What CFM am I looking for

[Scruffy]

I am now planning to buy a 4 barrel carb to go with my 4 barrel Edelbrock intake manifold. The one I have my eye on is a 600 CFM unit,it 600 CFM what I need for my AMC 360? These things still confuse me. Also,I think I may purchase an aluminum 1" carb/intake spacer for added performance. Has anyone had any luck with these,or are they simply not worth the money? Thanks in advance.

[bignblue]

I think the max cfm is 650 for a 360, but that's with a hotter-than-stock cam. Why not look into the complete Performer package? It comes with carb, cam, lifters and intake (which you already have...I know).

[joe]

600 CFM is fine for your 360. I'm running a 600 cfm Edelbrock 1405 on a stock 73 AMC 4v manifold and it works good. BUT...if you're planning on serious offroad/off-camber work keep you're 2v.
Just my opinon but for offroad work any 2v carb is better than any 4v carb
-joe

[SpruceMoose]

another 2 cents worth: 2bbl holley fuel injection. cured all my stumbling, hesitation problems, should work at any angle, huge power increase off idle (like when leaving a stop light). and this was with a used, old analog unit.

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88 Grand Wagoneer
"Spruce Moose"
AMC 360
DANA 44 F/R 2.72
TF 727
NP 229
Jacobs Pro-Street Ign.
Edelbrock Intake
Holley 2bbl Pro-Jection
Flowmaster 2.5" 50 Series Delta muffler and tubing
Amzoil foam air filter
Amzoil fluids all around
30x9.5 BFG AT

Mileage? We don't need no stinkin' mileage!

[SpruceMoose]

oops, forgot: no more pinging - at all! also you can adjust fuel mixture fron inside the car while driving. unit is 670 cfm. there are others in the product line with higher cfms, but you dont need it with these low-flow / high torque 360s.

[78Chief]

How bout on a 401?

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78 Chief
401 (The Beast)
33" BFG a/t
Hey It's Big and Green!

Screw Al Gore!

[RudyC]

600cfm is fine for the 360 or 401.
Both holleys and edelbrocks are sensitive off road but Efi can pretty much run upsidedown. I think the motorcraft 4bbls are the same design as the 2bbls so they should work off road as well as the 2bbl.
The only carb that i had that was excellent off road was the Q jet and they are about 795 cfm at full HONK mode.

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1979 WAGONEER, 360, TH400, Q- TRAC. 3" ADD A LEAFS, 31" MUD T/A'S (PEP BOYS CLONES).
" Go farther, it only breaks on the street"

[Ralph]

The basic mathematical formula for relating engine size and maximum RPM to carburetor airflow capacity is:

Carb CFM = (engine CID x maximum RPM)/3456

The number 3456 is simply number of cubic inches in a cubic foot (1728), times 2 because a 4-cycle engine takes in its full capacity of air during the intake stroke every other revolution.

What this translates to is that a 360 cid engine operating within Edelbrock's claimed effective range of 0-5500 RPM (for the Performer series cams & carbs) would require a carb with no greater capacity than 573 CFM.

That figure assumes 100% volumetric efficiency (V.E.), although engines such as the V-8's in FSJ's usually run around 75% V.E. So a carb with capacity of just 430 CFM should satisfy the needs of an AMC V-8, particularly if the engine is not regularly run at high RPM's. For further reference, check out the following link:
http://www.ponycarburetors.com/calculating_cfm.htm


[This message has been edited by Ralph (edited November 20, 2000).]

[Veepster]

Thanks Ralph! I was dreading researching all those formulas and such.....do you know what is the CFM rating of the 2150?

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Peace.............BartG

the Green Flash!
78 Cherokee
360 2v, TH400 QT with low
4" skyjacker Rancho 9000's
33x12.50 BFG KO's 8" American Racing Baja Rims
Thorley headers, 3" exhaust, Dyno Max
Infiniti power leather seats
50%Luxury Car, 50%Tractor
http://www.teamgodspeed.com

[lanierboy]

I understand the benefits of the Edelbrock manifold and performance Cam but, are there any negative side effects like poor idling or anything else?

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1987 GW "Christine"
AMC360 / NP229 / TF727
Holley Projection 2bbl
TFI Ignition upgrade

[angry joe]

I have a 360mtr with an edlebrock performer intake non egr and 600 cfm carb. In my opioin this set up works prefectly fine for me. Except for the fact that I'm at the gas station more than I imagined. However, It runs and idle's fine. I'm still in the process of putting in a cam to complete the package.The pamphlet that came with the carb suggested not to put the 1" spacer for my paticular application. good luck!
http://www.ifsja.org/ubb/mad.gif angry joe

[Ralph]

I think, but am not sure, that the 2150 is rated at around 400 CFM. I'm sure somebody has the correct answer.