Carter AVS Ports unknown

[Stoffauge]

Hey guys.....got a rebuilt 383 with a
Carter AVS 4 Barrel Carb but I am not 100% sure for what connection all the ports are and where the vacuum hoses have to go to and come from etc.

Made some simple drawings with numbers and I hope somebody can light up my way......

Thanks in advance

EDIT: Sry if my post is in the wrong section, saw it too late

 

[saforwardlook]

Your positive crankcase vent (pcv) outlet is correctly labeled, 2 is for your distributor vacuum advance can, 3 is for your choke pull-off, 4 is for your air cleaner control on the underside of your air cleaner, the bowl vent labeled breather is correctly routed to your breather, and your fuel line has a non-stock adaptor on it.
Hope all runs well.

 

[Stoffauge]

Your positive crankcase vent (pcv) outlet is correctly labeled, 2 is for your distributor vacuum advance can, 3 is for your choke pull-off, 4 is for your air cleaner control on the underside of your air cleaner, the bowl vent labeled breather is correctly routed to your breather, and your fuel line has a non-stock adaptor on it.
Hope all runs well.

Perfect answer thanks a lot. I am sure you know what number 1 is for too right? Does the non stock fuel adaptor make any difference? The air cleaner I got with the car doesnt have any port for the number 4 hose.....should I better get one that does have it? Does look a bit weird though the air cleaner without any ports....

 

[saforwardlook]

What is think is your number 1 is your choke pulloff vacuum diaphragm that connects to number 3 port on the base of the carburetor. If your air cleaner doesn't have a temperature control switch (it is just a bimetal temperature control switch) mounted on the underside, you can just plug off number 4 port with a rubber vacuum plug since you don't have a heated air controlled snorkel air flap(s) then. The air door(s) will always be open then to allow airflow as normal (they are only activated closed under vacuum at colder temperatures). This feature is to utilize a heated air shroud mounted on the driver side exhaust manifold to funnel heated intake air into the carburetor under cold conditions to better atomize the air/fuel mixture for better warm up performance/driveability and lower emissions.

Many times the heated air shroud is missing and sometimes also the bimetal switch that controls air flow under cold conditions is gone too. So just plug off the port on the carburetor with a vacuum plug and call it a day. The air flap(s) will always be open and there would be no heated air for warm up purposes.

That fuel line adaptor will accept a rubber hose with a clamp to allow fuel into the carburetor from the fuel pump. From the factory, there is a steel line from the outlet of the fuel pump routed up to the carburetor and the fitting on the end of the steel line would normally attach to the carburetor with a factory type secure fitting. Using a rubber hose to go from the fuel pump to the carburetor is not a safe method of getting fuel up to the carburetor, as any failure of the rubber hose would spray fuel potentially on a hot engine/exhaust manifold and cause a real fire hazard. Get the correct factory line and carburetor fitting I would advise (there is often a fuel filter mounted just after the fuel pump in some cases down low on the engine, with short rubber hoses, and then to the metal line continues up to the carburetor but those are a factory set up and should not be so much of a hazard where the fuel filter is mounted down low.

 

[Stoffauge]

Hello again.... at first a big thanks for your answer. Things are getting clearer and clearer because of you .

I do have an exhaust manifold with this heated air shrout where you connect a big hose which goes to the air cleaner housing (normally). The housing I got doesnt have this port neither it has the bimetal switch for the small vacuum hose from carb port number 4. So actually this car had a different air cleaner housing I guess with the two ports right? Should I get one thats closer to original or just take it as is in your opinion/ with your experience?

Fuel inlet: I do totally understand the bigger risk of a rubber fuel line from pump to carb. I got the car with a dirty tank and thats why the prev owner started it out of a gas canister and used a rubber hose (car was barn find , 29 years of standing).

I´ve seen engines (google pictures) that just use a small rubber piece with a filter in it but the biggest part is made of steel. I guess for the long run I should go back to steel. So I guess the distance from tank to fuel pump should be steel too? Haven´t seen it original thats why I am asking sry.....

The car came with a single snorkel air cleaner housing. Is it recommended to stay with a single snorkel or may I use a dual one too? Looks more synchronous... D )

Pretty sure I will have more questions if its ok......you´re such a great helper with nice explanations! Much appreciation!

 

[saforwardlook]

Glad to help sir.

