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Electric Fan Question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by getsome, Aug 28, 2000.

  1. getsome

    getsome 1/2 ton status

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    This week I'm going to put a electric fan on my Jimmy but I have some questions first: Should I get a single fan or a dubble fan? Second: Pusher or puller? I was thinking that twin 10" pullers would be better but I'm not sure. Would a single 16" be enough on a almost stock 350? It gets hot sitting in traffic and the rad is three days old. My Jimmy is a 84 350ci, 700r4, 35" BFG's, and 6" lift. Any help or input would be a help.

    Getsome
     
  2. Emmettology 101

    Emmettology 101 3/4 ton status

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    I am running one 16" fan on the front of the radiator and it is not enough. I would run tow of the largest fans you could fit side by side on the rear a pulers and one in the front center as a pusher. That is what I will be doing.

    My cooling system isn't up to snuff so that could be the reason one 16" pusher isn't enough.

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  3. getsome

    getsome 1/2 ton status

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    My electrical skills are very limited. Goes back to a theory I had about weather a engine would still run if you pulled the coil wire off. I don't twitch much now but it's been a few years. Maybe four pullers?

    Getsome
     
  4. Emmettology 101

    Emmettology 101 3/4 ton status

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    I would go with two on the rear(engine side of rad)set up as pullers.. Get them large enough to cover most of the core from top to bottom and side to side.
    That is what Perma cool told me.

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  5. Jason73K5

    Jason73K5 1/2 ton status

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    I run a 16" puller controlled by a thermal switch. It works great here in the heat of central california.
     
  6. Scoobydoo

    Scoobydoo 1/2 ton status

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    NO electric fan or number of electric fans, will work as well as a regular clutch fan, especially for towing!
    Not only will it not cool as well, but you are pulling power from your alternator that could be necessary for lights or a winch or ?.
    If your alternator ever goes out, you can usually drive home or to the shop on your battery alone, but NOT if it is also running these fans!
     
  7. blazer72

    blazer72 1/2 ton status

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    I run 2 14 inch pullers mounted togeather and 2 12 in front of the a/c coil at highway speeds any time the a/c is on all 4 fans are on, with the a/c off only the 2 14 ichers are used. at highways speeds and with the 160 deg stat. the fans cycles on and off the colders the air is the longer they stay off. The fan controler is set to turn on at 180 and off at 170. All the fans are flexlite and the controler is from Hyden. And yes I wish I still had the old motor driven fan still but with bodys lifts and all its gone and not comeing back!

    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  8. Emmettology 101

    Emmettology 101 3/4 ton status

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    Hey Ken,

    The controller you have for your fans, is the sensor the type that screws into the block or intake, or is it one of those styles that zip ties to the radiator hose?

    Also, does this turn on and off your fans the way you said or do you control them by switches?(between 2 fans working and 4 fans working etc..)
    Thanks

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; http://emmett.coloradok5.com
     
  9. realsquash

    realsquash 1/2 ton status

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    I haven't read anyone's responses yet, so sorry if I'm repeating...

    An almost stock 350 should not overheat sitting in traffic. You have other problems if that is the case. Electric fans do *not* move more air than your stock mechanical fan by nature. Are you running a fan shroud? If not, that is your problem.

    Squash
    http://www.trailrunners4x4.org/users/realsquash
     
  10. sosamantx

    sosamantx 1/2 ton status

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    How big is the radiator (2 or 3 row)? I aree, your Jimmy shouldn't be getting that hot, especially in Colorado. How hot does it get there anyway? How old is your thermostat, and does the water flow through the radiator seem to be suffiecient? I would keep the stock fan with the clutch (you can get an aftermarket clutch, but I don't know what it would do), and get an electric fan(s) as an aid (pusher), and probably wire them with a toggle switch. You could also have the fan(s) setup to come on at a certain temperature (you could put a switch here as well). You could go to http://www.flex-a-lite.com/, or http://www.permacool.com/ and get the dimensions, cfm ratings, and current draw (amps). Heck my 74 Nova was marginally cooling here in Texas (180-190 moving, and 190-210 sitting in traffic), so I added an Edelbrock hi flow waterpump, and a Robert shaw 160 degree thermostat which made a he!! of a difference. Now I just want to add an electric fan as an aid (pusher). I only have a 3 row radiator on the car with a sb350 (not really stock), and there is very little room for the air to circulate under the hood. We have been in the upper 90's and 100's not counting the heat index, and it runs about 170-180 degrees on the road and about 190-200 max. in traffic. This is why I want an electric fan. I would get a better waterpump as well. - Steve

    Steve Sosa a.k.a. "sosaman"
    http://sosaman.home.texas.net/carpics.html
     
  11. blazer72

    blazer72 1/2 ton status

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    the controler has an input for the a/c and 2 outputs one for the main fan one for aux fan. The senser is in the radator not the motor. It sticks in the coils is all. The aux fan come on when the temp goes over 200 deg. or when the a/c is all the fans just come on.

    I understand the jeep thing I drive a BLAZER!!

