Dual 4 setup??

[Truckedup]

I'm no expert but I think a pair of 4 bbl's would be best if the carbs were not progressive and both carb primaries open at the same time for better part throttle fuel distribution..I do know the AFB's had a lot of subtle differences on the various models....

[Tuner]

I race nostalgia super stock, and we have to run a dual four manifold that fits under the correct OEM hood scoop. I have run the 64 cross ram and a homemade dual four manifold, and have set up several others for different people. I have been running the federal mogul AFB's They are cheap on Ebay, last pair I bought were $75.00 each On the calibration what I do is I set up the carb on my flow bench, and I have an adapter made to hook the velocity probe to the carb jet. I drilled out a jet and soldered a small brass tube. Then I check the flow through the jet. I mix and match clusters from different carbs until I get pairs of primary and secondary venturi's that flow the same amount. Usually I polish the venture, and sharpen the edges as well during this process. My methods are just something I came up with, and it seems to work. I can then build and sell the ones I don't want as singles for street engines. I have been running the 750's but I would think any CFM would work as long as the list numbers are the same.

You might like to study this 100 year old tidbit. https://ntrs.nasa.gov/search.jsp?R=19930091078

[quickd100]

I've got a 440 on the Dyno right now but am waiting for warmer weather before I fire it up. I will be testing an old 383 8bbl setup,(using manifold spacers) and a Chrysler short ram setup. I m using a set of matching carbs for a '59 383. The old 383 inline 8bbl setup isn't a barn burner but it looks neat under the hood. I tried one years ago, my M-1 single plain and a 850 Holley made more power.
The original Carter's we're 500 cfm.

[PackardV8]

I've got a 440 on the Dyno right now but am waiting for warmer weather before I fire it up. I will be testing an old 383 8bbl setup,(using manifold spacers) and a Chrysler short ram setup. I m using a set of matching carbs for a '59 383. The old 383 inline 8bbl setup isn't a barn burner but it looks neat under the hood. I tried one years ago, my M-1 single plain and a 850 Holley made more power.
The original Carter's we're 500 cfm.

BTDT - I'm using a Packard Caribbean 2 x 4-bbl setup in my Studebaker truck. It looks just too cool to pass up, but as you found, your M1 1 x 4-bbl intake I converted to fit the Packard did make more power and got better mileage. We're all just stupid hot rodders sometimes.




jack vines

[cjperformance]

Look for matching bore and base plate sizes, cfm ratings are not the end of all. My front carb is 35years older than the back one.
Even with a numbers matching set, there will be so much difference between what each spark plugs wants after the baseline pass, that a "slight" variation between carbs make no difference.

With dual 4's on an old intake particularly a dual plane two slightly different carbs could potentially help.
If you're not out to set records then dont sweat it. Use what you have and then read plugs and et and experiment, switch carbs front to rear, the engine wouldn't actually care if the 2 carbs were a different brand so long as each cylinder were getting what it needs!

[quickd100]

I've got a 440 on the Dyno right now but am waiting for warmer weather before I fire it up. I will be testing an old 383 8bbl setup,(using manifold spacers) and a Chrysler short ram setup. I m using a set of matching carbs for a '59 383. The old 383 inline 8bbl setup isn't a barn burner but it looks neat under the hood. I tried one years ago, my M-1 single plain and a 850 Holley made more power.
The original Carter's we're 500 cfm.

BTDT - I'm using a Packard Caribbean 2 x 4-bbl setup in my Studebaker truck. It looks just too cool to pass up, but as you found, your M1 1 x 4-bbl intake I converted to fit the Packard did make more power and got better mileage. We're all just stupid hot rodders sometimes.




jack vines

I can't disagree, I ve pounded my head against the wall to many times just because of the "Cool factor" some part held over me. Sometimes though it's been because someone told me that I couldn't make it work.

[F-BIRD'88]

This old 50's era low rise dual quad stuff was not designed nor intended for high horsepower.
Internally too small. Too low height.

[Tuner]

I've got a 440 on the Dyno right now but am waiting for warmer weather before I fire it up. I will be testing an old 383 8bbl setup,(using manifold spacers) and a Chrysler short ram setup. I m using a set of matching carbs for a '59 383. The old 383 inline 8bbl setup isn't a barn burner but it looks neat under the hood. I tried one years ago, my M-1 single plain and a 850 Holley made more power.
The original Carter's we're 500 cfm.

BTDT - I'm using a Packard Caribbean 2 x 4-bbl setup in my Studebaker truck. It looks just too cool to pass up, but as you found, your M1 1 x 4-bbl intake I converted to fit the Packard did make more power and got better mileage. We're all just stupid hot rodders sometimes.




jack vines

I can't disagree, I ve pounded my head against the wall to many times just because of the "Cool factor" some part held over me. Sometimes though it's been because someone told me that I couldn't make it work.

Was it you that had a pair of TQuads on a T-ram a while back?

[quickd100]

Yep that's me. The Thermoquads work fantastic on my 605!

[Geoff2]

Good to see TQs being used. A most underrated carb.