81 Exhaust manifold question

[Feltman]

My passenger side exhaust manifold air tube to manifold broke off about a 1/2 above the manifold. I have a couple of questions.

First, I have removed all smog equipment and th air tubes are plugged.

1. Can I cut the tube flush with the manifold and have a patch welded over the hole.

2. Can I cut the tube flush and install a heilcoil and plug?

3. Will 1980 exhaust manifolds work without modifiications.

Thanks in advance for your help

 

[bill81vette]

I don't see why any of the other SBC manifold wouldn't work.but I would save the 81's as they are unique as that's the only year they made them like that...

JMO

 

[Rawj]

Pardon my ignorance, but what is so special about the '81 exhaust manifold other than hard to find in the off market?

 

[Yoda]

The 81 exhaust manifolds are tubular stainless steel, very light weight.

NOTE: these were designed and used on the 1980 CA Emissions Corvettes (LG4 engine)

Bud

 

[Rawj]

Thanks Bud....,
Not much stainless left on mine.

Merry Christmas

 

[Feltman]

Can they be welded??

 

[Dave L.]

yes.

 

[Tom Bryant]

Here are a few pics of a pair of '81s I bought from Chris Mc Donald (69MYWAY) that I'm using on my '69 truck project. They are stainless like Bud said. It is a rough stainless of a lower grade alloy not sutable for polishing so that is way they look like they do, not just a coating. On these the rusty looking stuff was actually just burned on crap. When I cleaned them off the stainless is untouched. The one picture is with the heat shield removed.

The next is showing that the AIR tubes are welded through the exhaust tubing and extend into the port path about 1/2 inch. If you want to leave that portion of the AIR tube in place you could tap the hole and install a plug without removing them from the car, depending on access.

The last picture is the one I have partially cleaned and on the engine for a test fit. I have yet to weld up the holes and install new studs. I'll finish removing the tube that extends into the exhaust tube and have a welding shop close up the hole.

Tom

 

[Dave L.]

I've got a set of those manifolds I bought off ebay last year. I'm getting them back from buddys shop next week after he welded the holes shut and ground down the rough interior edges. I'm sending them out to Jetcoat to have them finished. I'll post a couple pictures when I get them back. I'll keep the ones I have on the car for spares or if I ever want to return to stock condition.

 

[Peer81]

If you want to weld them shut, i would go for a set of 82 manifolds. No difference there if you weld them but they have a 2.5" exit and 81s only have 2".

Groeten Peter.