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Flex Fan Q??

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by ChevyCaGal, Oct 21, 2001.

  1. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Hi... I was going to buy a flex fan. I was wondering what size to get? Should I buy the same size that is in there now with my fan or not? The guy at the parts place suggested I buy one a bit smaller because of how the blades work on it. Is he right or a moron? Thanks....

    &lt;&gt;&lt;<a target="_blank" href=http://www.chevycagal.homestead.com/steph.html>Steph's Webpage</a>&gt;&lt;&gt;
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  2. chevyracing

    chevyracing 1/2 ton status

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    Re: Flex Fan Q?? *DELETED*

    Post deleted by chevyracing
     
  3. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    He was talking about height though not width in the fit and that's what I am wondering...?

    &lt;&gt;&lt;<a target="_blank" href=http://www.chevycagal.homestead.com/steph.html>Steph's Webpage</a>&gt;&lt;&gt;
    Suck Fumes Ford Boy
    I keep trying to lose weight, but it always finds me!
     
  4. pcorssmit

    pcorssmit 1/2 ton status

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    I would avoid flex fans altogether and just keep the stock fan. In my experience they don't do a very good job of cooling. I have one friend in particular that tried several different models in a CJ w/a 360 and auto trans and still had to run an electric pusher fan to keep it cool. He swapped on an OE clutch fan and pulled off the electric, no problems since.

    Pete

    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     
  5. chevyracing

    chevyracing 1/2 ton status

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    Re: Flex Fan Q?? *DELETED*

    Well, you want to get one that will fit inside your shroud for sure, so keep that in mind. You also need to make sure you have the right spacing between your radiator and the fan hub so you don't have an owie there. If you are too close you can change the spacer between the waterpump and hub. I have never seen one that was too close to the point it would get into the radiator. So basically, my opinion is the guy was full of excretion.

    John

    I had to fix some things, that is why I deleted this.....sorry

    Like to go sloppin' 'round in da mud in a rapid fashion....=) [​IMG]

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  6. DesertDueler

    DesertDueler 1/2 ton status

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    Stay away from the flex fan. My buddy just put one on his 66 mustang with a stock 289 about 2 months ago. In order to keep t cool he has to do 90 on the freeway, and at stop lights he has to rev it up to 3500 rpms to keep it from overheating. He cant drive in traffic either. BTW the fan is the same size as the stock one. He never had any problems with it until he put the fan on.

    86Jimmy 4"&35"MTRs,87 burb 4"&35"MT,69Firebird w/525 hp,and 70GTO live in PHX,AZ<a target="_blank" href=http://www.geocities.com/modifierperformance>My vehicles</a>
     
  7. BigTex

    BigTex 1/2 ton status

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    It is not necessary to stay away from the flex fan. I have one in mine and it works just fine. Used to have one in a 1969 big block Camaro and it worked just fine, too.

    As far as the size goes, I don't see what his reasoning behind the smaller size is. The blades straighten up when the speed of the fan increases. In other words, the blades don't get larger. I just measured my fan for you and it measures 17 1/2". Hope this helps.

    <font color=red>"SETTING OFF ALARMS IN A CITY NEAR YOU!"</font color=red>

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  8. ChevyCaGal

    ChevyCaGal 3/4 ton status

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    Thanks... that's all I was wondering was about the height. I couldn't tell for sure what size I had and I came up with about the same as you did so it's most likely right. I know some hate flex fans... others like em. I like em and wanna try one out... [​IMG]

    &lt;&gt;&lt;<a target="_blank" href=http://www.chevycagal.homestead.com/steph.html>Steph's Webpage</a>&gt;&lt;&gt;
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  9. twenty_below0

    twenty_below0 1/2 ton status

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    I have a very nice flex if your interested and it will fit in the shroud and guarantee to keep yours cool!! It is a quality flex-a-lite fan and was only ran for about 4,000 miles....removed for an electric, pm me and we can talk if you'd like! Mike
     
  10. coopertwpk

    coopertwpk 1/2 ton status

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    Youll be wasting your money Steph and dont plan on using your A/C after you install it it will no longer pull enough air on the HWY to keep up ,if you want one my buddy thomas has one that came off his dually it kept over heating ,also in water crossings they will distort and fold into your motor or radiator .Think about it before you change.also all early trucks w/o a/c came from the factory with them until chevy found out over long periods they fatigue and explode I can get you the letter from work.

