I came across a thread on Audizine (linked here: http://www.audizine.com/forum/showth...pdate-12-03-11 ) regarding engine failure of a catastrophic nature for B6/B7 4.2 liter V8 engines.
They complain about a number of issues, such as broken timing chains (looks like a major architectural change from the RS6 4.2), and issues like broken rods, scorched cylinder walls, and other assorted issues.
Are RS6 engines susceptible to these same maladies, or would the unique handbuilt nature of the engines (and perhaps different design and architecture) play a role in keeping us immune from the issues that are being seen on the B6/B7 4.2 V8s?
Is the RS6 motor known for any sort of catastrophic failure mode different from the S4's 4.2 engines?