Carter/Eddie AFB question

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mbaird

mbaird

mbaird
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I was messing with my Swinger the other day and decided to slap a 1406 Eddie on it just to see how it performed with a tiny carb . (This is a 408 with W2s , solid roller and Victor single plane intake . ) I set the floats , idle screws and transition slot then instaled it …. Wouldn’t idle unless I opened the idle screws 4+ turns and cranked the throttle screw a few turns .
Hmmm…???
So I grabbed a Carter Competition 750 off the shelf and repeated the process .
Same outcome ! I double checked for vacuum leaks

What simple thing am I missing ?
Ran fine with my Pro Systems 850 on it ….
 
Low vacuum signal from a big cam will put the metering rods in the rich position and you have to give it more air to idle. You can alleviate that by tuning with a vacuum gauge and putting in the appropriate step up springs.
 
RustyRatRod said:
Low vacuum signal from a big cam will put the metering rods in the rich position and you have to give it more air to idle. You can alleviate that by tuning with a vacuum gauge and putting in the appropriate step up springs.
Click to expand...
Changed springs to 4” ( forget color) and confirmed the pistons are down while at idle by opening cover while running .
 
mbaird said:
Changed springs to 4” ( forget color) and confirmed the pistons are down while at idle by opening cover while running .
Click to expand...
Well, that blows my theory all to heck. lol
 
Actually I can’t tell one color from another on Carter/eddie springs . Stupid system !

It’s gotta to be something simple that I am overlooking.
I have run them on my Barracuda in the last year and they are fresh rebuilds .
 
I hope you like to tinker, it usually takes 2 Carters to run properly with any amount of cam. lol
Idle is one thing, transition is another. Carter makes it hard to achieve both. very sensitive to vacuum pulsation
 
Try some bypass air. You can get it from the air cleaner to the carb and adjust the flow rate with a restriction or PCR valve. The idle channel restrictor maybe too small to let enough air through the idle circuit to sustain a high enough idle.

The 1406 has a lean calibration so you may need to open up the IFR. You can also drill and tap the primary cluster for adjustable holley air bleeds.
 
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The 1406 doesn't just have a lean condition. It IS lean. It's the economy version, so it's very lean. The 1405 is the performance version. There are some pretty significant differences, too.
 
RustyRatRod said:
The 1406 doesn't just have a lean condition. It IS lean. It's the economy version, so it's very lean. The 1405 is the performance version. There are some pretty significant differences, too.
Click to expand...
The calibrations make it lean. Whether that's IFR IAB's MAB's or MJ's it makes no difference as that is what sets the flow rates for either air or fuel.

Change the calibrations and change what the carb meters.
 
I have some 1405s as well . I was thinking about that . I will try one of them . Really don’t want to drill the bleeds on the 1406 while just messing around .
But the 750 competition shouldn’t be calibrated lean .
 
mbaird said:
I have some 1405s as well
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Try them or just swap the primary boosters.

If you can find an early genuine Carter performance 625 and just use the boosters in the eddie main body.
 
mbaird said:
I have some 1405s as well . I was thinking about that . I will try one of them . Really don’t want to drill the bleeds on the 1406 while just messing around .
But the 750 competition shouldn’t be calibrated lean .
Click to expand...
Is it a 1407 Eddy? They had tons of issues. I have one I couldn't get right no matter what I did. Google it. lol
 
9635SA

image.jpg
 
That looks to be a later Federal Mogul Carter carb and most likely will have the Edelbrock equivalent calibration. Pull the boosters and check the emulsion tube set up. The real Carters will have a tube with a series of small holes along 2 sides of the tube.
 
