393w overheating.

Discussion in 'Technical' started by 29EssexRat, Jun 18, 2021.

  1. 29EssexRat

    29EssexRat Member

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    So I'm having trouble keeping my motor cool. It steadily climes to 200 degrees, and then I shut it down, today it got to 210ish and started detonating because I was driving up a hill couldn't pull over :banghead:. Weather's pretty hot here, 80-100 all day. I don't think it overheats when it's cooler out, but also didn't drive it too far then. Takes a while for it to overheat, maybe 10 minutes? Don't think it'd overheat when just idling, but haven't let it idle long enough.

    - Gauge is accurate.
    - Motor is a 10:1 393ci 351w, big cam, crites headers
    - built trans, 3,000 stall
    - champion 3 row radiator, 180 degree thermostat (checked before installing), 185 Degrees On/175 Degrees Off electric fan switch
    - Timing is 34 at 3000 rpm, 15 below 1,000 rpm
    - Using a foxbody mustang type serpentine belt setup, water pump spins counterclockwise
    - I have a derale 13750 transmission cooler in front of the radiator, but I wouldn't imagine that would be an issue.
    - Headgaskets (felpro 10112) should be installed properly, I was very meticulous when installing the heads, and you can see both tabs of the headgasket sticking out at the front of the motor.
    - Shouldn't be any air bubbles in the cooling system, as I initially burped the system, and have driven it enough.

    I'm lost, thinking of putting a 160 thermostat and fan switch in it, but that feels more like a bandaid for a bigger issue. And prob won't change anything besides the minimum operating temp.
     
    Last edited: Jun 18, 2021
  2. jasonwthompson

    jasonwthompson Member

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    Is this a new build never before run or is this a new problem on a previously working engine? What electric fan are you using? High compression, large cam will run hot, horsepower makes heat. Decreasing the thermostat temp will probably make it worse as it will stay open and never close, you may want to go the other direction with a 190-195.
     
  3. 29EssexRat

    29EssexRat Member

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    Everything's new. How would going the other direction help? Decrease flow to allow time for heat transfer?
     
  4. 29EssexRat

    29EssexRat Member

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    The electric fan is what came on the champion radiator. Along with a "shroud"
     
  5. TeeEl

    TeeEl Member

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    Is this at idle, or at cruising speeds?
    If at idle, what is the cfm rating of the fan? Is your trans cooler through the radiator, or separate? If you have aluminum heads, you should be able to run 38 degrees of total ignition advance, although 15 at idle should be fine...
     
  6. jasonwthompson

    jasonwthompson Member

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    Exactly, once the engine warms to operating temp, a 160 thermostat may never close, which would be much like running without a thermostat at all. I have a fairly stock 302 H.O. that runs around 200 - 210 in stop and go traffic without any problems. IIRC it is a 190-195 thermostat in it. I am assuming this Windsor is a late model with the correct timing cover and water pump to spin counter clockwise with a serpentine setup?
     
  7. 29EssexRat

    29EssexRat Member

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    I drive it pretty hard, get on it a bit at the stop lights and such, but even on the highway it was getting hot, which you'd think would have enough airflow to not be a fan issue? I haven't let it idle for very long, and am at work now, but will let it idle tomorrow and get back. Norm when messing with it, at idle it stays at 185ish. I'll look for the fan cfm too.
     
  8. 29EssexRat

    29EssexRat Member

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    Yes, correct waterpump and belt rotation. I can't run 210, as at 210 it started detonating. Need it to run 180-190 :/
     
  9. Krazy Comet

    Krazy Comet Tom

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    If cooling system is sufficient, engine clearance not to tight etc, installing a 160* thermostat SHOULD make engine operate in 160*-170* range. Open thermostat is allowing for more cooling, not less.

    Be nice to know what CFM the fan rating. Is there a shroud, or is fan mounted directly to radiator?
     
  10. 29EssexRat

    29EssexRat Member

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    Cant find the exact fan my rad came with (will look for numbers after work) as I bougbt it off eBay from a ledfootracing who's not active anymore, but their site takes me to champions side (maybe name change?), and the rad there comes with a spal-1516 or spal-1517 which are only 1600/2000 cfm. Definately doesn't sound like enough. Does have a shroud.
     
    Last edited: Jun 18, 2021
  11. jasonwthompson

    jasonwthompson Member

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    If it idles without overheating, but not on highway, check the lower hose to see if it collapses at higher draw (rpm).
     
  12. 29EssexRat

    29EssexRat Member

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    Ah yes. Will do
     
  13. Fastkarz

    Fastkarz Member

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    I installed my new 347 to replace my 302 and used an aluminum radiator with Electric fans. Same overheating issue you describe. I chucked the electric fans, installed a factory mechanical fan and fan shroud and have been driving without overheating in New Jersey traffic. The Electric fans or the shrouding they are installed in may not allow enough CFM. My 347 is a 10:1 aluminum head roller cam block, 180 tsatat with a 3000 stall AOD and 4.10:1 gears. It got enough power I dont feel any real drag with the mechanical fan.
     
  14. 29EssexRat

    29EssexRat Member

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    Hmmm, sounds like a comparable build. I think I'll check a few things mentioned above, buy a true 3,000cfm fan. And if that doesn't work put on a mechanical fan setup. With the serpentine belt I dont think the mechanical fan will fit which is a big negative for me. But oh well.
     
  15. TeeEl

    TeeEl Member

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    No and Yes.
    The opening temperature of the T-stat DOES NOT determine the maximum temp that the engine runs at. The cooling system's ability to exchange heat does. The T-stat determines the MINIMUM engine temperature.

    Yes, an open T-stat would make it run cooler, providing that the rest of the system is not defficient.

    On another note; it is a MYTH that slowing the coolant flow cools better as a result of giving "more time" for the radiator to remove the heat. Coolant that flows too fast can cause cavitation and aeration, both of which reduce cooling ability. The radiator's job is to exchange the heat from liquid to air. It does not need "time" to do this, as airflow and coolant flow are constant, so it's constantly exchanging heat. Heck, the more time the coolant in the radiator is in there, the more time the coolant in the block & heads is in there, getting hotter and hotter before it can enter the radiator. So slowing the coolant flow is not helping in that manor. You just need to avoid cavitation & aeration.
    Unless you're driving your Maverick in Alaska during winter, a 180-degree thermostat is just fine. No need to go hotter. I run a 170 in mine, but it was a special order and 50 bucks (not really worth it). I've seen where cars with a 160 T-stat still run at 210 or 220 because that's the best the cooling system can achieve.

    If everything else is working like it's supposed to, I'd focus on airflow. More rows in a raditor requires more airflow...
     

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