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Clutch Fan

Discussion in 'Intermediate CJ-5/6/7/8' started by clarkent, Jun 29, 2010.

  1. Jun 29, 2010
    clarkent

    clarkent Member

    Griswold, CT
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    Jan 19, 2008
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    I've been debating going to a clutch fan in my 74. Anyone got any reasons why this is a great or really bad idea?
     
  2. Jun 29, 2010
    nwedgar

    nwedgar Now with TBI!

    Newnan, Georgia
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    Why not electric if you're considering a change?

    A Ford Contour fan is a perfect fit over the radiator, and it can be wired redundantly as there are two fans. It's worth a consideration...I'm sure a search here and on the web will turn up lots of info.
     
  3. Jun 29, 2010
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    The factory fan and fan clutch will make your engine quieter at speed. Try taking the fan off and you'll see how much of the engine noise is fan noise (a lot).

    That said, the only thing the factory fan clutch has over the electric fan is simplicity, IMO. The electric fan is less efficient (in turning fuel into cooling air) but gets back that loss of conversion power by running only when needed.

    The factory fan, fan clutch and shroud works well though. Certainly quieter than a fixed fan.
     
  4. Jun 29, 2010
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    Clutch fans are great for water crossings. Ease into the water. When the fan hits the water it will stop and not take out the radiator.....AMHIK. If running electric it also can be turned off.
     
  5. Jun 29, 2010
    1974Sixer

    1974Sixer Member

    Eureka, Tx
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    Jan 30, 2009
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    154
    In adding a fan clutch to a 1974 model with the 258 six that didn't have a factory fan clutch, how far with the addition of a fan clutch move the fan towards the radiator?
     
  6. Jun 29, 2010
    autotech1984

    autotech1984 Member

    Tomball Tx.
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    Oct 4, 2007
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    It gets kinda close probably a little more than 1/2 inch I put one on my 72 a few years ago when I did the power steering conversion. I could give an exact measurement when I get home this evening.
     
  7. Jun 29, 2010
    Rick

    Rick Member

    Hanson,Ma.
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    Oct 19, 2006
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    I'd be interested in the clearances as well. Sounds like something I'd be interested in doing for my '73 258 c.i.
     
  8. Jun 29, 2010
    1974Sixer

    1974Sixer Member

    Eureka, Tx
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    Jan 30, 2009
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    Cutting it pretty tight. I'm not so concerned with an exact measurement other than just curiosity to this point.

    I'd like to know if you've had any problems with the reduced clearance though.

    jzeber, are you telling me the clutch stops the fan due to the internal temp drop due to the water being splashed up on the clutch or are is the fan clutch designed to give way to the resistance of the water on the blades? Sounds like it would still be a gamble if you didn't do as you said and "ease" into the water.
     
    Last edited: Jun 29, 2010
  9. Jun 29, 2010
    autotech1984

    autotech1984 Member

    Tomball Tx.
    Joined:
    Oct 4, 2007
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    I just measured mine and it is just a little over 1/2 inch between the fan clutch and the radiator on my 72 with a 258. You have to use a very short fan clutch I used a Hayden part# 2765 from my F.L.A.P.S. I should mention that I am using a later model water pump because I moved my alternator to the passenger side so that I could mount my P/S pump but it think it is the same height that my 72-75 water pump was. You can buy the fan blade from 4wheel drive hardware or quadratec. A fan clutch is a fluid coupling that is filled with a thick oil so it never is completely locked, the bimetallic spring that is located on the front rotates a small shaft as it expands which is connected to a disk inside the clutch that has holes in it that allow or restrict the flow of oil inside the clutch, however if your fan blades encounter deep water with your engine at 6000 rpm it would probably still do some damage even with a fan clutch.
     
  10. Jul 2, 2010
    clarkent

    clarkent Member

    Griswold, CT
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    Ok good info here.. So I guess the next question is where to get the clutch.
     
  11. Jul 2, 2010
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    It gives way to resistance not temp.
     
  12. Jul 2, 2010
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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    Picked up a whole assembly at the junk yard for $15. It is too long so I am going to look into the shorter one mentioned.
     
  13. Jul 4, 2010
    autotech1984

    autotech1984 Member

    Tomball Tx.
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    Oct 4, 2007
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    Just about any parts house should be able to get it for you, just give them the Hayden part# 2765. I don't know what vehicle that clutch is supposed to fit I just looked through Oreileys catalog at the dimensions for the fan clutches until I found one that would fit. 72 CJs didn't come with a fan clutch and the one that the parts house came up with for a 75 would not work. The one that I used came with a bushing that I had to slip over the water pump pilot.
     
  14. Jul 4, 2010
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    '72 CJ-5 V8s have a fan clutch - only the 6s do not. Just for anyone that's thinking about the fan clutch for their V8 CJ. :flag:
     
  15. Jul 4, 2010
    jzeber

    jzeber Well-Known Member 2022 Sponsor

    Morgan Hill, Ca
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  16. Jul 14, 2010
    Rick

    Rick Member

    Hanson,Ma.
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    Just wondering, are there 2 different snout lengths on the 258 water pump, ( the shaft for the fan)? I seem to have a deeper pulley than some I've seen and would like to get a shorter pump shaft, if possible, to swap on a clutch or electric fan. Right now I only have 2 inches from the fan mounting surface on the pulley to the radiator. This would be for a 1973 vintage engine.
    Thanks
     
    Last edited: Jul 14, 2010
  17. Jul 14, 2010
    autotech1984

    autotech1984 Member

    Tomball Tx.
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    Oct 4, 2007
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    The fan clutch on mine measures approx. 2 1/2 inches from the flange that contacts the water pump pulley to the front of the clutch. The distance from the water pump pulley to the radiator is 3 1/4 inches. I have a stock radiator.
     
  18. Oct 15, 2018
    tripilio

    tripilio Proud American!

    Miami
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    Aug 12, 2018
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    I am thinking about putting one in my F134 for my 62 cj5. I am in Miami, so, very hot! Any suggestions or alternative idea? Thanks!
     
  19. Oct 16, 2018
    jpflat2a

    jpflat2a what's that noise?

    Hermosa, SD
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    I can't think of any good reason/purpose to install a fan clutch on an F4 engine.
     
  20. Oct 19, 2018
    zila

    zila I throw poop

    Rock Springs,...
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    Late to the party but my 75 came with a fan clutch.. I assume the 74 is the same setup and the fan clutch will have plenty of clearance. I have the stock 304
     
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