Header repair

I have the basic Greddy turbo package on my '91, and it's developed
the well-known crack just in front of the turbo flange. At first, I
patched it (then it was quite small) with JB weld and all went well
for a good 30K miles. Now, however, the crack has reappeared and
extends to the bottom of the manifold. I've lost about 2lbs of boost
and tricked my oxygen sensor into making the thing run way too rich.
I first noticed that on my air/fuel ratio guage, but after a while my
blackened rear bumper made the gauge moot.

So....I'm faced with getting a replacement manifold, but first wanted
to ask if there's any possibility of just welding the crack. I
bounced this off my extremely car-smart son (he's currently running an
'04 WRX STI with over 400hp....I thought my worries were over when he
returned from a tour with the Marines in Iraq, but I guess one's kids
will always be a worry). He seems to think there might be a problem
with welding a manifold, but isn't quite sure.

Anybody have any experience in such a fix, or is it wise?

DonB
'91 white

Don Benton wrote:
> I have the basic Greddy turbo package on my '91, and it's developed
> the well-known crack just in front of the turbo flange. At first, I
> patched it (then it was quite small) with JB weld and all went well
> for a good 30K miles. Now, however, the crack has reappeared and
> extends to the bottom of the manifold. I've lost about 2lbs of boost
> and tricked my oxygen sensor into making the thing run way too rich.
> I first noticed that on my air/fuel ratio guage, but after a while my
> blackened rear bumper made the gauge moot.
>
> So....I'm faced with getting a replacement manifold, but first wanted
> to ask if there's any possibility of just welding the crack. I
> bounced this off my extremely car-smart son (he's currently running an
> '04 WRX STI with over 400hp....I thought my worries were over when he
> returned from a tour with the Marines in Iraq, but I guess one's kids
> will always be a worry). He seems to think there might be a problem
> with welding a manifold, but isn't quite sure.
>
> Anybody have any experience in such a fix, or is it wise?
>
> DonB
> '91 white

My turbo miata came with a cracked manifold as an extra part, I don't
remember the brand, but it was known for cracking at the flange.
Research showed that a lot of people who had bought them had them
re-welded and reinforced with satisfaction.

The guy who did my car replaced the manifold with a better one rather
than having it repaired. I sold the cracked turbo manifold and it is now
on a miata in Canada after being welded.

I would feel comfortable with having it repaired as long as I knew that
the welder was really good at his or her trade. Some welders will
probably do no better than the JB-Weld job, but there are some who can
probably make it stronger than new, and if so, for less than the cost of
buying a new manifold.

Pat