Exh Man

[Audinamx <Audinamx@aol.com>]

My tuppence on the EM thread ...

I did have to deal with the broken studs on the '83 when I bought it.  
Fortunately for me it was due to the fact that the EM was warped ... 
not cracked.  In those days reports I'd heard were that it was most 
likely to warp ... sounds like the newer cars like to crack ... guess 
I'll find out which I'm up against on the Avant.  

The advice I got was to have the EM resurfaced and the problem will 
not recur ... that certainly has been my experience.  The other thing 
I was told that makes sense to me is that if you know that you have 
broken studs then it is more likely that you have a warped manifold 
rather than a cracked one.  Except for the #1 stud which decided to 
back itself out, I haven't had a problem in the 10 years hence; with 
the car being my daily driver for the first few of the 10.  My theory is 
that the casting has some stress in it, which gets worked out through 
the annealing cycles it endures through use.  Once you have the EM 
resurfaced it shouldn't recur.  I do agree with Scott though ... if you're 
gonna do the RS2 then you should go ahead and get the 2-piece ... 
they have been found in wrecking yards you know ...

On the coating thread ... the coating should be done on the inside 
surface of the manifold ... this means that the exhaust gas is insulated 
from the metal and less heat is transferred.  You would not expect the 
coated parts to heat up even after the engine is shut down ... If you 
coated the outside you would still have heat transferred to the EM ... 
and the insulating coating on the outside would allow the manifold to 
get HOTTER than it would without the coating. 

Steve Buchholz
San Jose, CA (USA)