    88k5 silverado w4"lift <font color=orange>d44 and corp14ff</font color=orange> with 4.11
     
  11. wakedog

    wakedog 1/2 ton status

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    I just put a 19" Flex a lite flex fan on to my truck, it works great, its kept my truck at least 15 degrees cooler.

    <a target="_blank" href=http://www.bigredjimmy.iwarp.com>http://www.bigredjimmy.iwarp.com</a>
     
  12. Itali83

    Itali83 1/2 ton status

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    I have a flex fan on my truck, always have had one, NEVER had a cooling problem. even sitting in traffic for over an hour in 95 degree weather, the people that have probs with the flex fans must not have them set up right. The only down fall I can see is that they may rob a FEW horse power, and they DO make more noise, but cooling they work fine if not better for me.
    Ben 87 Jimmy
    <font color=blue>Rust=Bad</font color=blue>
     
  13. lugnut

    lugnut 1/2 ton status

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    After geting the rad. flushed,changing thermostats a couple times and finnly instaling a new rad. I put a flex-fan on. Now I can sit in heavy trafic with frount+rear air on max or pull 7500 pound camper at 70 mph without problems.It stays 15 to 20 degres cooler.

    78 sub 454. Big as a tank and hard on my bank.
     
  14. Bubba Ray Boudreaux

    Bubba Ray Boudreaux 1 ton status

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    I've been running run for 4 years. Went into a speed shop, said this is what I have and they gave me the right one. Cooling benefits, NONE!!!!! Didn't improve nor get worse. Sound? Awesome!!! Nothing like going into 1st gear and winding the engine up, scares people, hehehe. Never had problems with A/C, because the fan has nothing to do with the A/C, it's airflow over the condenser, which is in front of the radiator. One warning besides the exploding warning, the blades are damn sharp. Plenty of times I've bearely touched a blade and come out bleeding like a stuck pig. Never cross water that might get up into the engine bay cause the fan can come off and eat radiator. Final advice, got electric. That's what I will do eventually.

    Bubba Ray Boudreaux,
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  15. Pugsley

    Pugsley 1/2 ton status

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    Good point - I'm fixing to go electric just as soon as I can let this thing have a few days' rest. Add a Flow Kooler water pump, new thermostat, and all that good stuff while I'm at it.

    Of the 5 toughest dogs in the neighborhood, my cat's ranked #3
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  16. therover87

    therover87 1/2 ton status

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    whats the part # for the flex a lite ?
     
  17. dragricinMT

    dragricinMT 1/2 ton status

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    Heres my 2 cents worth.
    Running a flex with the right spacer will not cause a vehicle to overheat. A fan clutch is not always engaged. It operates off the temp of the engine and locks up at high heat. Most often it has a drag{spins slower than acctual rpm}. A flex fan spins at the same rpm as engine. Around town driving it pulls more air through the radiator than a fan clutch system. At high speeds both are close to equal. A stock fan set up for a fan clutch does not pull as much air as a flex at slow speeds unless it is fully engaged which means its running hot. So how do flex fans s***? JMO.




    78-K5 4"Lift 35"Tires 400SB TH350 NP205
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  18. Triaged

    Triaged 1/2 ton status

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    I had probs w/ my flex fan trying to get up deep sand hill. I was in 1st gear and lo range. The engine was at high rpm (so the blades were flat) and going around 5mph. After 4 attempts at the hill I had to sit with the engine reving for a few min. to get it to cool down. This is not something you have to worry about every day but nun the less it was a pain.

    '71 Blazer CST w/ a 400sbc, 4" lift, 36" Supper Swampers, and alot of rust
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  19. dyeager535

    dyeager535 1 ton status Premium Member

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    Flex fans suck because they don't stall, as clutched fans do. What do flex fans do at higher speed? They flatten out. Well, lets see...curved blades, now flat....hmm, flat blades=plate. Air does not flow through a plate. THATS how flex fans suck.

    Yes, clutch fans steal about 5 whopping horsepower. There are a couple of different clutches if you care to adjust them.

    If you want to get away from stock, go electric. You can almost eliminate airflow loss through engine at speed (they shut off) and sitting around town, engine speed, unlike stock or flex, you don't have to raise the engine RPM's to increase airflow. They don't "rob" as much HP as stock or Flex, just a little more draw off the alternator.

    Besides, with an electric, you can eliminate the fan shroud. And not have to worry about fan blades sticking through the hood. (anyone still go the link to that flex fan sticking through the truck hood?)




    Dorian
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