Engine: Carburetor Automatic Choke Heat Tube

[345 DeSoto]

On a '56 4V intake manifold. Is the tube that the automatic choke attaches to, that extends into the exhaust cross over, suppose to be open on the end in the cross over?

[skyway]

I think it should be a loop; opened to air on both ends, but closed to internal gasses?
Exposure to exhaust gasses will foul the inside of the choke unit/

[karterfred88]

Yes, air is drawn in through the open tube end, down the loop into the cross over back to the choke housing heating the coil and sucked into the carb through a port inside the choke housing.

[bezhawk]

Actually on the older WCFB manifolds there is no "loop" And the choke heat stove is of course closed. The pipe from the choke is open on the end, and sits down into this closed "well". There should be a nipple or "branch" brazed to the heat stove. A rubber line connects to this nipple, and to the airhorn of the carburetor.

[345 DeSoto]

Well, what I have on my intake is a short tube that extends into the exhaust cross over passage. There is no loop, and the end of the tube appears to have some sort of plug in it...it's not carbon, its metal. Is this tube suppose to be plugged or open?

[StudeRich]

Well, what I have on my intake is a short tube that extends into the exhaust cross over passage. There is no loop, and the end of the tube appears to have some sort of plug in it...it's not carbon, its metal. Is this tube suppose to be plugged or open?

So IF this tube is in addition to the one with the Compression Nut to screw onto the Choke Housing, then it is the one Bez mentions that should be OPEN and have a hose to that tube coming out of the side of the Carb. Top.

It is sometimes very hard to explain what should be on these 50+ Year old Cars without seeing them because Studebaker owners are famous for swapping different years of parts around just because they can and they all fit!

Hence Post #3 being about a different Year Manifold.

[345 DeSoto]

These pictures might help explain...

[bezhawk]

The tube in the manifold is the one that should be plugged in the end. The one that screws to the choke is the open one that slides inside the manifold tube.
It's fine just the way it is is how it was designed.

[StudeRich]

If that Exhaust Port tube that goes inside of the Head is plugged as it should be to only let Heat in, not Exhaust, then everything is fine just put it together, it is self explanatory.

You do need the piece of Hose that goes to the Carb. Air Horn that I mentioned in Post #6 however.
The higher Temp hose the better.

[345 DeSoto]

Thanks, again, guys...

[bhapner]

Hmm... I have a carb with an electric choke, The manifold I have had that tube bent and broken. Since I have the electric choke, I removed the tube, tapped and plugged the hole. Is that going to be problem?
bob hapner

[StudeRich]

You are fine Bob, Electric Chokes do not rely on heat.

[bezhawk]

You are fine Bob, Electric Chokes do not rely on heat.

Well.....technically, there is an electric heater in the choke ....hence the name "electric choke"

[345 DeSoto]

How well does the electric choke work on the WCFB's...as opposed to the Stock heat tube system?

[bezhawk]

I would recommend not fixing what ain't broken. The stock set-up worked fine for millions of people for more than a quarter of a century. The WCFB choke system is as good as any carburetor choke. The main reason you would want to change to n electric choke would be if you blocked off the heat passages to keep from vapor locking.