What's the Difference in Carbs- A/C vs. NON

[HeavyFuel]

Wondering why A/C cars got different carbs than non-a/c cars.

And....if an A/C carb (Carter AVS 4429S) gets put on a non-a/c car.....will it run 'wrong'?

[A383Wing]

mainly different jet size and possible metering rod sizes are different from AC carbs & non-AC ones...and not that much of a difference between the 2 set-ups

engine will not run "wrong" with either carb...it would probably be closer than a "new carb outta the box"

[HeavyFuel]

Ok...thanks.

Still struggling with my carb.   Someone messed with it back in the day, I think in an attempt to get better mileage.   Smaller jets were put in, and who knows what else was changed.     I changed the primary jets back to .101 as spec'ed, but I might just start with a fresh carb.

[Dino]

What problems are you having?  It would be a shame to have to get another carb.  I'm in favor of fixing what is there, as long as it's within proper range of doing so of course.

[A383Wing]

I agree...fix what ya got if possible....the only changeable items would be jets & metering rods....which are still available and cheaper than a new carb

Bryan

[HeavyFuel]

Bad stumble on acceleration, the engine basicallly won't take gas very fast, and when I give it too much, I get a stumble and a backfire throught the carb.


You've chimed in when I've posted about his on a couple other threads.....I still need to try a few things and report back.  Limit my mech advance, advance the initial timing, richer mixture, etc...  

Floats are right, new accel pump.    I removed the lead from the factory set mixture screws on the AVS, so I'm gonna dick with those a little.  Getting late in the season though, so I'll probabaly have to wait until spring.    

[A383Wing]

if yer distributor advance and initial setting are off, changing carbs ain't gonna cure yer problem...just sayin'

Bryan

[HeavyFuel]

I'm hoping that it is the timing.....easier fix.    I'm gonna try out that FBO plate that slips under the advance weights and reduces the mech advance.  I'm shooting for 18* mech, 15* initial, and after that see where the vacuum needs to be.

Also having trouble with the choke coming off all the way in the cooler weather.   I'm considering opening up the crossover block offs in the manifold gasket.


It's always something, but man I'm learning things.   

[375instroke]

A/C carbs have a thermostatic air bleed on top.

[HeavyFuel]

A/C carbs have a thermostatic air bleed on top.

Are you talking about this?

[375instroke]

I think that may be it, according to the FSM, but funny thing is, I have a 4618S carb, '69 440 AT non-AC, and it has that on it.

[HeavyFuel]

 

My 4429s, a 440 A/C auto carb, doesn't have it.