2-piece exhaust MF, 10v turbo question

[Alex Kowalski]

OK on to the next issue.  In anticipation of the engine swap I'm going to do
on the '86, and because I enjoy spending money on Audi parts that I might
never use, a few weeks ago I bought a 2-piece exhaust manifold for the 10
valve MC1 turbo from Canada.  The manifold arrived and it's in very nice
shape EXCEPT for a hairline crack...but not where you might expect.  The
crack is at the base of the "Y" where the runners meet at the turbo inlet.
The crack is horizontal, hairline about 1/4" from the base of the Y and
extends back into the manifold outlet about 3/4".  If you go to this page
and scroll down to the picture where the two manifolds are juxtaposed,
imagine a hairline horizontal crack about 1/4" up the base of the "Y."

This puzzled me, because it doesn't seem to fit the usual description of
cracks that develop on these manifolds. Otherwise, it's in very nice shape.
I am aware of Phil Payne's idea that the cracking is precipitated by motor
mount failure, of course I'll be replacing mine on both cars soon.  The
question:  can I have this crack welded?  Any speculation as to why it
appeared there, of all places?  I'd like to use this manifold but I
certainly don't want any bits flying out and being ingested by the
turbocharger...

Cheers,
Alex