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Holley #1920
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Author:  Dan [ Mon Sep 24, 2001 5:27 am ]
Post subject:  Holley #1920

Can anyone tell me the cfm of the Holley # 1920 carb?

reptylkrib@aol.com

Author:  Craig [ Mon Sep 24, 2001 6:50 am ]
Post subject:  Re: Holley Carburetor flow ratings CFM

According to information in a book, Holley Carburetors & Manifolds, that I have. . .

The 1920 carb came in flow capacities of 160 and 235 CFM (flow at 3.0 inches Hg). Throttle bores are 1-9/16 and 1-11/16 inch.

The 1945 carb came in one size wilth a 1-11/16-inch throttle bore and flows 203 CFM at 3.0-inch Hg pressure drop.

(Hg is the chemical symbol for mercury. Most vacuum gauges we use here are calibrated to read in "Inches of Hg" meaning "inches of mercury".)

NOTE - You can NOT directly compare CFM rating of 1- and 2-bbl carbs to ratings of 4-bbl carbs. 4-bbl carbs are usually rated at 1.5 inches Hg pressure drop whereas 1- and 2-bbl carbs are rated at 3 in. Hg pressure drop.

To relate the two measurements, use the formula

CFM flow at 3 in. Hg / 1.414 = Equivalent flow at 1.5 in. Hg

Example: for a 235 CFM 1-bbl carb

235 / 1.414 = 166 CFM four-barrel equivalent

Hope this helps.
CF



cfield@ll.net

Author:  Dan [ Tue Sep 25, 2001 5:05 am ]
Post subject:  Re: Holley Carburetor flow ratings CFM

Thanks, this is just what I needed to know!
God bless America!
Dan
Quote:
:
: According to information in a book, Holley
: Carburetors & Manifolds, that I have. .
: .
:
: The 1920 carb came in flow capacities of 160
: and 235 CFM (flow at 3.0 inches Hg).
: Throttle bores are 1-9/16 and 1-11/16 inch.
:
: The 1945 carb came in one size wilth a
: 1-11/16-inch throttle bore and flows 203 CFM
: at 3.0-inch Hg pressure drop.
:
: (Hg is the chemical symbol for mercury. Most
: vacuum gauges we use here are calibrated to
: read in "Inches of Hg" meaning
: "inches of mercury".)
:
: NOTE - You can NOT directly compare CFM rating
: of 1- and 2-bbl carbs to ratings of 4-bbl
: carbs. 4-bbl carbs are usually rated at 1.5
: inches Hg pressure drop whereas 1- and 2-bbl
: carbs are rated at 3 in. Hg pressure drop.
:
: To relate the two measurements, use the formula
:
: CFM flow at 3 in. Hg / 1.414 = Equivalent flow
: at 1.5 in. Hg
:
: Example: for a 235 CFM 1-bbl carb
:
: 235 / 1.414 = 166 CFM four-barrel equivalent
:
: Hope this helps.
: CF



reptylkrib@aol.com

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