Since you already have the shroud on the driver side manifold, it is up to you whether you want to convert your air cleaner to one that incorporates the heated intake air capability for improved driveability on colder days. If you don't drive your car much in the winter season or at all, you might decide to forego any worries about getting such an air cleaner assembly. The improvements were not large in driveability, but they helped a little in preventing deep stumbles and pass outs when accelerating during cold operation. But I should add that proper carburetor choke setting are also critical to this aspect of cold driveability, so make sure an expert has set the choke setting properly or reference a service manual for those settings if making them yourself (this is an aspect where some experience helps a great deal in getting them correct - so reach out to such an expert in Germany by talking to other members on this site from your area perhaps). If your car is driven mostly in warmer summer months, there would be little reason to change from your present system. You could choose either a dual snorkel or a single snorkle air cleaner, as either one was available in production for these vehicles with heated air capability. For vehicles with the 383-4 fuel system, the typical air cleaner released from the factory was a dual snorkel one, which does look more sporty too. Again, your choice.

Perhaps the fuel line issue could be understood better by accessing this thread on this site since the same fuel line issues that you have questions about have come up there, and embedded in this thread is a recommendation as to where to obtain the correct fuel line and related parts:

Fuel line path

Member ayilar in that thread has essentially the same fuel system set up on his 1970 Dodge Polara convertible as you have on your vehicle.

If you have further questions, please ask and we can do our best to clear them up.

 

[Snotty]

Does the non stock fuel adaptor make any difference?

It "should" be pointing out straight.

 

[Stoffauge]

Good day sirs.... I´ll check the fuel line thread, thank you. I got one more question before we can close this solved problem. The pcv goes to the carb. One hose from the breather on the passenger side goes to the carb too. fine. But where do the other two ports go to? Got a 3 port breather cap.

I think I read that one goes back to the tank to vapor liquid seperator? So just one is missing..or if I get the picture right it goes somewhere around the air cleaner region?

Best regards and thanks 10000x!

 

[saforwardlook]

Good day sirs.... I´ll check the fuel line thread, thank you. I got one more question before we can close this solved problem. The pcv goes to the carb. One hose from the breather on the passenger side goes to the carb too. fine. But where do the other two ports go to? Got a 3 port breather cap.

I think I read that one goes back to the tank to vapor liquid seperator? So just one is missing..or if I get the picture right it goes somewhere around the air cleaner region?

Best regards and thanks 10000x!

View attachment 365082

The large breather hose goes to the side of the air cleaner where there is a large hose attached somewhere on the side of the air cleaner that varies with the model year vehicle/air cleaner assembly you have. The line labeled "carb" goes to the carburetor bowl vent as labeled correctly in your photos. And if your car indeed has a California emission package, then there is a line coming up the fender apron (inner fender) in the vicinity of the breather area and that metal line routes excess fuel tank vapors into the breather as well. The bowl vent also routes vapors into the breather as well from the carburetor to prevent excess HC emissions in the atmosphere that when combined with nitrogen oxide emissions causes smog in congested metropolitan areas. Both of these practices lead to excess fuel vapors being stored in the engine crackcase, or in other words, in the engine oil, a practice I don't like. In my case I just leave the bowl vent nipple on the carb open without a hose and same for the vent from the fuel tank if you indeed have that line on your car. Then just plug the two nipples on the breather cap you wouldn't use with rubber caps and just use the large nipple from the side of the air cleaner, as it causes no issues. Or get a single nipple breather. That is what I do on my cars but the choice is up to you.

 

[Stoffauge]

Ok I see. So for my case with my simple air cleaner housing with no ports/bimetal at all I would leave all openings of the breather cap unused I guess. Because actually I thought the breather causes that no fuel vapors stay in the crankcase and in the engine oil and get back to the carb to get burned again. But if you tell my its the opponent than I´ll follow your advise because I dont like that eather. I do now totally understand how that works on this car because of your explanation. Thanks a lot!!

Breather cap: May I just get a nice sporty looking breather cap (like attached below)? Or do I have to close it properly? I will get new Mopar performance valve covers and the breather hole/plugin is closed by manufacturer. I could then just leave it as is and just open the PCV valve ?! What would you do?

Fuel line: Should I cut the fuel line thats come up the inner fender right behind the tank that the vapor gets out below the car? Or how´s the proper way to do it nice and simple?

Great conversation! Sry for my English.At some points I just don´t know the specific words...... Have a great day and thank you again and again and again.......

 

[saforwardlook]

Ok I see. So for my case with my simple air cleaner housing with no ports/bimetal at all I would leave all openings of the breather cap unused I guess. Because actually I thought the breather causes that no fuel vapors stay in the crankcase and in the engine oil and get back to the carb to get burned again. But if you tell my its the opponent than I´ll follow your advise because I dont like that eather. I do now totally understand how that works on this car because of your explanation. Thanks a lot!!

Breather cap: May I just get a nice sporty looking breather cap (like attached below)? Or do I have to close it properly? I will get new Mopar performance valve covers and the breather hole/plugin is closed by manufacturer. I could then just leave it as is and just open the PCV valve ?! What would you do?

Fuel line: Should I cut the fuel line thats come up the inner fender right behind the tank that the vapor gets out below the car? Or how´s the proper way to do it nice and simple?

