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Drivers side manifold question

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Old Sep 10, 2017 | 01:28 PM
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Default Drivers side manifold question

So I discovered this morning that I think a bolt fell out. I have a loud "backfire" inside the engine bay. Leave the car run in the garage and pull the throttle under the hood and I see a lovely blue flame coming from the manifold. Turns out there is a threaded hole where a bolt should be that the flame is coming out. It is right dead on to hit the steering box so driving it will not happen now.

Attached is a picture of the threaded spot. Any ideas what goes there or what size bolt I need to put in to close that? Fire in the engine bay seems unsafe 😂
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Old Sep 10, 2017 | 01:50 PM
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Hi t,
That hole is where one tube of the Air Injection Reactor 'tree' attached to the exhaust manifolds.
There should be 4 threaded openings like the one in your picture in each manifold.
The others are probably plugged and you can plug this one too.
Regards,
Alan


Last edited by Alan 71; Sep 10, 2017 at 01:53 PM.
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Old Sep 10, 2017 | 01:56 PM
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Default Plug

Originally Posted by Alan 71
Hi t,
That hole is where one tube of the Air Injection Reactor 'tree' attached to the exhaust manifolds.
There should be 4 threaded openings like the one in your picture in each manifold.
The others are probably plugged and you can plug this one too.
Regards,
Alan

Alan,

That's what I was hoping to hear. Do you happen to know what size, threading of bolt I should use to do that?

Thank you!!
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Old Sep 10, 2017 | 02:09 PM
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I'm impressed you were able to get those out. I was trying this morning with mine. They are frozen in place.

I believe those are the remnants of the A.I.R/Smog injection tubes:
https://www.corvettemods.com/C2-C3-C...QaAuqmEALw_wcB

The PO may have removed the tubes, and plugged the hole. I have a set of these ready to go in, if I can ever get the old ones out:

http://www.rickscamaros.com/camaro-e...1967-1981.html

You may be able to find a plug that fits at Home Depot. Try this thread for the size:

https://www.corvetteforum.com/forums...plug-size.html
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Old Sep 10, 2017 | 04:46 PM
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Make sure to use socket head set screws from a well-equipped hardware store (Junk stores like Ace won't have them). Do NOT use 1/4" pipe plugs, the tpi (threads per inch) is wrong and the thread dia tapers. Yours prob came out because Bubba put pipe plugs in there.
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Old Sep 10, 2017 | 06:18 PM
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Originally Posted by 68notray
Make sure to use socket head set screws from a well-equipped hardware store (Junk stores like Ace won't have them). Do NOT use 1/4" pipe plugs, the tpi (threads per inch) is wrong and the thread dia tapers. Yours prob came out because Bubba put pipe plugs in there.



Those holes are NOT pipe thread........
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