(2) 12" fans versus (1) 16" fan

Small Block Mopar Engine

  1. rklein383

    rklein383 Well-Known Member

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    I didn't realize there were so many experts out there. This site is great!
     
  2. Mopar73340

    Mopar73340 Well-Known Member

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    If your using a 26” radiator probably the best fan is a Mercedes fan from the C class. I use this on my E-body 26” radiator and it will cool it running at 25% fan speed @ idle. The most I’ve seen it go is 50%. The drawback is it needs a controller and I’m not sure about the space on an A-body.
    There is an extensive write up on Moparts if anyone is interested.

    D576F942-5845-4A73-9BA6-E4BDD1678D35.jpeg
     
  3. Matts440

    Matts440 Well-Known Member

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    I agree when going above the regular requirements, but the alt I have is a mopar looking one and also converted to 1 wire so stock wiring is out, but they have lower amp ratings as well, just have to compensate for the draw when adding to the charging system. Yes I have rewired the whole car with new wire, my setup should work for my setup still fabricating a few things still. Again I agree with what your saying, just putting how I did things out there.
    * wow just looked at the black magic dual fans they pull 28amps, my 4 only pull together 12amps. Wonder if anyone's done a true comparison from 4 low amp to two high amp with a shroud test?
     
    Last edited: Mar 23, 2020
  4. Wyrmrider

    Wyrmrider FABO Gold Member FABO Gold Member

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    thanks Fire Guy
    WE did extensive for Chrysler on the grades of the California desert
    The grapevine, the "Baker Grade" The 29 Palms hill
    Shrouds work
    Spoilers work on the raising the pressure in front lowering behind the radiator problem
    and we found that slow pulls with a tailwind the hot air was just going around and around under the core support
    IMHO there is not a electric that will work with a big motor and a loaded trailer
    I use a 9 blade fan on my truck which is a FSB upgrade from the oem 7 blade high pitch fan
    GM has an 11 blade (on my motorhome) which I need to try this summer
    I have a two fan pusher off a Merceedez or bmw - had to trim the grille
    really helps in stop and go and makes the AC work better
    I use a 73 400 jn the speedo line controller to turn the fans off at 28 mph (they controlled the vac advance)
    on radiators frontal are is best but do what you have to do
    sometimes you can use a big block core support
    no flex fans or plastic
     
  5. famous bob

    famous bob mopar misfit FABO Gold Member

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  6. famous bob

    famous bob mopar misfit FABO Gold Member

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    A 1/2'' thick elec fan shroud , did block air in mine , the air flow isnt great with one that thin over all the rad.. Wouldnt work for me , but my engine produces a lot of heat !
     
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    • flyfish

      flyfish C8H18+N2O = :-D

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      I use a 2007 Chevy HHR fan to cool the 408 in my Barracuda (low 10 second street car). They are cheap (about 50 bucks), fully shrouded, pull a ton of air...works great. I have had one on my car for about 7 years now, no cooling issues. Just had to trim a little plastic off the fan motor with a dremil tool...then it dropped right in. It fits 22" radiators perfectly.
      upload_2020-3-24_8-45-52.png
       
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      • 72bluNblu

        72bluNblu FABO Gold Member FABO Gold Member

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        Looks awesome! I’d like to see that write up, do you have a link?

        The only drawback is the single motor arrangement puts the fan motor right in front of the water pump pulley, so it would have to be pretty thin. That’s the nice part about dual fans, keeps the thickest part of the fan assembly away from the tightest clearance. But if it’s thin enough at the back of the motor that would be a great set up.

        Yes, but not everyone fully rewires their car for this. I haven’t. I run an amp gauge bypass and have my fans run off of relays but it’s all tied back to the stock harness.

        I’m not sure your comparing apples to apples with the fans. Fans can be rated at start up or at steady state. The start up amperage is much higher than what they pull when they’re already running. With a 4 amp rating I seriously doubt that’s the start up amperage.

        You guys are just silly. They make electric airplanes now, think about that for a second.

        If a mechanical fan can cool a particular engine, so will an electric fan. All you have to do is match the cfm output of the mechanical fan, and all that comes down to is blade and shroud design and the amperage to the motor. The mechanical fan and shroud can already do it, so really it’s just matching the power and speed requirements with the electric motor.

        Now, there might not be an off the shelf electric fan that will meet the requirements of your particular system because of the dimensions and power requirements, but that’s not the same as saying an electric fan can’t cool it.

        Also a nice set up! The other one that works for 22” radiators is the older Ford Taurus set up, I forget the year range. But I think the HHR fan is a little thinner?
         
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        • TurboGLH

          TurboGLH Well-Known Member

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          I went with a Chevy HHR fan for my 408 build as well, but I wasn't satisfied with the mounting options. I wanted to use the mounts for the factory shroud, so I designed and 3d printed prototypes.

          IMG_20190913_065455.jpg IMG_20190913_065545.jpg IMG_20190913_195136.jpg IMG_20190913_195219.jpg IMG_20190913_231456.jpg IMG_20190914_162415.jpg
           
        • famous bob

          famous bob mopar misfit FABO Gold Member

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          I `ve tried about 6 diff, elec set ups , even 3 at once , they wouldn`t keep mine cool.
          I dont have room for a contour or hhr fan , and mounting factory shrouds on a crossflow presents another set of problem .
           
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