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Jan 7, 2017 | 10:00 AM

#16

FuzzFace2

FTE Legend

Joined: Nov 2015

Posts: 30,935

Likes: 4,124

From: Angier, NC

One of the things I have not see brought up in this air flow thing is the gap between top of carb and the air filter assy. lid.

A lid too close to the top of the carb on an open element filer assy. can hurt more then using the stock filter assy.

I wonder if that is why the need of different springs on the Holley carb?

I don't think I seen it but any one do flow test and have numbers on a stock filter assy. to say they choke off incoming air?
Dave ----

Jan 7, 2017 | 05:06 PM

#17

Franklin2

Moderator

Joined: Jan 2001

Posts: 56,992

Likes: 2,741

From: Virginia

Quote:

Originally Posted by FuzzFace2

No, the reason for different springs with a open filter aircleaner vs factory is the difference in vacuum developed in the venturi area. The open aircleaner flows so much better than the factory one, the vacuum in the venturi area is dramatically different, and this affects the vacuum available to the secondary diaphragm in the rear barrel holley setup.

We are not talking about engine vacuum, but vacuum developed by the venturi. Of course this is what makes the fuel flow up from the bowel through the jets and into the venturi, and holley also used this to monitor and time when the secondary barrels came in. The carter/edelbrock and the quadrajets use a air door much like a choke door with a spring behind it to bring their secondaries in.