onspeed

The AIR tube flange coming off the passenger header (1" 7/8 Kooks) has cracked right at the base. AIR system has been deleted already. Can this be fixed with the header in the car or am I going to have to remove it?

TIA

P.S. What is everyone's thoughts on running 87 octane? I noticed we didn't have one of these yet today.

LoneStarFRC

Depending on the specific location of the crack, yes it should be able to be re-welded. As long as it's accessible for whoever's going to be doing the welding. Chose your welder wisely as some people may claim to be able to weld stainless, but can't and will burn right through the material with too much heat. A well-experienced mig welder should be able to handle it in just a few minutes time. A welder's blanket to protect the surrounding area is a good move too.
Also, if they are going to use electric welding, be sure to disconnect your battery first as a precaution to protect the pcm.

onspeed

Noted.

What if I wanted to remove the AIR fitting entirely? I assume it'll eventually crack again if I just fix the crack...

LoneStarFRC

If properly welded it shouldn't. Iv'e got close to 80 or 90K mikes on my Kooks and no worries, but the skill of the welder is very important.

You'll start kicking code(s) if you just remove stuff.

onspeed

AIR system has already been removed and the codes deleted.

I remember reading something about how a block off plate causes heat to build up and weaken the weld at the base of the fitting, thus causing the crack.

My main concern is whether it's something that could be done with the headers installed. PITA to remove/install them.

LoneStarFRC

Oh, OK. I was not aware you had everything removed already. In that case it will likely make things even easier. Dremel/Sawzall the pipe off, ream/drill the hole to the appropriate size and tap in a small freeze plug. They come in a variety of small sizes, even down to 1/2" maybe 7/16". Weld her up and you're good.

If you can't find the small size freeze plug (aka "cup plug") at your local AP, many automotive machine shops keep them on hand in a variety of sizes.

onspeed

That's a pretty good idea. Well, I'll bring it by an exhaust shop on Monday and if they want some insane amount to cut/weld, or if there's not enough room, I'll just do what you suggest.

baxsom

Thats why I just bought headers that didnt have the AIR system. I read too many times that they crack.

Rex99Coupe

How many miles with air block off plates before they cracked?

onspeed

2,000 or so?

onspeed

Brought it by a shop, they said the header would have to come off in order to do any welding work, which is lots of $$$ in labor of course. Going to just put in a freeze plug as LongStarFRC suggested.

LoneStarFRC

Rats. Have you checked to see if possibly brazing is a possibility? I'm not sure if the temps encountered that close to the exhaust ports would allow for brazing to be viable.

If you do remove the small tube and go for a plug, be sure to not get the hole too large as a tight fit would be really important come time to put the cup plug in. Maybe even consider tapping threads and screwing in a brass screwplug would be the way to go too. Your working with tubing though, so that could be tricky due to the relative thin-ness of the material.

Let us know how you make out.

SoDiezl350

This might seem ghetto, but it is by far the best header sealant I've ever used:

madmatt9471

First off don't freaking cheap out and buy 87 Octane for the Vette -

Now as far as the Air Tube goes just take it to a muffler shop you trust and he should have no problem welding up the stainless steel on the the header while on the Vette!

Thanks,Matt

onspeed

Was joking about the 87 octane since there's a thread literally every day about whether 87 octane can be used or not.

I'm going to take it to a different shop this week to see what they say, before I get my hands dirty. The shop I asked today was a general 'vette shop, not an exhaust specialist.

We'll see what they say. If they agree that it can't be done in the car, I'll either try to cut it off and plug it, or try SoDiezl350's sealant, till I have the time to take the header off and get it fixed properly.

LoneStarFRC

Good plan. It's a pain in the bonzola any way you look at it.

MRNZ06

Same problem here, shop welded on spot, seems ok, car smell anything now!