Carburetor wizard…or someone that knows more then me

[Cheapsunglasses]

The plugs are too cold. Should be a NGK 5. Low speed cruise is controlled by the idle cct, not the met rods.
If the engine is modified in any way [ different cam, intake, headers etc ], it can change the transfer slot running position which will alter the delicate low speed balance.
Stupid question: have you made sure the choke is fully 'off'?

Thanks! Im thinking of changing to champion rc12yc, that’s what 440 source sells, but I had a bad set of champions once and kinda made me bitter towards them. I saw someone on one of the forums recommend ngk so I used it

Not a dumb question at all. I’ll have to look at my carb to make sure I did it, I hate chokes so I wire mine open, can’t have a choke close when it’s not suppose to close when it can’t close

 

[RJRENTON]

The plugs are too cold. Should be a NGK 5. Low speed cruise is controlled by the idle cct, not the met rods.
If the engine is modified in any way [ different cam, intake, headers etc ], it can change the transfer slot running position which will alter the delicate low speed balance.
Stupid question: have you made sure the choke is fully 'off'?

Typically, the Carter #4327S, because its an emission control carb and it has an off idle air bleed circuit, it is usually LEAN off idle. As stated, the primary metering rods and jets do not control the idle and off idle fuel transition circuits. ALL the idle and off idle fuel comes from the primary booster venturii assemblies. There are two fixed closed throttle plate drilled air bleeds, in the main body casting, accessable from the bottom of the carb. It is possible that some carb "expert" has plugged these fixed air bleeds, which would account for your high (rich) idle/low speed Air-Fuel ratio. The alternative cause, someone may have drilled the 0.035" diameter idle fuel restriction in the primary booster venturii assemblies larger. Just a few additional talking points......
BOB RENTON

 

[Cheapsunglasses]

Typically, the Carter #4327S, because its an emission control carb and it has an off idle air bleed circuit, it is usually LEAN off idle. As stated, the primary metering rods and jets do not control the idle and off idle fuel transition circuits. ALL the idle and off idle fuel comes from the primary booster venturii assemblies. There are two fixed closed throttle plate drilled air bleeds, in the main body casting, accessable from the bottom of the carb. It is possible that some carb "expert" has plugged these fixed air bleeds, which would account for your high (rich) idle/low speed Air-Fuel ratio. The alternative cause, someone may have drilled the 0.035" diameter idle fuel restriction in the primary booster venturii assemblies larger. Just a few additional talking points......
BOB RENTON

The had emissions in 67?

 

[Cheapsunglasses]

I finally got around to looking at the carb this evening, thanks @Geoff 2 for asking about the choke, sure enough I didn’t have it wired open

While the car is cool, I’m going to go ahead and take the top off and check the floats too, thanks everyone!

 

[Cheapsunglasses]

I’m a little confused here. It says it’s supposed to be a 2 step rod, 16-164. But when I look up 16-164, it says it’s .0625x.060x.051. Thats 3 numbers, am I misreading it?

 

[RJRENTON]

I’m a little confused here. It says it’s supposed to be a 2 step rod, 16-164. But when I look up 16-164, it says it’s .0625x.060x.051. Thats 3 numbers, am I misreading it?

View attachment 1303794

View attachment 1303796

IMO.....no, don't think so. A 3 step metering rod has a power step (smallest end diameter), intermediate step (mid diameter) and cruise step (largest diameter). The difference in 2 step vs 3 step will be the overall length of the rod and the overall length of the step up piston and, in my experience, the 2 step assembly will use a flat piston cover plate and the 3 step assembly will use a slightly domed cover plate. I think the 3 step metering rod and piston assembly gives a smoother transition from cruise step to power step in therms of the air-fuel ratio. Obviously, the step up piston spring will influence the operation of WHEN, in terms engine vacuum, the metering rod and piston assembly will move up or down. Which method is best or better? It determines the application. I would think a racing application would use a 2 step assembly. Conversely, for a street driven application, a 3 step assembly would/should give better MPG or smoother operation. What are your requirements?
BOB RENTON

 

[Cheapsunglasses]

IMO.....no, don't think so. A 3 step metering rod has a power step (smallest end diameter), intermediate step (mid diameter) and cruise step (largest diameter). The difference in 2 step vs 3 step will be the overall length of the rod and the overall length of the step up piston and, in my experience, the 2 step assembly will use a flat piston cover plate and the 3 step assembly will use a slightly domed cover plate. I think the 3 step metering rod and piston assembly gives a smoother transition from cruise step to power step in therms of the air-fuel ratio. Obviously, the step up piston spring will influence the operation of WHEN, in terms engine vacuum, the metering rod and piston assembly will move up or down. Which method is best or better? It determines the application. I would think a racing application would use a 2 step assembly. Conversely, for a street driven application, a 3 step assembly would/should give better MPG or smoother operation. What are your requirements?
BOB RENTON

Thanks, yes I know the benefits of 2 step vs 3 step. But what I’m confused about is it says it a 2 step, but it gives 3 numbers on the factory metering rod.

It says .0625x.060x.051. If it was a 2 step, wouldn’t it just be .0625x.051?

And if I’m not mistaken then new edelbrocks use a 2 step rod, and you can’t get 3 step rods, so you have to use 2 steps to tune the carb

 

[Don Frelier]

The plugs are too cold. Should be a NGK 5. Low speed cruise is controlled by the idle cct, not the met rods.
If the engine is modified in any way [ different cam, intake, headers etc ], it can change the transfer slot running position which will alter the delicate low speed balance.
Stupid question: have you made sure the choke is fully 'off'?

I had some lean rods in my AFB and it ran okay until it got fully up to temperature. When I pulled into the parking lot at work after 25 minutes it quit. Didn't want to start. At the end of the day it fired right up and I drove it home. Put the rods I had been running and it was back to normal.
Your going to have to convince me that the rods don't influence cruise mixture.

