4053 DZ SPECS

[McKenzieDave]

I need to verify that a 4053 DZ carb is unmolested.  Does any body out there have the specs on idle feed restrictor and air bleed sizes?

[jdv69z]

From what I have read about Holleys carbs, modifying the air bleeds and idle restrictions is something only an expert should attempt. Otherwise the carb could be become unable to be tuned correctly. Why do you think it has been modified?

Jimmy V.

[McKenzieDave]

Came from a guy who ran it on an old 396 part time drag car.  From other examples of his handy work, I want to be sure.  Biggest concern is I want it for a 302 that is quite close to stock Z/28 specs, I know they worked very well, and I have it laying there just begging to be used.  Dave

[Vintage Musclecar]

Dave;

The primary idle air restrictors on the 4053 DZ carbs are actually left open from the factory. There are two small adjustable air bleed screws located in front of the choke tower which intersect the idle air bleed bosses that you use to adjust the idle air supply. They are normally hidden under a blob of white epoxy on either side of the choke tower, but often the epoxy has deteriorated and the slotted heads of the screws may be visible.

The idle fuel restrictors on the primary side 5583 metering block should be .036"

Hope that helps.
Eric

[jdv69z]

Dave, could you try installing it on the car and see if it will adjust and idle correctly? That would easier for me versus trying to figure out all specs, etc? Hoe do you even measure all those bleed holes etc. without some sophisticated equipment or gages?

Jimmy V.

[McKenzieDave]

Didn't want to waste the time and money on a junk carb.  I measure with a precision hand drill bit set that never gets chucked.  Very accurate through .039 then it it goes fractional, so really close is what you get.  Thanks Vintage.  Dave