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354 hemi 3x2

Discussion in 'The Hokey Ass Message Board' started by jobbless, Mar 7, 2012.

  1. jobbless
    Joined: Oct 11, 2004
    Posts: 303

    jobbless
    Member

    Well, I traded my 6x2 weiand drag star for a weiand 3x2. First I figured I would be over carburated. Now i am worried I will be under carbed. The 354 is bored to 4.00 with 392 pistons and has an isky cam. Will 3 94s be enough? I really wanted a 4x2 but ended up with the 3x2. I suppose I would run the front and rear as primaries and the middle as the secondary.. anyone have any suggestions.
     
  2. Ghost28
    Joined: Nov 23, 2008
    Posts: 3,200

    Ghost28
    Member

    We ran twin 500 edelbrock 4s on a tunnel ram manifold with about your same configuration. A 354 hemi and it ran good as long as you throttled it up once in awhile. It's now blown with the same carbs and runs real good. You should be fine
     
  3. Don Martin
    Joined: Nov 2, 2006
    Posts: 191

    Don Martin
    Member
    from West Tenn

    I want 3-2s on my 331. Do you want to sell your intake?
     
  4. jobbless
    Joined: Oct 11, 2004
    Posts: 303

    jobbless
    Member

    Not interested in selling. Possible trade for 4x2 though.. i think I would be better off with another carb. At least I would feel better..
     

  5. dutch rudder
    Joined: Jan 15, 2012
    Posts: 146

    dutch rudder
    Member
    from houston

  6. jobbless
    Joined: Oct 11, 2004
    Posts: 303

    jobbless
    Member

  7. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

  8. Andy
    Joined: Nov 17, 2002
    Posts: 5,121

    Andy
    Member

    I think I remember some problem with putting 392 pistons in a 354. The pins were higher and you lost a lot of compression? You might want to check it out.
     
  9. 73RR
    Joined: Jan 29, 2007
    Posts: 7,198

    73RR
    Member

    The difference is that the 392 piston has a smaller dome volume because it has more swept volume (than a 354) so in a 354 the compression naturally is less and, generally, the pistons don't actually make the advertised compression to start with, so..... some day I guess that I'll have to set one up and show the process.

    As to the 3-carb set-up, the old 94 and 97 types don't flow much air, something like 150-175 cfm?
    Mopars from the 60's and 70's used some big Holley 2-bbl on the 400 and they are rated around 300+ cfm IIRC so the 3-97 deal will work on a 354, just not much extra available.

    .
     
  10. George
    Joined: Jan 1, 2005
    Posts: 7,725

    George
    Member

    3 97s is 450 CFM, would need to run nonprogressive or the end 2 as primary & the middle as progressive. 10:1 392 pistons in a 354 give about 9:1.
     
  11. geoking
    Joined: Nov 12, 2008
    Posts: 717

    geoking
    Member


    That's about 150 cfm's short at 6000 rpm. I would use a 670cfm electric choke with vacuum secondary.
     
  12. George
    Joined: Jan 1, 2005
    Posts: 7,725

    George
    Member

    1. that's why people like the 4X2 Cragars & weiands, comes out right! 2. A single 4 bl of apx the same size as the multi-carb setup will always be a more efficient choice, just not look as good.
     
  13. strombergs97
    Joined: May 22, 2006
    Posts: 1,888

    strombergs97
    Member
    from California

    First, what about running 3 Stromberg 48s, that would give you 525 CFMs. and I would run them all at the same time, no progressive..
    Here is a picture of a Aluminum custom built 4x2. OH, it's up for sale..
    Duane.
     

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  14. 73RR
    Joined: Jan 29, 2007
    Posts: 7,198

    73RR
    Member


    Duane, have you ever had an opportunity to run one of these design manifolds on a dyno?

    .
     
  15. Rob Paul
    Joined: Nov 11, 2005
    Posts: 1,272

    Rob Paul
    Member

    Im down with this idea. Save a few bucks running 48's, get some extra cfms, and see what happens. Straight linkage. You might be really happy with it.

    BTW, what intake do you have?

    Rob


     
  16. jobbless
    Joined: Oct 11, 2004
    Posts: 303

    jobbless
    Member

    It's a Weiand WC3D pretty cool intake. Maybe I will try to find adapters and run the 2gc carbs.
     
  17. strombergs97
    Joined: May 22, 2006
    Posts: 1,888

    strombergs97
    Member
    from California

    73RR...Have not dyno it but put one on a 392, mild build. Ran all 4 97s and the engine loved it and ran great..I believe that the Hemis like the long runners..
    Duane.
     
  18. strombergs97
    Joined: May 22, 2006
    Posts: 1,888

    strombergs97
    Member
    from California

    For the price and some work you could make the 48s about 195 to 200 CFMs..But you would need to buy 48 jets, 63 power valve. Now, cut the venturi tubs off, flush with the flange on the bottom of the body, remove the emulsion tubs and carefully with a fine stone enlarge the venturies..Old hot rodders trick..Now remove the throttle plates and file the down and areas of the throttle shaft. You might even get more CFMs...
    Just and idea..
    Duane.
     
  19. strombergs97
    Joined: May 22, 2006
    Posts: 1,888

    strombergs97
    Member
    from California

    Did you know that with oversize throttle shafts you can loose up to 7 CFMs..
    Duane.
     
  20. uncle max
    Joined: Jan 19, 2006
    Posts: 908

    uncle max
    ALLIANCE MEMBER

    Just wait a few weeks, save your money and order three of the new 235 cfm double powervalved Strombergs from England!
     
  21. jobbless
    Joined: Oct 11, 2004
    Posts: 303

    jobbless
    Member

    Tell me more....
     

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