Headwork on a cracked head?

[urquattro]

When I pulled the head on my WX those many years ago I found quite a few
instances of small cracks between the valve seats or from the valve seats to
the spark plug hole.  I guess the Bentley didn't exist at that time ... or
something ... memory is a bit fuzzy.  I remember taking the head to a
rebuilder, who took the thing apart and then told me it was bad and
irreparable.  I got all of the parts back in bags and talked to my brother
in law.  He is not too familiar with Audis, but told me that some Chevrolet
heads had similar symptoms and there was a shop in Oakland, CA that would
grind away the area around the crack, refill and remachine the head.  I had
this done and then reinstalled the head on the car.  The car has run well
until just recently, when I found I had low compression due to a burned
exhaust valve on #2.  When I look at the combustion chamber on the head now
I see no signs of any further cracking ... or any signs that any work was
ever done to the head!  If anyone is interested I can take some digipix ...
unfortunately I did not take any pictures of the head prior to the work for
comparison ...

I'm sorry that I don't have any suggestions to offer on what valves might be
available to allow you to increase the size ...

HTH!
Steve Buchholz
San Jose, CA (USA)
----- Original Message -----
I have looked at porting the head that is going into the 80TQ -83, the
problem is that the head I have here is cracked between the valves. I know
that it should be ignored as long as it is not leaking, but I don't want to
spend the money for a pro port job on a cracked head.

I have heard the term siamesed valveseats here on the list when discussing
larger valves. I guess that it means that the intake and exhaust valve seat
is made from one pice of metall. Has anyone done this? As I see it this will
fix the crack in my head as well.

The above leads me to the valves, where do I get bigger valves, the intake
valve is probably not a problem but where do I get a bigger sodium filled
exhaust valve? What sizes are suitable?