Emissions era air injection tube rusted off manifold

[Carmine]

I did do a search on this, and cannot believe I didn't turn up any results. I would think this problem is common as dirt on the emissions era formal Big Blocks.

The passenger side exhaust manifold has a hole at the rear, very near where you would pull the transmission dipstick from. Of course this tubing is relatively thin and by now has probably rusted away on most any of these cars that are not hermetically sealed. Of course when it rusts all the way off, you have a fairly good exhaust leak.

In a perfect world you would simply remove the bolt that attaches this pipe to the manifold, replace it with a solid blank of metal and bolt it back on again. But in the real world, this fairly small bolt snaps off leaving the thread in the manifold.

With a little bit better accessibility, one could probably pound a plug into the hole. But not much room to swing a hammer between the firewall and exhaust manifold. I'm hoping I can find a correctly sized Bolt and create enough of a thread to get it to stay in place within the remains of the tube/ hole in the manifold. Guess I'm just asking if anyone has been here already and has a better idea for a fix?

Photos of the tubes mounting flange and broken bolt attached below.

 

[68HemiRR]

I did do a search on this, and cannot believe I didn't turn up any results. I would think this problem is common as dirt on the emissions era formal Big Blocks.

The passenger side exhaust manifold has a hole at the rear, very near where you would pull the transmission dipstick from. Of course this tubing is relatively thin and by now has probably rusted away on most any of these cars that are not hermetically sealed. Of course when it rusts all the way off, you have a fairly good exhaust leak.

In a perfect world you would simply remove the bolt that attaches this pipe to the manifold, replace it with a solid blank of metal and bolt it back on again. But in the real world, this fairly small bolt snaps off leaving the thread in the manifold.

With a little bit better accessibility, one could probably pound a plug into the hole. But not much room to swing a hammer between the firewall and exhaust manifold. I'm hoping I can find a correctly sized Bolt and create enough of a thread to get it to stay in place within the remains of the tube/ hole in the manifold. Guess I'm just asking if anyone has been here already and has a better idea for a fix?

Photos of the tubes mounting flange and broken bolt attached below.

View attachment 660202

The HP engines didn't have the AIR. They used these plugs.

 

[commando1]

I think this situation is ideal for JB Weld. No?

 

[57fury440]

Maybe, like you said, find a bolt that almost fits and screw it in, only use some JB Weld around it to hold it in and seal it. If the manifold was easy to get off, then I would tap the hole and put in a plug.

 

[Just Carbs]

Brass pipe plug.

 

[Carmine]

I think this situation is ideal for JB Weld. No?

What I read says JB Weld is good up to about 500°. My concern would be the expansion and contraction of a chunk of cast iron that gets that hot. You can watch it at night and it basically shoots fire.

 

[Carmine]

Maybe, like you said, find a bolt that almost fits and screw it in, only use some JB Weld around it to hold it in and seal it. If the manifold was easy to get off, then I would tap the hole and put in a plug.

This is basically the idea I have so far. Luckily a piece of tube came out this morning when the exhaust was cold, so I have a good idea of the diameter now.

 

[Carmine]

Brass pipe plug.

Giving this one consideration as well, one challenge is that it would be very hard to swing a hammer between that exhaust manifold and the firewall. However I was thinking a 2x4 against the firewall and some kind of screwjack to press it in.

 

[Just Carbs]

Giving this one consideration as well, one challenge is that it would be very hard to swing a hammer between that exhaust manifold and the firewall. However I was thinking a 2x4 against the firewall and some kind of screwjack to press it in.

Threaded brass pipe plug.