Airflow requirement

Discussion in 'High Performance Modifications' started by biker, Sep 16, 2017.

  1. biker

    biker Veteran Member

    So, I thought I was running out of fuel around 4000ish rpm. I replaced fuel pump and a section of squishy rubber hosefeeding the pump and I also replaced hard line to carb with a nifty 3/8 hydraulic hose and fittings that may not appeal to purists, but has a cool industrial look to it and is very hearty (heat, vibration etc).
    Vastly improved, pulls harder with no stumble at 4-5000, but gets soft above that.
    Valve springs are plenty good, so not a float issue.
    What I do have is stock air cleaner with a 2" element, 11 inches across. Roller cam is 540 lift and 240ish@ .050, peak power @ 6000 rpm, 110 lobe sep. RPM intake, 195 heads, Quadrajet. Am I running out of air?
    I still havent found a drop base air cleaner that will let me use a 3" x 14" filter element, and my hood barely closes now.
    If I stay out of the secondaries, response and rpm are awesome. Secondaries feel like rocket power until 5000ish.

    Brent.
     
  2. Skip Fix

    Skip Fix Veteran Member

    1,991
    4
    Mar 21, 2007
    Katy,Texas
    Sounds typical of a fuel delivery problem. Pump , line size.
     
  3. biker

    biker Veteran Member

    10-4. Rest of the rubber lines are good, pickup is new, pump is new Delco with return, I may try upping the float level, I would think that will declare if it is a fuel problem, while not being a fix, but an indicator that I need more fuel.
    Still suspicious of airflow too. If anyone knows of a magical base that will allow a 3" filter with a small block and RPM intake, let me know.
     
  4. muscl car

    muscl car Veteran Member Lifetime Gold Member

    Make sure you've got 3/4" - 1" clearance between your float bowl vent and air cleaner lid
     
  5. biker

    biker Veteran Member

    Yes. Good advice. If i had to get closer, I'll find a way to vent the bowl to atmosphrere outside the filtered area.
     
  6. muscl car

    muscl car Veteran Member Lifetime Gold Member

  7. biker

    biker Veteran Member

  8. mrdragster1970

    mrdragster1970 Veteran Member Lifetime Gold Member

    .


    Take the cleaner off and test.
    A tiny bit of unfiltered air won't kill you.
    Look at how much un-filtered air I use every pass.


    .
     
  9. biker

    biker Veteran Member

    Very true. Sometimes the easiest thing is too obvious to see.
     
  10. mrdragster1970

    mrdragster1970 Veteran Member Lifetime Gold Member

    .


    I might be a big mouth jerk, but I've done this awhile.
    I've had the fiberglass hood flex and cover the vents, I've had the scoop force in too much air and lean out,
    so we put duct tape over the opening, I've had the needle stick, air bleeds get dirt etc etc.
    All stuff I tore my hair out over because I didn't think of the simple fix.



    .
     
    Goodwrench1965 and 1972_Z-28 like this.

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