Register now to get rid of these ads!

How realistic is it to run 4X2's on "street" flathead?

Discussion in 'The Hokey Ass Message Board' started by banjorear, Feb 21, 2007.

  1. fullhouse296
    Joined: Jan 30, 2009
    Posts: 354

    fullhouse296
    Member
    from Australia

    Hey ." HOT ROD FREAK " . Where did you get those groovy finned head covers ?
     
  2. 31ACoupe
    Joined: Nov 14, 2005
    Posts: 1,416

    31ACoupe
    Member

    Very clearly said, I agree with this, and maybe the approach would be to run the 4x2 and block the fuel supply to the second or third carb or even both and run on 2 or 3 carbs. You get a great looking motor and maybe more even performance.
     
  3. dirty old man
    Joined: Feb 2, 2008
    Posts: 7,931

    dirty old man
    ALLIANCE MEMBER

    Call me a grouchy old fart. or whatever, but I'll be damned if I can understand how the last post on this thread can come from anybody with any reading comprehension at all.
    Not after Bruce has done an excellent job of explaining that 4-2s on a flat motor uses a manifold that basically creates 8 IR throats with only small equalizer passages between the throats and Flat Ernie has related hands on experience with these 4-2 setups and that they require straight linkage and an operating carb throat at each hole or they won't work and I myself have related that all of these 4-2s I've ever seen were on straight linkage!
    Sometimes I wonder why we bother!
    Dave
     
    falcongeorge likes this.
  4. Pete1
    Joined: Aug 23, 2004
    Posts: 1,585

    Pete1
    Member
    from Wa.

    I think there has been several threads on this before.
    4 97's or 48's work fine on the street.
    I have set up about 40 of them over the years.
    Straight linkage.
    In the 50's I drove mine to work 5 days a week, raced on weekends
    and in August of 1953 drove it to Bonneville, ran all week and drove it home...Best time was 130.03.
    Go for it.
     
    Last edited: Feb 10, 2009
    volvobrynk likes this.
  5. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,604

    Bruce Lancaster
    ALLIANCE MEMBER

    Hey, Pete, can you talk about tuning issues on these things? My thought is that 1 barrel/1 cylinder can lead to some fierce pulsing at some speeds without a plenum or other cylinders to control things. Air that goes in-out-in can obviously pick up more gas than it should. What did you go through taming the metering needs?? I haven't gotten hold of a 4 yet (anyone need a triple and want to trade?) but the idea is interesting, especially after reading some IR stuff by Vizard.
     
  6. fullhouse296
    Joined: Jan 30, 2009
    Posts: 354

    fullhouse296
    Member
    from Australia

    You can run four 2s easy ,on the street in a heavy vehicle .this is how its done .Make a 4x2 box section plenham to bolt to the 4 carb manifold using extended studs right the way through .Dont forget to get it milled flat.Check that all the holes match up.Paint it silver and with a progressive linkage ,this has no flat spots.Check jetting .
     
  7. big duece
    Joined: Jul 28, 2008
    Posts: 5,403

    big duece
    Member
    from kansas

    Bringing this thread back from the dead. Let' say the 4 barrel manifold for the flathead uses the 390 cfm holley, wcfb, or up to 500cfm with a common plenum. The true IR runner systems start basing the choke size on the intake valve diameter. On a scale of 1 to 10, where would the Edelbrock 4x2 be gauged as being close to a IR intake? By looking at my 4x2 intake MOST of the path is a straight shot from the carb base to the valve. There is a plenum balance area between all carb pads, but they are very small; like ring finger size. My point it is, if it breathes almost like a IR, one could use 4 carbs with their total cfm being higher that a single 1x4 carb. Bruce, Pete1 any feedback??
     
  8. volvobrynk
    Joined: Jan 30, 2011
    Posts: 3,588

    volvobrynk
    Member
    from Denmark

    Pics?

    It's possible, but the mixing and matching of carbs make a very important factor in the build, because the right size for your engine might be a little hard on the wallet.

    Or do you have the carbs?
    How hot is the flathead? Manual or auto? Roadster or truck?
    Do you drive it like you are sixteen all over again?
     
  9. big duece
    Joined: Jul 28, 2008
    Posts: 5,403

    big duece
    Member
    from kansas

    This is a hole different animal I am working on. Mild flathead, manual trans, light car(eventually). Not going to be a hard driver with this one. These carbs have the adjustable choke feature, but the smallest choke is still a bit too large. I can have custom chokes made to 28mm, which is close to the cfm of what a wcfb would flow. But since my 4x2 intake is more like a IR rather than a 1x4 plenum, the chokes could be opened up a bit, to maybe 32-33mm. Other jetting in come in after choke size is established. 001.JPG DSC09508.JPG DSC09507.JPG
     
    volvobrynk likes this.
  10. FlatJan
    Joined: Dec 13, 2013
    Posts: 211

    FlatJan
    Member
    from TX

    what day month year has your flatty been casted and rebuilt?
     
    Last edited: Oct 16, 2016
  11. ghornbostel
    Joined: Jan 3, 2012
    Posts: 131

    ghornbostel
    Member

    Why not put 4 dcnf webers on this manifold and tune it as a true ir induction.


    Sent from my iPhone using The H.A.M.B. mobile app
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.