serpentine upgrade, fan almost went through hood. Anyone done this with a flex fan?? pics inside

Discussion in 'The BS Topic' started by QUAKE_WARS, Oct 17, 2020 at 12:08 AM.

  1. QUAKE_WARS

    QUAKE_WARS Veteran Member

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    I put this in BS section because this is in my 85 k20 4x4.

    I got tired of the single belts and issues. I put a 1992 trans am single belt serp setup.
    it worked perfect. I put a small electric fan in front of 4 core radiator and truck ran about
    210 to 205. Not good for a SB 350. I spent $93 for a reverse flex fan and 3 1/2 inch spacer.

    I have done this swap at least 15 times with no issues, but only using electric fans.
    The first time I use a flex fan (reverse rotation) at 5600 RPM it blew up!!:mad:

    My question is are these water pumps not suppose to use fans?? as no cars were ever
    equipped with fans on the water pumps, only electric fans!

    Anyone ever done a serpentine swap and used a flex fan with success?
    Here is whats left of it. Fan had 20 minute drive time lol. Pulley broke right
    at the shaft. everything else was just in the way. So much for the 4 core radiator.


    20201016_210244.jpg 20201016_210337.jpg 20201016_210458.jpg 20201016_210620.jpg 20201016_210945.jpg
     
    Last edited: Oct 17, 2020 at 12:14 AM
  2. QUAKE_WARS

    QUAKE_WARS Veteran Member

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    more 20201016_211018.jpg 20201016_211802.jpg 20201016_211958.jpg 20201016_212429.jpg
     
  3. QUAKE_WARS

    QUAKE_WARS Veteran Member

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    HOT AUG 1235.jpg
     
    Coadster32 and GoldenOne7710 like this.
  4. gramps

    gramps Veteran Member

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    Nice lookin truck. Love those square bodies.

    unfortunately that’s a problem with flex fans. Take a paperclip and bend it back and forth a few times, it breaks off. Same thing happens to the flex fans, especially at high rpm. I’d venture a guess if you looked at the box it came in it probably says “for use under [insert some ridiculously low rpm like 3k] rpm only”

    had one guy come in and after the 4th fan he was “defect” warranty returning i happened to be up at the front counter and heard him say every time he shifts at 5000 the pos fan lets go.
     
  5. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

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    This is the exact reason I dislike flex fans.
    FYI electric fans need to be on the engine side of the radiator to work properly. It’s much more efficient to draw the air through the radiator than push it against.
     
  6. biker

    biker Veteran Member

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    Ouch. Beautiful truck! So the pulley/shaft broke...not necessarily the fault of the fan, but as the other guys said, flex fans are generally garbage. I'd guess that pulley/shaft was never engineered to support the load that a fan can put on them, especially a questionably balanced flex fan hanging off the end of a 3" spacer.
    As Lowend said, if you use a properly sized electric fan to pull air from the engine side, that is way better than a push fan, and certainly better than a flex fan.
    The right electric fan(s) and shroud will work perfectly and look clean under your hood. A flex fan just screams cheap when you pop the hood open.
     
  7. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    I used a flex fan on my 65 pickup with the original engine from my 79 Z-28. That was a short lived situation, too much noise and vibration. I tossed it in the dumpster, didn't want to see my, or anyone else's hood, radiator, and whatever else destroyed.

    You can get a set of LS1 electric fans for around $125 from EvilBay. I'm using these on my Camaro now.

    Nice looking square body, good luck with this.
     
  8. carhead22000

    carhead22000 oldblue

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    lost a fan blade on my Camaro. Soon as I hit second gear on the shift kit it popped right through my air induction hood. Thought I broke a motor mount.lol..them fans are crap.i went with electric fan after that. Never looked back.
     
  9. biker

    biker Veteran Member

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    LS1 fans are my next upgrade too.
     
  10. GoldenOne7710

    GoldenOne7710 Equal Opportunity Offender Lifetime Gold Member

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    That's some serious carnage. Put me down as another who dislikes rigid mount fans...especially Flex fans. I'll take a good ol clutch fan any day.
     

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