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Technical 322 Nailhead Dual Quad questions

Discussion in 'The Hokey Ass Message Board' started by Beemon, Mar 25, 2016.

  1. Beemon
    Joined: Aug 24, 2013
    Posts: 24

    Beemon
    Member

    I have a 1956 Buick Century 322 Nailhead with a stock drive train and I want to put in dual quads. I've got a lot of SBC guys telling me its not a good idea, too much fuel consumption, no power, bad gas mileage. I'm in the process of acquiring a dual quad intake and am wondering if it's all true or not. I've done some research and 322's supposedly love up to 600CFM and the lowest dual quad setup I've seen is dual 500CFM. The manifold is late AFB bolt pattern, so I'd have to get a pair of Edelbrocks or equivalent. Is this really too much CFM? Will this be okay for the stock drive train? I love dual quad setups and just want some hotrod flair, but not at the expense of poor gas mileage, etc.
     
  2. k9racer
    Joined: Jan 20, 2003
    Posts: 3,091

    k9racer
    Member

    Nail heads have 3 different Intakes. make sure yours is for the engine you choose Their have been a lot of 322 with dual 4 carbs. Most 322 had the cast iron /alum wc searies carbs. 364 1nd 425 had the afb carbs,
     
  3. Beemon
    Joined: Aug 24, 2013
    Posts: 24

    Beemon
    Member

    This intake is a Weiand late model intake for the 264-322 for AFB carbs, not WCFB. I've just been hearing that dual 500CFM might be too much but elsewhere say it's okay. Don't want to drop the $$$ on something that won't work for a stock Buick
     
  4. k9racer
    Joined: Jan 20, 2003
    Posts: 3,091

    k9racer
    Member

    you could adjust the linkage so that the carbs only partial open up. Maybe 1/2 throttle. You could put restrictors between the carb's and intake, Last only run on the primary front 2 barrells of the carb's, Or just work with the carbs until they run and drive correctly.
     

  5. Beemon
    Joined: Aug 24, 2013
    Posts: 24

    Beemon
    Member

    bump

    want some nailhead guys in here

    Was suggested to me to find some matched small bolt rochesters, strombergs or wcfbs from 1954-56 buicks for best results and run solid linkage. have a lead on another rochester, same tag. Should I go this route? seller had a wcfb and an afb (what i bought) manifold
     
    Last edited: Mar 28, 2016
  6. talk to russ martin @www.nailheadbuick.com. he is the nailhead guru.
     
  7. Beemon
    Joined: Aug 24, 2013
    Posts: 24

    Beemon
    Member

    he said dual 500cfm edelbrock avs on progressive, but i just wanted some other opinions. I don't really like the idea of progressive starving front cylinders. also talked to edelbrock, they're idiots.
     
  8. aarestor
    Joined: Feb 22, 2011
    Posts: 278

    aarestor
    Member

    I do not have a lot of time on mine but it works very well. I am running two 500 cf. Edlebrocks. I do not know what the fuel milage will be but it is not important to me.
     

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  9. jimmy six
    Joined: Mar 21, 2006
    Posts: 14,796

    jimmy six
    ALLIANCE MEMBER

    image.jpeg I'm not sure how the internals of the manifold you are going to use is ported/cast. I run dual quads on a 292 Ford Y-block and lost maybe 1mpg. I did a lot of playing around with an air hose and taping off ports to make sure I could run on just the rear carb for normal driving and I could. 245/270 hp Corvettes ran like this from 1956 thru 1961 and do today, Edelbrock sells the linkage kit to run progressive. The only thing I found was when the engine was cold I had to press the throttle all the way so some fuel would pump the front ports. Only the rear choke is connected. I do use Carter WCFB's because the manifold carb bases are the small ones. You can see the "progressive" linkage in the photo. I made it and at wide open throttle both are wide open.
    There are Carter AFB's that are rated at 400cfm but they are pretty hard to find and there is a guy on the internet makes a device you place on a 600 to make it a 500 cfm. I see no reason you could not add them to a 500 to make it a near 400 cfm. Good luck
     
  10. Black Panther
    Joined: Jan 6, 2010
    Posts: 2,133

    Black Panther
    Member
    from SoCal

    Beemon....GM ran dual quads factory on many cars. Try to copy that setup. I had several 2x4 425 nailheads in Rivieras that ran just fine off the back carb only. In that setup also in 409s they used a front carb that didn't have an idle circuit...in other words the front carb operated like the outboard carbs in a real 3x2 setup. With the proper front carb...you won't lose vacuum and it only comes to life after 75% or so of the throttle is tromped down...I'm a proponent of the progressive setup..especially in a small inch motor like yours...
     
    Last edited: Mar 28, 2016
  11. Beemon
    Joined: Aug 24, 2013
    Posts: 24

    Beemon
    Member

    Is that a 322? Looks nice with the chrome valve covers!

    If posed the choice between 2 new edelbrock and 2 old rochester...
     
  12. aarestor
    Joined: Feb 22, 2011
    Posts: 278

    aarestor
    Member

    Yes it is a 1956 322 bored .040. I had the valve covers plated.
     
  13. wex65
    Joined: Dec 19, 2012
    Posts: 1,118

    wex65
    Member
    from WV

    Call Tony over at Ross Racing Engine. Specializes not only in older motors including nailheads but in getting the most out of them. this is my '55 322 he put together.

    Wouldn't go anywhere else.

    Oh, and although gas mileage was never a requirement for me this gives 19-20 MPG and performed flawlessly on the 3k mile round trip to the Lone Start Roundup this past week.

    IMG_3409.JPG
     
    Pinstriper40, Beemon and Fedman like this.
  14. Well lets see 1000 CFM sounds like a lot, my 355 runs well on 600-700 CFM.

    Ok now lets analyze the situation, two 500 CFM carbs, running progressive you will seldom be into the second carb, so most of the time you are running on 500 CFM or less. You secondaries are not mechanical so they will only come open if you pull enough vacuum to open them. Again seldom if ever will your 322 draw a deep enough breath to open the secondaries very far if at all so that brings us back to running on 500 CFM but not all the time.

    I personally would think that you could get away with smaller carbs but if you cannot get smaller carbs that fit the intake you will be running what you can get and I doubt that you will ever see 100 CFM anyway.
     
  15. Beemon
    Joined: Aug 24, 2013
    Posts: 24

    Beemon
    Member

    I picked up a second Rochester 4GC that's identical to my stock one, and I was advised to go with solid linkage, so I'll be running that pair and see how it performs for me.
     
  16. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,657

    Rusty O'Toole
    Member

    No way can you use that much carb unless your motor is hopped up to the max. You will be way better off with a single 4 barrel. Better performance, better mileage, simpler, cheaper, less hassles.

    Buick did offer a dual 4 barrel option in the early sixties on some Rivieras. Similar engine to yours but 100 cu in bigger and with a number of other breathing improvements. The 2X4 turned out to be too much even for that motor and most were replaced by a single 4 barrel.
     

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