[1] The first thing to check is that the passages in the AFB base are covered by the gasket/manifold flange. If not covered, you will have a large air leak which would explain your some/all symptoms.
[2] Engine idling, remove the PCV & make sure it is pulled in. If not 'in' or vibrating it is adding varying amounts of air & playing havoc with idle air metering.
[3] The cheap [ & simple ] fix for [2]: get a 3/8" diam bolt & cut off a 3/8" length of it. Drill a 1/8" hole through it; push into the PCV hose. You now have a functional PCV.
[4] The ProCrap 850 probably had adjustable by pass air, & this carb may need it too.
[5] Not time for drilling holes....yet.
[6] Single plane, & a Victor, will provide less vacuum & exacerbate the problem.
[7] What are the cam specs & timing at idle? See below.

img307.jpg
 
Bewy said:
[1] The first thing to check is that the passages in the AFB base are covered by the gasket/manifold flange. If not covered, you will have a large air leak which would explain your some/all symptoms.
[2] Engine idling, remove the PCV & make sure it is pulled in. If not 'in' or vibrating it is adding varying amounts of air & playing havoc with idle air metering.
[3] The cheap [ & simple ] fix for [2]: get a 3/8" diam bolt & cut off a 3/8" length of it. Drill a 1/8" hole through it; push into the PCV hose. You now have a functional PCV.
[4] The ProCrap 850 probably had adjustable by pass air, & this carb may need it too.
[5] Not time for drilling holes....yet.
[6] Single plane, & a Victor, will provide less vacuum & exacerbate the problem.
[7] What are the cam specs & timing at idle? See below.

View attachment 1716287684
Click to expand...
Using a 4 hole gasket on a 4 hole spacer . Although I was unaware of any holes in baseplate on these carbs .

Disconnected the PCV and capped the port … no change .

Cam is 246/250 on a 108. .648 lift

I have run my 800 AVS2 on this engine with no issues.

And I have run the 1406 ,1405 and Competition on other engines successfully .

Just seems like I am overlooking something basic .
 
What is the idle timing?
Did you read the link in post #16/
And this:

img267.jpg
 
I have experimented with several different intial settings, mechanical curves and VA curves/starting points .
This engine does not like much more that mid 20s total at below 2000 rpm’s. I was getting some trailer hitching between 1500-2500 and breakup over 3k . I have softened the curve and disconnected the VA for the moment . Right now I am at 18* inititial @ 1000 rpm increasing to 22-24 by 1500 region and 32 total by 3k.
 
I agree with the spring colors, I learned to put tape on mine to ID them. I also wrote what leanest to richest is on the back.
Plain is the richest I believe, then pink, then orange is stock.
**edit** I actually had to set them up side by side and then use an online picture to tell which is which. THEN I labelled the damn things.
mbaird said:
Actually I can’t tell one color from another on Carter/eddie springs . Stupid system !

It’s gotta to be something simple that I am overlooking.
I have run them on my Barracuda in the last year and they are fresh rebuilds .
Click to expand...
 
mbaird said:
I have experimented with several different intial settings, mechanical curves and VA curves/starting points .
This engine does not like much more that mid 20s total at below 2000 rpm’s. I was getting some trailer hitching between 1500-2500 and breakup over 3k . I have softened the curve and disconnected the VA for the moment . Right now I am at 18* inititial @ 1000 rpm increasing to 22-24 by 1500 region and 32 total by 3k.
Click to expand...


I asked this before (I thought I did anyway)but didn’t you dyno your engine?

If so, where does peak torque begin and how far does it maintain peak torque?

Because 22-24 below peak torque is a lot. And I suspect you are at full timing during peak torque which is a power killer.
 
mbaird said:
Right now I am at 18* inititial @ 1000 rpm increasing to 22-24 by 1500 region and 32 total by 3k.
Click to expand...

I once had a 292/292/108 in my 367. That I measured at 248/249@050
I ran it with every carb in my arsenal. No problems but, every one required a different amount of bypass air. All of them ran fine with as little as 5* Idle timing. Altho I ran in the 22>14 window, which provided enough T-slot exposure to get rid of the Tip-in sag.
If you can't get yours down that far I would suspect internal friction. In my case I had to take the engine down, add ring-gap and a tad more skirt clearance. Badaboom.

Have you tried 12>14 Idle-Timing?
 
I will adjust the VA can to start at around 11-12” and reconnect later .
I have reinstalled my 850 4150 for now .
The Carter was an exercise for the moment but I ran out of time to mess with it for now .

Its interesting how many mods there are for AFBs/AVS’s that most are unaware of . I wish there was a source for annular discharge boosters for them .
Edelbrock refuses to sell them individually.
 
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