2pc EM p/n

[Phil Payne]

> So on the ur-q's when they crack, most of the owners replace them with
> new single piece manifolds, and make sure the motor mount,
> heatshield, and cooling duct is good, or replace them?

Yes.  It doesn't bother you, but Audi has deleted the one-part manifold
originally fitted to the MB and MC engines, replacing it with the one-part
fitted to the WR and WX.  The difference is in wastegate control - the WR/WX
uses exhaust gas pressure conveyed from an orifice just above the turbo
mount and the MB/MC use (depending on engine level) either unthrottled or
throttled inlet manifold air.  If you're ordering a one-piece for an MC, you
have to order the plugging screw - it's listed on the FPA, though not
clearly.  Otherwise a normal stainless bolt will do.

We see about five ur-quattros a week in the workshop.  Two will usually be
for cracked manifolds.  We've never fitted a two-part.  It doesn't fit
anyway - you have to bash one hell of a dent in the downpipe to clear it,
centimetres from the turbo exit with the´gasflow in a 100,000rpm vortex.

No cooling duct on an ur-quattro - that's a Type 44 issue.

I'm buying another Type 44 next week with a cracked manifold, and I'll
probably put a one-part on even though officially it should have a two-part.
I know the engine mount is gone.

> Do they not have problems after that?  Assuming a good engine mount. I
know Aelred can't say the same - I've got the proof.

Never seen a problem - never had a customer come back.

> In that regard, not that I would want to let the mount go bad and
> transmit those shocks, the cryogenic treatment would help prevent the
> cracking due to relieving stresses and increasing strength.  I "was"
> thinking mostly heat expansion at different rates was causing the
> cracking, not so much shock.  But now I can see where both are
> potential problems.

The quick test is a piece of paper.  Get under the car and see if you can
slip it round on top of the subframe.  If it gets stuck, the engine is on
the subframe.  With practice, you can spot it from the front of the car by
the shape of the sump protrusion - a couple of years ago I spotted about
fifteen in an hour when we brought 240-odd ur-quattros together at
Silverstone - I think all also had cracked manifolds.  I keep meaning to
take a 'good' and 'bad' front picture - if the car is cresting a slight rise
it's incredibly easy to see.

--
  Phil Payne
  http://www.isham-research.com
  +44 7785 302 803
  +49 173 6242039