Packard Forum Index » V-8 (1955-56)

Anyone know the CFM rating for this carb?

From Hemmings:

"Earlier 4GC models were only available in 486, 553, or 692 CFM."

I believe only the first two sizes were used by Packard.

From a hemmings article (FWIW):
"Earlier 4GC models were only available in 486, 553, or 692 CFM"

From a random internet forum post:

"Used on a variety of GM automobiles from 1952 to 1967, including the 1961 to 1963 Buick/Oldsmobile/Pontiac aluminum 215 V8's, the 4G was Rochester's first four barrel. Produced in 486, 553, and 692 CFM ratings, the 4G uses a squarebore layout with a conventional fixed jet, power valve and accelerator pump metering scheme."

And a size chart:

Model /CFM Venturi Diameter/ Bore Diameter

primary secondary / primary secondary


4 Jet/ 486 1 1/8 1 1/4 / 1 7/16 1 7/16

4 Jet/ 553 1 1/8 1 15/32 / 1 7/16 1 11/16

4 Jet/ 692 1 1/8 1 15/32 / 1 9/16 1 11/16


Hope that helps!

you think there would be a way to know based on the tag number, which mine is missing. ;0(

i am rebuilding mine right now and will have lots of pictures of it soon.

Hank

edit: if anyone has a tag that is appropriate for a 55 352 4gc i'll gladly welcome it with open arms. ;0)

Quote:

To further muddy the water, the Packard Service Manual in the "Specifications - Fuel System" for 5560 & 5580 lists:

4GC/CFM?,1-1/16,1/1-5/16,1-5/16

In a document I have from "Texas Region, Packards Intl" for the the 5588 2x4:

4GC/CFM?/1-1/64,57/64/1-5/16,1-5/16

I have in my notes (but no source ref) that the 5680 is:

4GC/CFM?/1-1/4,1-1/4,/?,?


Craig