Here are some of the latest 3D's showing how the float
  bowl moves up and down a half inch to lean the mixture.

  The scale on this DWG is more accurate as I found
  my Holley 4 barrel to measure.

  BTW if you apply dynamic pressure to the float bowl
  the delivered mixture will be a function of both vacuum
  in the venturi throat plus the square law dynamic pressure
  In other words the dynamic pressure in the
  intake runners will be the square of the air velocity.
  At full chat that can be as high as 300 MPH.
  Sort of a mini pito tube in the intake runner.

  I am not sure this is what you want but it can always
  be leaned and the bottom line is: the fuel will squirt
  out into the intake runner better.

  I learned this trick from Ellison.

  The more I work on this the better it looks.

  You will be up and running in 5 minutes not
  one year tuning an EFI in the air.

  There are only four cheap parts to make.
  The rest of the needed parts are stock Holley.
  One can buy a brand new 4 barrel Holley for $250 to scavenge
  the parts from. Perhaps someone can find some on ebay.

  Paul Lamar

  You can run the bowl vent through a fish tank brass valve. (used to
  control airflow into bubbling devices in fish tanks) Run a remote
  cable
  through the thumb screw on the valve to be able to change it from the
  dash.
  Jet the carb over-rich and lean it by limiting local air pressure
  in the
  bowl. Done on dyno engines to avoid changing jets looking for best
  mixture.
  Lynn E. Hanover

  Would that trick work on a Weber DCOE?

  Everett Rankin

  Probably. Assuming the Weber float bowl is now vented to the
  atmosphere.


  Paul Lamar



  What ever happened to the Ellison knock-off project we were discussing a
  year or two ago?

  Mark

  Too expensive. There is a reason Ellison charges $1000.
  All those tiny laser holes are a pain in the wallet :)

  Paul Lamar


  Oh, that figures. Seems like a great design. Why don't we build our
  own laser? (Just kidding.)

  Mark


  Here is another chart from that great book I mentioned above.

  One might also say why don't we just buy an aircraft carb? That can be
  made to work of course but when is the last time you saw a side draft
  aircraft carb? :)

  Paul Lamar


 The side draft carb is a Marvel-Schebler HA-6, used on 180-260
 horsepower lycomings. Grumman Tiger, some Beech Musketeers, et al.

 Victor Roberts

 I stand corrected. I should have said; "side draft slide throttle" :)

 At $1600 to $1800 each we would need two.

 Paul Lamar

  Hi  Paul,
                  Why reinvent the wheel, or am I missing something
here? Below is a link to adjustable Holley 2 barrel carbys.

http://www.circletrack.com/techarticles/ctrp_0303_holley_carburetor_tunable_metering_block/viewall.html
           I would have thought that would be easy rather than reinvent
a carburettor.
         John Burey