Great conversation! Sry for my English.At some points I just don´t know the specific words...... Have a great day and thank you again and again and again.......

View attachment 365247

Your understanding of the breather cap is not incorrect so allowing it to breathe is still important. Whether you connect your breather outlet to one on a factory air cleaner is still a good idea as it will minimize the smell of vapors around your car. But the aftermarket one will work too if you don't care about that.

My point with the other ports is that the extra fuel that those two sources add to the engine oil is excessive I believe and should be avoided with the attendant smell issue being even worse around the engine compartment and around the car when the engine is off.

I do not know what model year of car you have and what the fuel tank arrangement is - if yours is a 1971 model there may be a small auxiliary tank mounted just above the back of the fuel tank that captures excess vapors and then sends them up that line to the breather. If you cap off that line at the small capture tank, just be sure there is another fuel tank vent elsewhere or that the fuel tank cap is vented or maybe just leave the vent open assuming no liquid comes out of it. I have not capped off that outlet, but rather just left the line open in the engine compartment. Just be sure that whatever route you take that it is a safe one relative to fire risk.

This early system was just a stop gap system until the charcoal vapor canisters came along in 1973 models I believe that properly took care of excess HC vapors and purged them properly too.

 

[Stoffauge]

Alright. You guessed totally right it´s a 71 Sport Fury and I already removed the small extra tank for cleaning and removing rust etc. So I know what piece you are talking about. I didnt even know that there is a "smell issue" because with newer cars there isn´t. Learned something new again!

After a quick thinkabout I guess I cut the the line somewhere in the front/engine bay area too and let it flow somewhere safe, far from the header. I just have to figure out where it could be. WHat about cutting it at the half lenght and leave the vapors outside somewhere in the middle under the car away from the engine bay?

At first while I am still restoring and dont do longer rides I plug the fuel line port and the carb port of the breather cap and leave the air cleaner port open I guess and see how bad the smell will be. For the long run I´ll get a 1 port breather to connect it to the right air cleaner. I think thats a good compromise.....althought I really like the look of this sporty filter cap I posted above.

Weird that the air cleaner I got now doesnt have any port at all.......just a single snorkel without any other stuff.....

Guess we got it for now....your a great guy. Really appreciate your help!

 

[saforwardlook]

If you removed the small extra tank already, that should be where the line going up to the engine bay inner fender originates, so just leave the line going upfront where it is or remove it all together if you want - nothing will be in it.

When you removed the small extra tank, what did you do with the 4 ports that are on the fuel tank that feed that tank - did you cap them? I guess since the orifices on those ports are so small, no appreciable amount of fuel could escape at once under deceleration conditions that would constitute a hazard anyway if left open or you may already have a vented cap, so perhaps there is no need to worry further. Just double check that those small ports on the back of the fuel tank do indeed have very small orifices in them.

 

[Stoffauge]

Good morning

I removed the tank and the small auxiliary tank for cleaning, removing rust and painting and unplugged all hoses but didn’t do any cutting or whatever because I didn’t even know what this small tank was for . But now I guess I will Install it like it was and just leave the breather fuel line open somewhere safe. Sounds like the best way to me...

So if I got it right and summarize the whole breather is just causing a gas/oil smell when it’s left open with a small sporty filter on top right? And I can reduce that with a 1 port breather that plugs into the aircleaner housing or I close 2 of 3 ports with a plug and keep on unsung my 3 breather cap. No issues with a bad running engine or so. Great.

So nothing to really worry about besides the fuel line that it doesn’t drop . But that’s definitely fixable .

 

[saforwardlook]

Good morning

I removed the tank and the small auxiliary tank for cleaning, removing rust and painting and unplugged all hoses but didn’t do any cutting or whatever because I didn’t even know what this small tank was for . But now I guess I will Install it like it was and just leave the breather fuel line open somewhere safe. Sounds like the best way to me...

So if I got it right and summarize the whole breather is just causing a gas/oil smell when it’s left open with a small sporty filter on top right? And I can reduce that with a 1 port breather that plugs into the aircleaner housing or I close 2 of 3 ports with a plug and keep on unsung my 3 breather cap. No issues with a bad running engine or so. Great.

So nothing to really worry about besides the fuel line that it doesn’t drop . But that’s definitely fixable .

I believe what you are doing with the forward fuel vapor line will be satisfactory.

The breather thing is a bit complex and I am honestly not sure what is the best approach to take since your air cleaner seems to be an aftermarket one rather a factory one in the first place. Here is a more in depth discussion of the entire system including the PCV system that you might want to read over and then make your decisions based on this information. For me the bottom line seems to be that your approach with the aftermarket system might work OK for some time with no real issues. Over the long term, it is hard to project what the effects would be.

Best wishes,

Engine - Breather System