demon carb identification

Fuel and Air Systems

  1. All4rocks

    All4rocks Well-Known Member

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    anyone help me identify this Demon carb? i googled it but still cant figure it out. I believe the guy told me it was an 850. It came on a 472" Hemi i have. I dont need it anymore.

    IMG_1613.jpg IMG_1611.jpg IMG_1610.jpg IMG_1615.jpg
     
  2. beanhead

    beanhead Well-Known Member

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    Looks like the old pre-Holley Mighty Demon. It should not have adjustable emulsion bleeds in the metering blocks; I think that feature was on on the Race Demon and higher models.
    Looks like '56' by the secondary choke horn, which was the 850. (1.56 venturi).
    You can verify the rated cfm size by measuring a venturi and a throttle blade.
     
    Last edited: Jun 7, 2021
  3. oldkimmer

    oldkimmer FBBO Gold Member FBBO Gold Member

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    What’s the numbers on it? Kim
     
  4. All4rocks

    All4rocks Well-Known Member

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    The 56 stamped on the secondary choke horn and the 175 stamped into the bottom of the blades is all there is.
     
  5. beanhead

    beanhead Well-Known Member

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    56= 1.56 venturi
    175= 1.75 throttle plates
    That's Demon's 850 cfm
     
  6. All4rocks

    All4rocks Well-Known Member

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    So it’s an aluminum mighty demon with mechanical secondary’s?
     
  7. beanhead

    beanhead Well-Known Member

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    To really be sure it's a Mighty you'd have to pull a bowl and metering block off and see if there are replaceable jets in the emulsion holes. The Race Demon had these jets but the Mighty did not....and that's of course assuming the blocks were never swapped out. Mighty Demons also were not set up for replaceable booster nozzles like the Race Demons, again you can tell from the inside. We know it's at least a Mighty Demon because there's no choke horn on the primary side.
    The metering blocks and baseplates were billet aluminum but the body and bowls on the older ones were a cast zinc alloy. I have an 850 Speed Demon (from the Barry Grant era)and it's considerably heavier than the aluminum body Quick Fuel that I have. It's too bad the baseplate and linkages are in rough shape on yours because they don't make replacements anymore....you have to use a Holley baseplate and they aren't 100% identical.
     
    • Thanks! Thanks! x 1
    • All4rocks

      All4rocks Well-Known Member

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      Here’s a pic of inside the metering block.

      83041B75-CD59-410A-A0AD-186A01CD5569.jpeg 1CC055FA-11F1-4AE7-84B3-9039E8709F38.jpeg
       
    • All4rocks

      All4rocks Well-Known Member

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      So is this a race demon or a mighty demon?
       
    • beanhead

      beanhead Well-Known Member

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      If the main body has removable boosters like this, it's the Race Demon.

      Screenshot 2021-06-08 at 21-07-27 113_0205_demon5_z jpg (WEBP Image, 770 × 578 pixels).png
       
    • All4rocks

      All4rocks Well-Known Member

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      thanks beanhead. ill go check.
       
    • All4rocks

      All4rocks Well-Known Member

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      It looks to have t
      image.jpg
       
    • beanhead

      beanhead Well-Known Member

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      Welp...that be the Race Demon.
      Unfortunately, people had a love/hate affair with the Demons then (mostly hate:rolleyes:)..Many people refused to use them; yet some (like myself) seemed to get good results. I never got one that was full of shavings, had un-drilled passages, wouldn't take a tune, etc but lots of guys did and as such the BG stuff never really blossomed IMO.
      The pisser with the older BG carbs nowadays is getting proper replacement parts. Holley has about zero interest in providing much support for the original demons beyond just the basic rebuild kits/jets/stuff like that.
      If you call them looking for parts or info they pretty much just tell you to buy a new one....Lame!
       
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