Smog tubes for headers?

[Webslinger60]

Anybody ever weld Smog Air tubes to a set of headers.

I have an 80’s carbureted vehicle that has stock manifolds with the air injection fittings.I’ve tried to run with the smog pump disconnected, but it WILL NOT pass my state emissions check without it.

I’d like to increase the exhaust performance with a set of headers but nobody makes headers with the smog fittings for my application.
I know the mini-manifold-tube things are available separately. Has anyone ever attached these to a set of headers that didn’t have it? How would you do it? Drill, tap, & mount fittings in each runner & thread the tubes on? Or drill holes & weld the smog-tube-thing directly into the runners? And if you did it, did the welds last for awhile, or did they break?

[burly]

Are you sure that your car must have an emissions inspection?

It depends on the state and the area but you may not be required to pass an emissions check if the vehicle is a certain age. I know in Virginia, emissions are only required in certain areas of the state, on top of which, if your vehicle is over 15 years old, it is deemed a "classic" and does not require an emissions inspection.

[twokie]

has to be 30 years old in cali. heh.

[Webslinger60]

I live in NJ, where the DMV & EPA make no emissions exception for classic cars or anything built after 1971. In fact they even LOWERED the minimum HC ppm count by one tier level. Now my 1980 car which was designed to run at 500ppm, must now get better than 300. (81+ cars need to get 150 or less). I can neutralize all the early-design power-robbing, systems like EGR, OSAC, etc. But the Smog pump (and Cat convt) are a must. I used to pull the belt on the pump & still run
at 475ppm. With the pump running I can get 297.

[MagicRat]

Originally Posted by Webslinger60

Anybody ever weld Smog Air tubes to a set of headers.

I have an 80’s carbureted vehicle that has stock manifolds with the air injection fittings.I’ve tried to run with the smog pump disconnected, but it WILL NOT pass my state emissions check without it.

I’d like to increase the exhaust performance with a set of headers but nobody makes headers with the smog fittings for my application.
I know the mini-manifold-tube things are available separately. Has anyone ever attached these to a set of headers that didn’t have it? How would you do it? Drill, tap, & mount fittings in each runner & thread the tubes on? Or drill holes & weld the smog-tube-thing directly into the runners? And if you did it, did the welds last for awhile, or did they break?

Drill holes in the header tubes right beside the cyl head flange. Weld on a suitable female threaded fitting. You could also braze a brass fitting on. Then screw in the tubes of the somg-tube-thing.
Edelbrock makes a wide variety of headers with these fittinga already installed. If they do not have one for your application, at least take a look at one of their headers to see how it's done.

[Webslinger60]

That’s exactly what I plan to do in general, but specifically, I’d like to hear from somebody who’s actually done it, because this kind of welding job must be done correctly. No company makes smog headers for my particular application. And no local store stocks those Edelbrock smog headers, so I cant examine a set up close.
Hedman co makes generic, tubes that you weld directly into the runners, but I prefer the screw-in GM type, just in case they ever break & need replacing. I can get replacement tubes from part stores or from GM. The tubes spaced for a SB Chevy will fit my headers, but what do I use for the screw-in bases? Do I use steel & weld, or brass & braze? The air injection makes the exhaust flame much hotter than normal, so the bond must not ever break from heat stress, or crack after time.

[MagicRat]

Brazing will not be affected by the heat, but welding is stronger. MIG welding is recommended given the thin steel. I suggest take it to a welding/fabricating shop and let them do it. If you are not experienced at welding, you could ruin an expensive set of headers by learning how to do it.