  12. bostoncat68

    bostoncat68 Platinum Level Contributor

    I'm just struggling to believe this is a fan issue (not sure why..but I see it that way since it worked prior). I think either the radiator is at fault, the water pump is losing steam or you have faulty readings. I think I would buy an infrared thermometer to check the temp of stuff coming in and out...
     
  13. 64 skylark mike

    64 skylark mike Well-Known Member

    Since you have a different radiator, does the new shroud align with the depth of the fan the same as the old setup did?
     
  14. Schurkey

    Schurkey Silver Level contributor

    That's going to be a good share of the problem. Shrouds for electric fans need to have closable louvers so air can blow through when the car is moving forward, but shut when the fans are running at stops and low speed. You're probably blocking air flow through the radiator with a shroud like that.

    That would be the LAST thing I'd do.


    Good first move. Verify the problem.

    I'm not a big "fan" of electric fans on big V-8s. It takes a monster fan or two to make that system work. The original clutch fan 'n' shroud is simple, cheap, effective.

    You'd want to assure that you don't have a restricted exhaust--a seized heat-riser valve, or a restriction on one side of a dual exhaust, (such as a crushed tube, or an obstructed inner tube in a double-wall exhaust pipe) that would force excess hot exhaust gas through the intake manifold heat crossover passage. If the exhaust system isn't restricted, the heat crossover in the manifold is NOT the reason the gauge is reading high temperature.
     
  15. 1969RIVI

    1969RIVI Well-Known Member

    This is what my fan and shroud set up are like.
    https://images.app.goo.gl/YeoLae9DdM4MqGPVA
    The exhaust is free flowing with no restrictions what so ever.
    The rad, water pump, thermostat and housing are all brand new.
     
  16. Schurkey

    Schurkey Silver Level contributor

    Yup, that's what I was afraid of.
     
  17. 1969RIVI

    1969RIVI Well-Known Member

    Here's a pic (not the greatest angle/shot) of my rad shroud and fans setup. I've seen pics of shrouds with holes cut in the flat spots with rubber flaps over them. I know summit sells the flaps. There's not much flat spots left around my fans but maybe I could add a few ??
     

    Attached Files:

  18. Mark Demko

    Mark Demko Well-Known Member

    Just curious, but wouldn't the airflow going thru the rad while driving be enough to turn the fan blades allowing air to pass thru if the fan is not running?
     
  19. 1969RIVI

    1969RIVI Well-Known Member

    Mark that was my thoughts also but it seems that everyone says otherwise?o_O
     
    Mark Demko likes this.
  20. Mark Demko

    Mark Demko Well-Known Member

    The only reason they WOULD NOT spin that I can think of is that the pitch on the blades may not be enough when air hits them causing them to spin, they're too "flat" so to speak.
     

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