Please help identify this carb

Discussion in 'Intake Systems , Fuel Systems and Related' started by Tunnel Vision, Nov 9, 2018.

  1. Tunnel Vision

    Tunnel Vision New Member

    I would like to start by saying this website has been the most helpful website I have EVER encountered. I am a long time lurker but reaching out for some help on this one.

    I purchased a SBC tunnel ram from an old timer with two of these carbs and they were advertised as 660 center squirters. I knew by looking at the provided pictures that they were NOT the 660's that I have come to know from research but the price was so good ( and 660's so pricey) that I grabbed the setup and figured I would sell the tunnel ram as I am not building a SBC and run them on my RB Mopar tunnel ram. I am currently thinking it's an old 750 DP with some mods but would like to know as much as possible as I plan to rebuild them and need to know what kits to buy.

    Thanks to everyone in advance for any help you can provide. IMG_9572.JPG IMG_9573.JPG IMG_9574.JPG IMG_9576.JPG IMG_9577.JPG IMG_9579.JPG
     
  2. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Its A Holley Double Pumper at least 750 cfm.
    You need to the Baseplate bore size.
    Then the Upper main body Venturi size .
    Determine approximate Rated CFM flow.
    It could be as high as 950-1150 cfm.

    The Holley list number was on the choke horn. Milled off.

    It's a Racing Holley.
    Has adjustable low and High screw in air bleeds.
    Fine tune in close to EFI performance.

    It's mid to late 1990s vintage I believe.
     
  3. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Somebody milled off the choke in a Bridgeport.

    Lacks smooth radius profile work in modern Holley Hp series and aftermarket Race Holley.
     
  4. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Small time Drag Racer or dirt track guy.
    He was handy.
     
  5. Tunnel Vision

    Tunnel Vision New Member

    Thank you!! Does the throttle plate numbers dictate the bore size? That's what I used to guess on the cfm. I see the primaries are slightly smaller than the secondaries so I will have to measure when I disassemble. I will have to educate myself on "Has adjustable low and High screw in air bleeds."

    Let me ask, why have one accel pump when the linkage to the secondaries is progressive? My brains logic says this is wrong but my brain has been wrong so many times before.
     
  6. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    There are guideline charts to lookup.
    I recall Grumpy has them somewhere here.
    He will be around.
    Post links & usually types in his own 2 cents .
     
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  7. chromebumpers

    chromebumpers solid fixture here in the forum Staff Member

    Hey Brian, why do you think the second pump has been disabled?
     
    Maniacmechanic1 likes this.
  8. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Yes your right.
    Good eyes.
     
  9. Tunnel Vision

    Tunnel Vision New Member

    Assuming it must have the single pump feed the complete center 'squirter'. Could it be high volume like I would expect the 660 to be? Still why have it feed the secondary venturies if they aren't even opening due to the progressive linkage running the secondaries ?
     
  10. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    The working accelerator pump is a 50CC unit.
    From the Holley Dominator 4bbl.

    The other disabled is a 30 cc accelerator pump.
    Holley double pumpers usually come with twin 30cc .

    The Holley you have was purpose built for something.
     
  11. Tunnel Vision

    Tunnel Vision New Member

    Great info thanks again. I know this was a drag car setup but I wished I would have asked him more questions on his setup. He only commented he did run it on his car some time back but that it would't fit under his fiberglass hood and he didn't want to change the hood. 1964 Tempest was the car. This guy was probably in his late 70's with a building full of small block stuff.

    I will tear into them to see if anything else leaves me scratching my head.
     
  12. Tunnel Vision

    Tunnel Vision New Member

    I found the base plate to have the standard 1 11/16" bores but I am unable to measure the venturi's with the tools I have. I eyeball them to be around 1.3" at the smallest diameter at the top with my calipers. I think this measurement excludes them from being 750's but maybe converted 650's? Best I could find is that the 650cfm double pumpers shared the base plates with the 750's but it was the venturi's that was different and the 750 had a venturi around 1.38" which these carbs do not.

    I do see the very top of the venturi has been worked very slightly so maybe the old timer was correct when selling them as 660 carbs, just not the 4224 I am familiar with. IMG_9582.JPG
     
  13. Tunnel Vision

    Tunnel Vision New Member

    Also no power valves
     

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