How to read carb calibration chart?

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I’ve learned a lot from this thread. Hopefully sometime this week I can order a few parts and find some time to piddle with it. I’ll come back in here and post what I do.
Thanks guys.
I think the metering rods are about 12 bucks and a set of Springs is around $9 if I'm not mistaking.. Remember don't let us cyber spend too much of your money... that likes to happen out here...
 
I think the metering rods are about 12 bucks and a set of Springs is around $9 if I'm not mistaking.. Remember don't let us cyber spend too much of your money... that likes to happen out here...

Before you know it you'll be buying 55 gallon drums of blinker fluid because some Guru on here said it was a good idea...
 
I think the metering rods are about 12 bucks and a set of Springs is around $9 if I'm not mistaking.. Remember don't let us cyber spend too much of your money... that likes to happen out here...
Looking through Summit I found one set of Edelbrock rods for $15 and a Summit set for $7. A pack of springs is $10 and a pair of jets is $8. Crazy how expensive these little pieces are, but if they’ll make the carb stop flooding my oil and making the Lost island monster stop following me around, I think it’s worth it. I’m going to keep looking around for a wide band because I feel like I can get one cheaper than $212
 
Something to ponder, thin air filters for hood clearance, sets lid right on choke air horn,restricting air/flow, something I discovered the hard way.
A thick K&N is already in my cart lol. Might have to trim the hood a little but it’s already been hacked by the PO so I don’t care.
 
Looking through Summit I found one set of Edelbrock rods for $15 and a Summit set for $7. A pack of springs is $10 and a pair of jets is $8. Crazy how expensive these little pieces are, but if they’ll make the carb stop flooding my oil and making the Lost island monster stop following me around, I think it’s worth it. I’m going to keep looking around for a wide band because I feel like I can get one cheaper than $212

Here's where I differ with most the others, and actually agree with J-Par here. Yea, nuts. eh. :realcrazy:
If you haven't already, go buy a note book or clipboard with a stack of paper.
Save your dough on the WBO2 and spend the time on systematicly tuning.
(I expect at least one big x at the bottom of my post now. Go ahead I can take it.
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What I'm talking about is this. You glance down at the AFR gage on the dash and it shows 14.1 or 13.3 or 15. What does it tell you? Does it tell you the engine is making more power? No.
Its only useful if you can associate the reading with a specific condition, a change you made to the carburation, and a change in performance.

Systematicly trial and error for performance.
Do all the steady conditions first. Start at the idle and work up. If its crappy at idle then the engine is going to have to clear up before it can respond to additional throttle. So idle and off idle are your foundations.
Performance here is going to be demonstrated by running fairly clean exhaust output and how little throttle is needed to get into first gear without stalling. Work with initial timing, idle mixture and float settings. The step up springs should not be involved at idle.

Follow with confirmation of off-idle. performance is being able ot get into gear and very slowly accelerate with no hesitation. If that's good, then with more normal acceleration (for public streets) and make sure the pump shot is not too much or too little for this basic job.

Then you can test out steady driving at various speeds. The fuel ratio at steady highway speeds is determined by the rod and jet combination. A change of the rod or jet per the chart should let you test how lean it will run on the highway. When starts to rev and die - its too lean!

If you have access to the strip or dyno you can also test wide open throttle in 3 or 4th. AFR is controlled by the jets. Change jets for the best mph through the lights.

All the above is effected by timing. If you change timing at a given rpm and condition, then retest before change fuel mixture for that condition.

Once all that is tuned, then concentrate on transition conditions. That is part throttle (springs) and opening the throttle quickly from low rpm (pump shot). Reality is you may have to go out of sequence. You will almost certainly have to make repeats. How many depends on how much interest and persistance you have in tuning it in.

Good luck!
 
Looking through Summit I found one set of Edelbrock rods for $15 and a Summit set for $7. A pack of springs is $10 and a pair of jets is $8. Crazy how expensive these little pieces are, but if they’ll make the carb stop flooding my oil and making the Lost island monster stop following me around, I think it’s worth it. I’m going to keep looking around for a wide band because I feel like I can get one cheaper than $212

Look on Ebay. There's a seller called Ninja Fuel Systems. They are located in Georgia. I use them a lot.
 
Something to ponder, thin air filters for hood clearance, sets lid right on choke air horn,restricting air/flow, something I discovered the hard way.

Absolutely. Wouldn't hurt a thing to run without the air cleaner just to see "what you get".
 
First thing to do on an Edelbrock imo is set the float level. They can be finicky and don’t like mis adjusted floats. Second is get the thick insulator gasket Edelbrock sells, do not substitute here. Third is order a “calibration kit” from Edelbrock for that specific model carb. There are many different kits and they are carb specific. Third is make sure you are reading the correct chart for that model carb, again Edelbrock has a chart for every model and they are different. Forth, get a note pad and document changes to the carb and how the engine runs. All of this is assuming the carb is clean and has all box stock settings. They respond to changes pretty well. Write everything down.
 
I’ve bought a calibration kit for my carb and an AEM wideband gauge. Hopefully I’ll have time to play with it sometime soon.
 
Awsome.
Two suggestions.
1. Tune for best performance. In other words don't worry about the AFR number, much less aim for any AFR number. Use the AFR to see the effect of changes to carb restrictions under various conditions.

2. Ignore this chart. It is wrong.
upload_2020-2-27_15-50-1.png


No idea what it's based on or its just a major editing goof. Doesn't matter. It flies in the face of decades of engine research by industry, academia and the military.

If you want to see a legit relationship of Fuel/Air to engine needs, this one is good.
upload_2020-2-27_16-1-12.png

from Walter B. Larew, Carburetors and Carburetion

More about that graph in Wideband
 
I don’t know how the hell this happened because I’m always extremely careful with these little parts, but I think this could’ve been part of my issue.
68D12862-A23C-4D8B-91D4-59CFEA3DC1EA.jpeg

I’ve re-jetted the carb and swapped out the metering rods according to the chart. I have a few more things I need to do before I start the car though so I’ll keep updating.
 
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