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Should I Replace The Stock Fan With A Flex Fan

Discussion in 'Early CJ5 and CJ6 Tech' started by Speedybon, Aug 19, 2021.

  1. Aug 19, 2021
    Speedybon

    Speedybon Speedybon & Daisy

    Arroyo Grande...
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    Aug 2, 2021
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    I have been thinking about replacing my stock fan with a Flex fan. I want to stay away from going electric, for what and where I am driving cooling is not a problem what is your opinions is it worth it. And what size is a stock fan (225) engine fan? I think it's 16 inches? What I have works fine. Is it worth it replacing? Back in the early Eighties, a friend of mind about lost his arm when it threw the blade off, he was riving the hell out of it, and it was a flat fender jeep with a V8 without a shroud
     
  2. Aug 19, 2021
    Dne007

    Dne007 Well-Known Member 2024 Sponsor 2023 Sponsor

    Cypress, Tx
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    Hi, I did away with the solid original fan blade, it's just plain heavy, but a fan shroud is the icing on the cake. I think I bought a 15", I'd have to re-measure. I can get a pic if you'd like?
    dne'

    Derale Performance Plain Stainless Flex Fan

    I believe this is the fan shroud I bought, don't remember it being so much. It was kind of funky and did require some cutting of the fiberglass makeup.
    New Fiberglass Radiator Fan Shroud Fits 66-71 Jeepster Commando

    ps: how about a pic of your engine compartment?:shrug:

    [​IMG]
     
    Last edited: Aug 19, 2021
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  3. Aug 19, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    If you don't want electric, I'd suggest some production 7-blade steel fan, a thermal fan clutch, and a properly fitting shroud.

    I have tried the flex fans, and was not impressed. I have run both fiberglass and stainless, and they were both LOUD. Like tornado loud. The fiberglass fan broke a blade, and the stainless had sharp edges that cut if you got near them. I went back to the factory setup with a fan, clutch and shroud.
     
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  4. Aug 19, 2021
    Dne007

    Dne007 Well-Known Member 2024 Sponsor 2023 Sponsor

    Cypress, Tx
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    Yes, a fan clutch would be nice:D, but I'm happy:rofl: with my setup, a little testy with the bolts. However, explore all options;) :schooled:

    [​IMG]
     
  5. Aug 19, 2021
    Speedybon

    Speedybon Speedybon & Daisy

    Arroyo Grande...
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    Last edited: Aug 19, 2021
  6. Aug 19, 2021
    Speedybon

    Speedybon Speedybon & Daisy

    Arroyo Grande...
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  7. Aug 19, 2021
    Speedybon

    Speedybon Speedybon & Daisy

    Arroyo Grande...
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    I don't think there's room for a fan clutch I think that would be the way to go they work well.
     
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  8. Aug 19, 2021
    duffer

    duffer Rodent Power

    Bozeman, MT
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    I'm another that isn't a fan of flex fans in trail Jeeps. You can potentially be running some relatively high rpms while still barely moving and those flex blades are decreasing your air flow.
     
  9. Aug 19, 2021
    timsresort

    timsresort Active Member 2023 Sponsor 2022 Sponsor

    South Lake Tahoe CA
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    I have used this a few times, and it is going in my current build. But, if you don't have any cooling issues, I would leave the stock fan. It's fine for most situations.
    https://www.summitracing.com/parts/flx-1316
     
  10. Aug 19, 2021
    SFaulken

    SFaulken Active Member

    Bellevue, WA
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    You'd need to poke around with the search function a bit, but the Fan Clutch and Fan from a Volvo 740 fit just fine on many of these Dauntless rigs. I had a "how to" thread I did.

    I'm also another one that votes against flex fans. I've had a couple of them come apart at higher RPM's over the years, and as timgr said, they're noisy as hell.
     
  11. Aug 19, 2021
    Jw60

    Jw60 Sitting up n buckled down. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Sedalia MO.
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    If it ain't broke don't fix it.
    Also mind the pulley sizes.

    I've got overdrive pulleys on my 4.3 to help cooling and electric loads at idle.
     
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  12. Aug 20, 2021
    Dne007

    Dne007 Well-Known Member 2024 Sponsor 2023 Sponsor

    Cypress, Tx
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    Decisions decisions! :confused: My CJ is not a trail jeep, it will never see a trail while I own it, might sound kind of dumb owning a jeep, but this was a project which was quite fun and got a little closer to my friends here on the ECJ5. Yes, the stock fan would probably have been just fine. In fact, when I got the jeep, it had no fan shroud and many don't and do ok. I like the looks of the fan shroud, makes the engine compartment look completed. I have no cooling issues, the fan is quiet.

    Dne' with a story!!
    I have a story :sneak:, once upon a time when I was much younger, say 20ish, I had a '65 GT0 (I loved that car), actually a clone, was a Lemanns with a GTO front end with a 326 and 4 speed muncie transmission. It had a heavy solid fan and at higher rpm's was so noisy! I was going down a straight away, and got on it! omg, it was fun!! AT about 40-50 rapped out, the Alt light came on and I new the fan belt got thrown. I pulled to the side and coaxed it back on and went to my local HI-LO and bought a flex fan, I was so happy with it, it was super quiet and made my engine sound great even at higher RPM's. So, at that moment I was sold on flex fans. Guess it just depends on experiences throughout life as how one views the fans in general.

    Other:
    I recently removed the expensive dual electric fans off of my '67 Mustang, they worked great but were so stupid loud! I found a stock flex fan off of an early Ford with its spacer on ebay, media blasted and installed with a new fan shroud, worked much better than the elec fans and cooled the engine even better! The spacing between the blades must allow to get ones hands down to install the bolts, I would think. I know there was an extremely long 1/2 "wrench" to turn/tighten the bolts.

    The last pic is with the engine running/ can't see the fan:(
    [​IMG]
    [​IMG]

    [​IMG]
     
  13. Aug 20, 2021
    Boyink

    Boyink Super Moderator Staff Member

    Tulsa, OK
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    I have heard stories of flex fans getting pulled into the radiator during deep water crossings - if you ever expect to be in that situation it might be worth considering sticking with the stock type fan.
     
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  14. Aug 20, 2021
    Glenn

    Glenn Kinda grumpy old man Staff Member

    Apopka, Fl
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    Then you don't really have a need to change it. :)
     
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  15. Aug 20, 2021
    Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

    East Tennessee
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    "What I have works fine. Is it worth it replacing?"

    Why?
     
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  16. Aug 21, 2021
    RATTYFLATTY

    RATTYFLATTY I think you need a little more throttle

    Central MN
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    I'm another one for "just leave it if it works for you". But I too have an improved cooling system with a Waggy clutch fan, shroud, late model CJ grill and rad. It dose work great.
     
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  17. Aug 21, 2021
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    I've used flex fans in vehicles over the years, both fiberglass and stainless versions. Over time, they wear out and the blades fatigue and crack. I've found both pieces of blades missing as well as whole blades gone. Fortunately, no other damage evident.
    -Donny
     
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