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I'm a little stuck with something l should have noticed before now but overlooked... the heat riser tube thing from the intake to the choke is now on the wrong side... oof. I guess it'd be more accurate to say that the fitting on the choke (junkyard carb from an 83) is on the wrong side.
It looks like it's just press-fit into the intake, but it's so rusty that I'm about 100%sure it'll break off as soon as l start messing w it. Bending and reflaring it is out of the question for the same reason.
Any solutions? Block it off? Break it, drill it out and replace it? Jeez... l said before that this thing has been fighting me, but this one looks like an unforced error on my part.
Well... ho-lee CRAP!
I flooded it with penetrating oil and worked it around for a bit and... it came out! I was not expecting that.
Muddah, Faddah kindly disregard this lettah..
(anybody remember that song?)
I'll be heading up to the parts store for a (probably universal) replacement. My day just got a lot better.
Hit the hardware store and get copper tubing. It is easier to bend and can be flared to fit the fitting.
Dorman makes a repair kit for the choke heat tube but that will only work if the tube fit the carb to start with.
BTW that tube goes to the EXH manifold not the intake manifold.
Dave ----
So for those of us who've had them break off.. maybe heat the intake, soak, heat, soak, use an easy out and pray..?
I just soaked it in PB Blaster, let it sit, wiggle it w Vice Grips and repeat. I think l was very fortunate that it came out in one piece. Heat might help, even running the engine up to temp to get the manifold hot. I think a reamer, EZ-Out, or drill could cut away the remains of a broken-off tube.
I went to three different parts stores (the only 3 we have in town) and none of them had any idea what l was talking about, go figure. They could find the Dorman universal repair kit, but no one had one in stock and the Dorman kit doesn't do anything l can't do w a hunk of 1/4" brake line... so that's what l got.
I'll (probably) have to pie-cut and shrink the end that goes into the exhaust manifold because the hole measures slightly smaller than 1/4 inch (.223 or something) or maybe just file some OD off it.
I've seen these offered for sale online, but they're always for a 64-65 Mustang i6... anybody tried those? I can't compare the pics to real life because l don't have one to compare... the whole reason behind this escapade.
I did not think anyone would have the Dorman kit as not many cars / trucks used that heat tube for the choke and when was the last car or truck that had a carb rolled off the factory line?
On the 64-65 Mustang parts I cant say if they will or will not work but something to think about.
Back then the six used I am sure was a 170 CID and maybe a 200 CID. Heck I had a 67 Bronco and a Mustang fast back with a small six and I dont remember what the choke working looked like.
I also believe the 170 six had the intake manifold casted as part of the head, it did not bolt on like ours and the 200 might have been the same?
What you are doing is what you got to do. If you have the steel line OK but the copper is easier to deal with.
Dave ----
I drilled the manifold bolt out to 1/4" and the brake line slipped right in (after l cut the flare off)
l suck at bending hard lines, but l was pretty happy with my first edition... until l tested the air cleaner for fit. no Bueno.
More persuasion and it all goes together. Ugly, but marginally effective and no interference from the air cleaner, throttle cable, or anything else that l can see.
One more question on this subject;
The (apparent) other part of this system exits out of the manifold and goes... where? To a vacuum source on the carb? There's a ported vacuum port that looks like a match, but I'm not sure. I shoulda taken pictures, I'm really surprised l didn't, knowing my memory as l do.
This pic is taken from the passenger side fender...
Red is where the tube exits
Yellow and Green are available vacuum sources, one each: manifold and ported.
The sorta clean, silver tube is the heat riser tube l bent up earlier today
The choke is the vacuum source the other side is the clean air side.
I believe that hose nipple is where a hose would go and the other end to the other metal line.
Is that it in the bottom of the picture?
It should go into the bottom of the exh manifold.
So the path of air is thru the air filter to the carb> to that fitting> hose and metal line> bottom of exh manifold> out the top of exh manifold> metal line> carb choke housing to heat it.
Did you put that white cover on the new metal line going to the choke housing?
If not it may loose heat and not open the choke.
Dave ----
The choke is the vacuum source the other side is the clean air side.
I believe that hose nipple is where a hose would go and the other end to the other metal line.
Is that it in the bottom of the picture?
It should go into the bottom of the exh manifold.
So the path of air is thru the air filter to the carb> to that fitting> hose and metal line> bottom of exh manifold> out the top of exh manifold> metal line> carb choke housing to heat it.
Did you put that white cover on the new metal line going to the choke housing?
If not it may loose heat and not open the choke.
Dave ----
At the bottom of the picture above, just to the left of center is the opening of the tube l'm asking about. I think l get the cycle now... l want ported vacuum so it won't be pulling at idle, is that it? The choke will pull heat from the exhaust? I need to find a diagram of what it's actually doing to fully understand it.
l didn't put the heat wrap on, the original fell apart and the stuff at the parts store was too big (and expensive). I'll try to track something down. Now that it's fitted, taking it off to slide a heat wrap on won't be hard.
My understanding is the vacuum on the choke pulls air from the air intake, runs it through the tubing that gets heated by the exhaust and then uses that hot air to heat the choke coil so it opens up. I just went and bought an electric choke personally.
You probably have had a vacuum leak all along. Like the others said, the vacuum for the system is on the round black choke housing, the source is internal to the carb. The fitting where the hard line hooks to the choke housing should suck on your finger with the engine running.
The other end you are talking about hooks right to that larger nipple in the picture below. Top center in the picture, the nipple coming right out below the aircleaner mounting surface. That nipple goes right into the throat of the carb where it can suck clean air from the center of the air filter.
