Carter AFB/340 Tuning

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skybolt

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Would like info on a good starting tune, metering rods/springs and jet sizes. Getting ready to rebuild carb and would like to be somewhere close.

Carter Performance Series 9636SA-625cfm
Edelbrock RPM air gap
Mild street hydraulic????
340 w/stock heads and bottom end
904 manual reverse pattern w/stock converter

Thanks guys:scratch:
 
If it is a Carter AFB then you can use an Edelbrock tuning kit which comes with a book and an assortment of jets/rods/springs. If what you have is an AVS you will have to use the AFB/Edelbrock flat rod caps.

If you run with heat blocked off on the intake you will need to run richer. If it is not blocked off leaner. If you run a 180 degree thermostat or a 190 that will also have an effect. Edelbrock also sells an assortment of accelerator pump nozzles which will fit the AVS, AFB, and Edelbrock carbs.
 
ramcharger said:
Wish I could help but I'm a Holley guy. :)
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Thanks, I am to and will probably switch to a holley or demon at some point. Don't have enough $$$$ to do everything at once and wanted to tune the carb I have for the time being. Thanks for the honest reply!
 
Looks like 340s has some great info for you. :) I also agree about blocked/not blocked, richer/leaner.

I don't BS anyone here. If I don't know I'll say so. No one knows it all and I most certainly am not a exception. I learn from everyones input as well as my own experiences. That's what makes this such a kick *** site.
 
On my old 1973 Duster 340-4spd-4.10sg I ran a Carter #9636 for a while. I ran .104 primary jets/.101 secondary jets with 68/42 rods and the orange 5" springs due to my MP508 cam. It also had 2.02 valve heads, Performer RPM manifold and headers.

It was a good running very responsive carb but I switched to a tweaked 850 cfm TQ later to have the great response from the small TQ primaries and the top end power gained from the large 2-1/4 secondaries.

Carter AFB's are easy to work on and tune so buy a strip kit if you really want to fine tune it. The Edelbrock stuff will work fine with it.
 
Thanks MY340. That sounds like a good place for me to start. Will probably need different metering rod springs as I probably don't have as much camshaft as the MP508. I don't have a clue as to what camshaft I have. I will measure the lift when I tear it down to put the RPM air gap on.
 
skybolt said:
0.73x0.37 0.73x0.42 ****0.73x0.47**** 0.73x0.52? Metering rod springs???, Secondary jets???. Either trying to be a smart *** or don't know. Looking for a little more specific info.
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thats all you get.
Find someone else to help then from here out partner, maybe they'll enjoy getting attitude from someone who's 'asking' for help.:clock:
 
Sorry 1wild&crazyguy. Ramcharger cautioned me about the dangers of PWI (Posting While Intoxicated).Guess I need to take his advise more seriously. I have learned much from this forum and probably need to think a little more before posting. You see I graduated with honors from Smartass University. Do love your handle from Saturday Night Live. Please accept my opologies for the rude comment.
 
accepted.

Really, try cruising 1st to get the rod size right, these thngs tend to be lean out of the box, at least was on a 340 cam'd 318.

My rule of thumb for these carbs [600-625 afb/eddy] is to set them up like the torker version which was what I was referencing with the 100-73/47 deal
springs n such need driving to figure out.jmo

good luck.
 
Thanks much. Hey we're just a couple of wild and crazy guys. lol
:cheers:
1wild&crazyguy said:
accepted.

Really, try cruising 1st to get the rod size right, these thngs tend to be lean out of the box, at least was on a 340 cam'd 318.

My rule of thumb for these carbs [600-625 afb/eddy] is to set them up like the torker version which was what I was referencing with the 100-73/47 deal
springs n such need driving to figure out.jmo

good luck.
Click to expand...
 
I know that the "Calibration Reference Chart" in the manual doesn´t make any sence at first sight, but please study it carefully and you should get the hang of it.
When you look at the dotted # on the chart you´ll find the corresponding # on the opposite leaf where it refernce to the # for jets and metering rods that 1wild&crazyguy mentioned in his first post.
 
You know, before changing anything I would run it. Contrary to popular belief, they really aren't that lean from the box for a mild big port engine. The only thing I do, without running and tuning it first, is screw in a couple size bigger secondary jets, for the "just in case" factor.

In a small port engine they tend to be a tad on the lean side.
 
I have the original Carter AFB 9636SA (625 CFM Chrysler) manual and could scan it for any of you who wants it emailed. The out-of-the-box jets were 120-398, (.098 primary), 120-398, (.098 secondary), rods were 16-7060 (.0700/.0600) , and springs were Natural 3.0 oz. (Summit Racing doc says Plain which is 8"). The float level was stated as 5/16 " float-to-gasket for the stock .101 inlets with spring loaded needles. Edelbrock says 7/16" and many argue that this is what it should really be for all AFBs. Hope this helps. I also wrote a little Visual Basic application where you can plug in the jet and rod values and it will calculate the cross sectional area and give you percentage of increase/decrease between rod steps (Will happily donate to the cause).
 
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