What are these holes for?

[Cadman-iac]

  While looking at my carburetor I noticed that these holes are not always the same size.
 On a Chevrolet, they seem to be  .029" in diameter, but on a Cadillac or Oldsmobile they are as big as  .055".

 What does this do, and how does it effect the AFR ?
  Are these an air bleed for the main wells, and why would there be different sizes?
 How do they affect the AFR?

 

[Cadman-iac]

  Cliff,

  How much does the size of this hole affect your AFR? I don't know what the range is for these, I've seen them from  .029" to .055". The  .029 being on a Chevrolet carb, the  .055 on a Cadillac and an Oldsmobile, I don't have any Pontiac carbs to look at.

 I ask because I'm running a Cadillac carb from a 425, #17057230, on a 350 Chevrolet, and I set it up with the recommendations you gave me for a 350 using this carb.
 However I keep having a lean condition at certain RPM's and engine loads, and I'm wondering if this hole is a factor.
 How do you compensate for the larger hole? This is the main well air bleed, correct?

 Rick

[novadude]

Bumping this to the top, as I am also curious about how these bleeds affect fuel curve.

[Cadman-iac]

Nothing?

[Cadman-iac]

Still nothing?

[77cruiser]

Where's Tuner?

[Cadman-iac]

  Still curious about how the size of the main nozzle air bleeds affect the AFR, and the relationship between these and the main jet size.
 Cliff?