 

[Cheapsunglasses]

Last night I checked my float levels, they were a little off so I adjusted them, carburetor mike’s website said 5/16 at rest and 11/16 at drop. I also made sure my choke will never close. I’m not sure if I’ve mentioned this, but I’ve never tuned anything, I’ve somehow been lucky enough stuff works on the few cars I’ve worked on, until this car. I have no idea what I’m doing!

It was a little late when I got everything back together, so I waited until the morning. I drove at every gear, every speed 10-100mph. I get the same readings, 10.7-11.3afr at cruise, 12s at light acceleration, 13-14 at heavy acceleration.

1. Do I need to change my plugs to a hotter plug before continuing?

2. Is this even the right carb for a 350 hp 440, with 440 source heads, magnum manifolds, and a strange offenhauser intake that nobody likes?

3. If this is a good carburetor for my car, what kit do I use to try to make it work?

Thanks!

 

[Frank Mopar]

Looking at the timing marks on the strap shows your timing is off.

 

[Cheapsunglasses]

Looking at the timing marks on the strap shows your timing is off.

By off do you mean too retarded or too advanced?

 

[Geoff 2]

Cheap,
Here is what I would do. Fit the NGK 5 plugs, as discussed. There could be many problems with ign timing with old engines & unknown history. Centri weights in the dist maybe binding, springs stretched, vac adv not working because it is binding up or diaphragm has failed. A failed VA unit will cause rich cruising. Remove the dist cap & suck on the VA fitting; you should see the plate move. All things to check in an orderly fashion. I would set initial timing to 12* BTDC.

On the 2 step/3 step rods. Carter/Chry built engine combinations where they were able to exactly specify metering requirements. As Edel carbs are a 'universal' one size fits all deal, there was no practical way to use 3 step rods that would work with every engine combination. Hence the smart move to use 2 step rods.

 

[Cheapsunglasses]

Cheap,
Here is what I would do. Fit the NGK 5 plugs, as discussed. There could be many problems with ign timing with old engines & unknown history. Centri weights in the dist maybe binding, springs stretched, vac adv not working because it is binding up or diaphragm has failed. A failed VA unit will cause rich cruising. Remove the dist cap & suck on the VA fitting; you should see the plate move. All things to check in an orderly fashion. I would set initial timing to 12* BTDC.

On the 2 step/3 step rods. Carter/Chry built engine combinations where they were able to exactly specify metering requirements. As Edel carbs are a 'universal' one size fits all deal, there was no practical way to use 3 step rods that would work with every engine combination. Hence the smart move to use 2 step rods.

Thank you! I was using a distributor With a vacuum advance, but it failed, so I’m using a mechanical advance Mallory dual point.

 

[AR67GTX]

I went through some of this last winter on the same Carb. Once I got it all squared away it runs strong. But I don’t have an A/F meter hooked up. Maybe something in it will help.
Carter 3-step metering rods and corresponding jets/springs

 

[Cheapsunglasses]

I went through some of this last winter on the same Carb. Once I got it all squared away it runs strong. But I don’t have an A/F meter hooked up. Maybe something in it will help.
Carter 3-step metering rods and corresponding jets/springs

Thanks! Well reading through kinda help. Helped me decide I might just want a brand new carb, that they make kits for, so I don’t have to hunt for things.

 

[Cheapsunglasses]

The parts store didn’t have ngk 6, so I went with the equivalent champion. Started it up to check the timing, it was difficult to start, then when I got it to start it idle crappy, after advancing the timing 4 degrees it was better, but now it’s missing on a couple cylinders

 

[Cheapsunglasses]

I’m don’t know a lot about tuning, but if changing timing and plugs makes things worse, it’s not ignition causing it to be too rich

 

[Cheapsunglasses]

I went inside, had lunch, let everything cool down. I went back out, moved the wires some, I don’t think it’s missing as bad. The exhaust note is still not as smooth as with the ngk 5 and 10 degrees initial. And I took it for a road test, pulled hard, did good, but I still have the same 10:1 cruising, 12:1 moderate acceleration, 13:1 heavy acceleration numbers.

 

[RJRENTON]

I went inside, had lunch, let everything cool down. I went back out, moved the wires some, I don’t think it’s missing as bad. The exhaust note is still not as smooth as with the ngk 5 and 10 degrees initial. And I took it for a road test, pulled hard, did good, but I still have the same 10:1 cruising, 12:1 moderate acceleration, 13:1 heavy acceleration numbers.

The heat range of the spark plugs SHOULD NOT affect idle quality, at least initially. What was the gap setting and type number of the plugs just installed? Its possible that the gap setting was inadvertently changed during installation or the plug was damaged (cracked insulator). Spark plug coloration is the easiest to determine correct mixtures and spark advance characteristics but is easily influenced . Are you sure that the plug wires were not damaged during removal or installation, especially if the wires are suppression core. IMO....the A/F ratios are somewhat important but not as, at least initially, as others profess. Time slips or dyno runs (engine performance), corrected for temperature and air density would be the best determination. A/F ratios are transitory and should be compared side to side (both banks) for accuracy. Only readings of one side are, IMO, are useless, due to distribution diffrrences. You would be better off reading Exhaust Gas Temperature (EGT) of each cylinder, to determine uniform mixture distribution and spark advance characteristics, but is not realky practical for the average person, due to the equipment involved. Your cam and compression ratio are big influencers of low RPM operation. Do you have any b4 and after numbers to support your comment of: "pulled hard" and "did good"....as those are subjective.....just taking out loud.....
BOB RENTON

 

[Cheapsunglasses]

Champion rc12yc at .035