A couple more holley 1920 questions

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Slowswinger

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There is a angled hole in the base of my 1920 and a hole in the throttle plate. Did they come from Holly this way? The hole in the base would let in unfiltered air.
 

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i think so. the hole in the casting is a vapor vent. so vapor doesnt build up at the plate then get dumped into the carb the next time the throttle is opened. the hole in the plate is part of the idle speed control system. when you put the plate back on be VERY careful that the diameter of the plate is sealed good, before you tighten the screws.
 
That hole in the carb base looks totally bogus. There should be no place for unfiltered air to come in like that for an auto application. It does not look a normal location for a port, and that is evidenced by no support casting around that area. I will venture to guess that somene added that to try to tune the carb, or it is a manufacturing item that gets plugged and the plug fell out.

The hole in the plate looks legit.
 
I was kind of wondering about that do to the unfiltered air being sucked in. Although the angle that it is drilled/?? at and how clean the hole is does not make me think shade tree carb modification, it's a very clean hole.
 
It just doesn't make sense for it to be there, unless it is an auxiliary ported vaccum port. But that is the port right below it.

Check this Mike's Carbs video on their remanufactured 1920; it shows this exact area soon after the video starts around 12 seconds....no hole!
http://www.carburetor-parts.com/Holley-1920-Remanufactured-Carburetor_p_2934.html

IMO.....someone has been dorking with this....plug it with a soft metal material and/or JB. I can make very clean holes with a drill...!!
 
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