    Ken
     
  12. getsome

    getsome 1/2 ton status

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    The rad is a new (not rebuilt) 3core with a 180 deg thermostat. I bought a upper and lower shroud from LMC and installed the upper part. It still got hot. I ran it up to Nebraska a few weeks ago with the old rad and upper shroud and even driving on the highway it was getting hot. By hot I meen 205 and above. When it gets much over 205 it starts to run rough and acting like it's going to vapor lock. Do to some custom body work done by the previos owner(concrete divider) the rad support sits slightly to the left and rubs the shroud and makes nasty noises. After pre-installing the lower shroud I new that there was no way it was going to work right. My 1970 Cutlass has a 350 and a 3row rad and it never gets hot. By installing electric fans I would fix the problem of the frontend tweek and the drag on the engine caused by the fan. Thats my theory. As I've posted befor my theorys don't always work.

    Getsome
     
  13. jarheadk5

    jarheadk5 1/2 ton status

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    getsome, sounds like you've got a couple problems:

    1. I think your gauge is WAY off. If it's the factory gauge, it's probably shot to hell. At 205 deg. actual coolant temp, you shouldn't be getting pinging, hesitation, etc.

    2. You may have a water pump or thermostat problem. As big as the grille opening is for air, highway speed should provide plenty of airflow (without A/C on) with the engine fan and only the upper shroud. That's how my Blazer is set up, and I drive mostly highway with no problems. Of course, I don't have the "creative bodywork" you have.

    You could try adding some Redline Water Wetter to help keep things cool, about 3 oz. per gallon of coolant.

    Hope this helps!

    [​IMG] Semper Maintenance!
     
  14. ColAdo82K5

    ColAdo82K5 1/2 ton status

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    Hey all,
    I run a pretty stock 305 in my blazer and it runs 210 degrees on highway or 210 if i run it in traffic long enough. It's a factory gauge and I've replaced the water pump recently. Is this temp way off ? too hot i'm guessing. The truck runs great even at that temp. help !
    Blake
     
  15. sosamantx

    sosamantx 1/2 ton status

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    Hey <font color=green>Getsome</font color=green>, are you running factory guages or aftermarket? If aftermarket where is the sending unit, on the head or on the intake? The intake would be better. <font color=green>ColAdo</font color=green>, I would replace the temperature sending unit and see if it makes a difference on the guage. Fyi, I would keep the mechanical fan and add electric fans as an aid, I don't think you will notice a difference in horsepower, or mpg (if it is it would be minimal). - Steve

    <font color=blue>Steve Sosa a.k.a. "sosaman"</font color=blue>
    http://sosaman.home.texas.net/carpics.html
     
  16. 76GMCJimmyinAZ

    76GMCJimmyinAZ Registered Member

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    My 76 has a 30K crate motor (hopefully not too gunked up inside yet), a 3 row rad that was replaced (new) at same time as motor, stock fan with no clutch, stock fan shroud, sensor plugs into left side of motor, and at 110-115 degrees here in summer, A/C on as friggin' high as it will go, and even pulling the boat, my stock gauge never gets above 1/2 scale. I tend to believe it because it's never even acted hot.... Just my .02. There must be something else going on with yours.... I've considered converting to electric fans (because mine is quite noisy), but decided that since my cooling situation is as good as it is, with my luck if I change it, I'll start having problems!!

    GUZZLES GAS BUT IT'S FREE AND CLEAR!!!
     
  17. getsome

    getsome 1/2 ton status

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    All the guages are stock. They seem to be reading correctly. I think that it get it's reading from the block just under the drivers side head. I have looked today at some Auto meter guages that have oil pressure, volt, and water temp. Auto zone has a three guage set for $56, Summit for $59, and Carparts for $69. I'd hate to spend 56 bucks to replace something that works. Testing the guage is beyond my electrical ability. The water pump looks good, no leaks, not singing, dry as a bone. The hoses are new, and I even cleaned the radiator looking thing in front befor I installed the new radiator. It could be the thermostate and the reason that I didn't replace it is I remember what a pain in the ass it was to get one on my truck to seal correctly. I agree with Jar that something else is wrong but as to what I don't know. Maybe tomarrow I'll bite the bullet and replace the thermostate.

    Getsome
     
  18. jarheadk5

    jarheadk5 1/2 ton status

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    I'm not a carburetor guy, but there's plenty here. Could this be a carb-tuning problem (too lean maybe)? If this is possible, you need to fix that before you melt a piston. Like I said though, I'm no carb expert.

    [​IMG] Semper Maintenance!
     
  19. det45

    det45 1/2 ton status

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    In my 89 K5 I run the original clutch fan along with a 16" puller fan mounted on the inboard side ot the radiator. (There's plenty of room there between fans.) The factory fan of course pulls air in as doe's the 16" electic puller. My engine runs at 180 degrees all day long with AC on. Before I put the elect fan in it would creep up to 210 degrees in traffic with AC on. Now it stays at 180 degrees with AC on. I live in south texas and it gets hot here daily. (around 100 degrees plus in the summer) My 16" fan is connected to the ignition and is on all of the time as long as the truck is running. I also have a bypass elect switch to shut off the elect fan in the winter months where it is not needed. This set up works well with my K5 in south texas and my engine is the stock 5.7 liter TBI 350.
     
  20. getsome

    getsome 1/2 ton status

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    It's been a strange summer here in Colorado. For the last three months it's been 90 or above. I know cry me a river but three months over 90 is way above what it should be. I lived in Tucson for three years and grew to love the heat and the monsoons. I just changed out my rods and jets on my carb because I thought about what Jarhead said and I did choke the hell out of it so that it would pass emissions. It should run a little fatter now. I'll see what happens tomorrow when I take the little bogger to school.

    Getsome
     

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