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banger 2x2 help

Discussion in 'The Hokey Ass Message Board' started by kevins29truck, Mar 3, 2009.

  1. kevins29truck
    Joined: Mar 3, 2009
    Posts: 30

    kevins29truck
    Member
    from ohio

    Got a model A flathead i built with a thomas 2x2 intake and a pair of 94's. I made 102 horsepower but my plugs appeared to read way too lean. I am running 55 jets in my primary carb, and 60 in my secondary carb. Need help from guys running dual carb setups, as far as what jets you are running. This hasnt seen road time yet to do any more tuning. Ran out of dyno time so i was unable to jet up more at the time. Just curious to hear some thoughts and get some help. Oh also running 5.5 power valve, and i am going to try going smaller on that too.
     
  2. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    Check the March Banger Meet...
     
  3. I'm not a banger expert but this sounds weird. I have an 8BA that consistently runs rich with dual 94's and stock jets and 3.5 power valves!
     
  4. lonewolf
    Joined: Sep 2, 2006
    Posts: 393

    lonewolf
    Member

    wow 102 hp and running lean..........sounds like it will be nice when you get the bugs out...wish you well
     
  5. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,681

    Bruce Lancaster
    Member Emeritus

    Does the secondary still have its off-idle circuit or is that plugged?? The off idle feed is important up to a fairly high RPM until there is enough flow to energize the venturis fully. Your jets are huge...I think you have been jacking up jet size to compensate for a lack elsewhere.
    I would think about...going to straight linkage, after first temporarily blocking off secondary and getting a single carb dialed in, then dialing in the other carb by itself too.
    You should be needing something close to stock jets, like around .050, when all is hashed out.
    According to Ford, a 221 V8 is running partially on off-idle up to something like 1500...the more carb you have, the later the venturis can energize enough to handle all needed gas.
    Also, what is float level?? Something is wrong and being compensated by big jets.
     
  6. panic
    Joined: Jan 3, 2004
    Posts: 1,450

    panic

    what is float level?? Something is wrong and being compensated by big jets

    I agree - float too low, low fuel pressure, air bleeding into the main well somewhere.
     
  7. kevins29truck
    Joined: Mar 3, 2009
    Posts: 30

    kevins29truck
    Member
    from ohio

    I hope to have it on the road soon to see whats going on when i have more time to play and read things. I have no idle circuits and no power valve in the second carb. there blocked off. the secondary is feeding just through the jets. I started with stock jetting and going up a few sizes netted more power. so i was curious if anyone else had similar setups and was running big jets or if most were jetting down. I have more experimenting to do.
     
  8. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,681

    Bruce Lancaster
    Member Emeritus

    My immediate thought for investigation...when secondary opens, it is perhaps feeding air but very little gas without the transition circuit. Until engine gets to fairly high RPM, very little gas can flow through the main feeds and only the off-idle is producing.
    Flog the carbs one at a time as only carbs. What float height are you using?
     
  9. kevins29truck
    Joined: Mar 3, 2009
    Posts: 30

    kevins29truck
    Member
    from ohio

    i will have to double check my float levels. What would be suggested. I shouldn't have any air leaks. I redid both of these carbs and spent the money on them. I have an aftermarket baseplate in my secondary carb which is air tight, and i put an oversize throttle shaft in my primary carb to tighten it up, as well as everything else. My bodies were good shape and checked for warpage, and all was good. So if i am moving air with little fuel in the secondaries, is there a way to sort it out, or do you live with that?
     
  10. BCCHOPIT
    Joined: Aug 10, 2008
    Posts: 2,601

    BCCHOPIT
    Member

    I 3rd the check the float. Is your intake getting real cold? IF your intake is running cold you have to make up for it with more gas. I am only running one 94 on mine the intake has ice on it in the summer. It would run fine in the drive way but run down the street it would spit and sputer went up the the jets till it ran good. put over 1000 miles on the little banger last year.
    good luck
    Bill
     
  11. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,681

    Bruce Lancaster
    Member Emeritus

    If your secondary is right on float, dirt, airbleeds and is not passing any gas it is because of the IDLE and OFF IDLE circuit and because when it opens there is not enough airflow to activate main circuit at venturis. Get the blocked circuits ope, go to straight linkage AFTER flogging the carbs separately as above. Your little engine is not going to pull anything through main circuit til it is spinning pretty fast. You have turned off the faucets in your secondary. And post actual float level. Most 94 uses like LOW float level. Just for informations sake, it would be interesting to try your with float at high limit...that might speed main circuit tip-in. Still, you need gas at low RPM, and yours is plugged there.
     

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