can an edel 500 become a 600??

[marco_1978_spyder]

Reading the specs of both a 500 and 600 series edelbrock carbs I notice that the only difference between a 500 and 600 cfm carb is the calibrations... the throttle bores are the same size as are all other critical dimensions.

Is there something else about the castings that vary the CFMs? Isnt that all about throttle bore size?

[92turbogtz]

Just guessing but I would think there are a number of differences in jetting, idle circuit sizes, power valves among other things.

[cjbiagi]

It's been a looonnngggg time since I put my 500cfm AFB on but I thought the 500 and 600 had the same size primary's but the secondaries were slightly bigger on the 600? I believe the primary venturi's are 1 3/16" on both but the 500 has 1 1/4" secondaries and the 600 has 1 9/16' secondaries.

[marco_1978_spyder]

All those dimensions are identical, according to the owners manual...


That's what has me wondering if it's just the jets and rods..

Then I could set mine up to a model I think might be even better for my engine.

Carb CFM Main Main Metering Step-Up Needle Float Float Pump Accelerator Venturi Venturi Throttle Throttle
Part Jet Jet Rod Spring & Seat Height Drop Drive Pump Diameter Diameter Bore Bore
No. Primary Secondary (Primary (±1/4") Link Nozzle Primaries Secondaries Diameter Diameter
only) Location Diameter Primaries Secondary
1403 500 .086" .095" .065" x .052" orange (5") .0935" 7/16" 1-1/4" middle hole .028" 1-3/16" 1-9/16" 1-7/16" 1-11/16"
1404 500 .086" .095" .065" x .052" orange (5") .0935" 7/16" 1-1/4" middle hole .028" 1-3/16" 1-9/16" 1-7/16" 1-11/16"
1405 600 .100" .095" .070" x .047" orange (5") .0935" 7/16" 1-1/4" middle hole .028" 1-3/16" 1-9/16" 1-7/16" 1-11/16"
1406 600 .098" .095" .075" x .047" yellow (4") .0935" 7/16" 1-1/4" middle hole .031" 1-3/16" 1-9/16" 1-7/16" 1-11/16"

[cosvega76]

I bought a 500 Edelbrock for my wife's 289 Mustang, and I was surprised by how small the primary venturis were. The throttle bores may be the same, but with smaller venturis, the calibration will certainly be different. I would stick with the recommendations found the the Tuning Manual.

Chuck

[starfire383]

CFM is a measure of airflow thru the throttle bores. Cubic Feet Per Minute. Jetting and rods have zero to do with the CFM rating, if you want to change CFM then the bores must get bigger or smaller. Jetting and rods only change how much gas is contained in the air. Not the volume of air.

Even if the carbs look the same, they're different bores. Guaranteed.

Sometimes they'll do a trick like using the same baseplate or top plate on a 500 and 600. But the main body bores will be different.

Sometimes you can also cheat a few CFMs with a fancy booster, since the boosters hang out into the airstream. But we're talking minor differences like 20 cfm, and the boosters are pricey.

good luck

[marco_1978_spyder]

Ok, thanks! Thats pretty much what I thought.

With that, I can think about trading for the carb I'd like, rather than thinking about trying to turn what I have into something else, it can't be.