3B Valve Questions

[Don Muirhead]

Today I've been tearing down a tired 3B I picked up last year from a local 
wrecker.

A couple of things strike me odd and I thought I'd run this by those who 
may have seen this on 3B's before.

All exhaust valves have a severe case of the crackles (cordial cracks) and 
cupping.  All intake valves just show their age and 205k/km...actually 
they're in good shape.

When I see crackles in excess of 70% I think faulty valves or perhaps the 
wrong valves were installed or not seated properly or perhaps the 
combustion pressure was a bit too high.  But to see a contrast to this 
extreme I'm puzzled except that perhaps the exhaust valves might had been 
defective to start with.

Did Audi ever have a recall on exhaust valves for the 3B?  Btw, they are 
the correct valves and nope this head has never been rebuilt.

Any insight?

Thanks,
Don