440 Dual Quad Carb. Setup/Adjustment

[7Dcuda]

Can someone with experience setting up and adjusting a dual quad setup please tell me the basics?  I have the Edelbrock Dual Quad Intake with two 600 cfm Edelbrock Carbs.   Also have a mild, MOPAR Purple Cam and a set of headers.

At what throttle point should the main carb. be when the linkage begins to activate the second carb?  Also, how do you setup the carb/throttle position and the kickdown linkage?  Any info. on the dual quad setup and adjustment would be appreciated.   

[Cooter]

Well, All I can tell you is how I have My own 440 twin four set up, and how the factory did it..

First, the factory set up the twin fours with "Porgressive" linkage meaning, the linkage ran off the Primaries on the rear carb, then as you tipped in the Rear secondaries, it began to pull in the front primaries and at WOT, all 8 BBLs in....


Now, With my own, I set it up to run on BOTH primaries by linking both carb's to each other...The harder you step on it, the more both carb's come in...

[72hemi]

Do you have the Edelbrock dual quad linkage? If not get it to start.

[nqkjw]

You set up dual quads to work together,not staged.Fuel distribution and dropout would be terrible otherwise.
You need to get an adjustable linkage to tie the two carbs together.
Then you need to synchronise the two carbs.
You only need to do this at idle.The theory being that with both carbs drawing the same at idle the rate of increased draw is the same as engine speed increases.
I use a tool referred to over here as a carby balancer.I'm sure there's something similar you can get over there.
Below is a pic of the dual quads I used to runon my 440(now a mechanical tunnelram sixpack setup)showing what the balance looks like.




You'll probably have to increase the jet size as the available vacuum is now split between 2 carbs and so will be a lot less per carb and you need to overjet to compensate.

Easiest way around kickdown is a Lokar cable kickdown or just go manual valve body.

[dodge freak 2]

I had to lean out my dual Carters on my 318. The primaries were pretty close but the secondaries needed to go down alot for best power.

I run a manual valve body trans and have no pain in the rear kickdown linkage.

Found the trans shifts a bit softer running the carbs  progressive.

[7Dcuda]

Thanks guys....but I was actually looking for info. on how to do the setup.....and BTW I do have the Edelbrock Dual Quad Linkage tieing the 2 carbs together.  Mainly looking for info. on how to properly "synchronize" the 2 carbs. via the linkage.  i.e. at what throttle point on the #1 carb. should the #2 carb. be activated and the proper process for adj. idle and air adj. screw on both.  I've never ran a dual quad set up before so I'm not familiar with how to properly set it up/tune it.  Right now at low to medium throttle things are fine....but at hard acceleration to WOT it starts missing/sputtering so I was wondering if I was either not getting enuf or getting too much gas due to incorrect dual carb setup and or adjustment.       

[dodge freak 2]

I went and Google 440 dual quad edelbrock. Found Edelbrock installation instructions for the CH-28 intake. They like the 1405 carbs with metering rods .070 X .047 with .098 primary jets. Secondary jets are .086 (comes free when you buy a new intake).

36 degrees advance

Says it might be too lean with headers


The CH-28 Dual Quad intake manifold is designed for 413, 426 (wedge), and 440 c.i.d. Chrysler V8 engines

[dodge freak 2]

As for idle settings, I went with setting both carbs up close to each other. I kept the rods and jets the same between both carbs also.

How the carbs were link together just seemed to effect how much power the engine made with part throttling around town. WOT power was the same, so I run the back carb only during light throttle  .

Edelbrock has a tech help line also.

[nqkjw]

I went and Google 440 dual quad edelbrock. Found Edelbrock installation instructions for the CH-28 intake. They like the 1405 carbs with metering rods .070 X .047 with .098 primary jets. Secondary jets are .086 (comes free when you buy a new intake).

36 degrees advance

Says it might be too lean with headers

Those jets and rods sound good to me


The CH-28 Dual Quad intake manifold is designed for 413, 426 (wedge), and 440 c.i.d. Chrysler V8 engines

[Supercuda]

7D,when you set the carbs for running on your 440, follow the installation instructions for the progressive linkage, and use a carb balance gauge like nqkjw suggests, or just use 2 vacuum gauges hooked up to the manifold vacuum ports on the carbs. The idea is to get the idle speed and mixture adjustments on each carb to the point where the vacuum reading on each carb is the same, or "balanced." As far as jetting is concerned, the rules haven't changed; just divide your efforts between the two carbs, and remember that a small change in each equals a big change for the combination. Fuel economy and throttle response will be better with progressive linkage than with direct (1:1) linkage; it comes down to what turns your crank.

[7Dcuda]

7D,when you set the carbs for running on your 440, follow the installation instructions for the progressive linkage, and use a carb balance gauge like nqkjw suggests, or just use 2 vacuum gauges hooked up to the manifold vacuum ports on the carbs. The idea is to get the idle speed and mixture adjustments on each carb to the point where the vacuum reading on each carb is the same, or "balanced." As far as jetting is concerned, the rules haven't changed; just divide your efforts between the two carbs, and remember that a small change in each equals a big change for the combination. Fuel economy and throttle response will be better with progressive linkage than with direct (1:1) linkage; it comes down to what turns your crank.

Thanks Supercuda......unfortunatly I dont have the installation instructions that came with the linkage, it was already installed when I bought the car.  I've looked in the Tech. section of the edelbrock website for info. on this subject but didnt find any.  Guess I'll call Edelbrock and see what I can learn.

[Changin Gears]

The street hemi came with progresive linkage on the AFB's and they work great.  A 1 to 1 linkage makes for a very touchy throttle during normal driving (worse with a stick shift).