According to the latest MT article pitting the RS6 vs. E55 (which the Rs6 wins by the way!), their tech article says it has 4 valves/cylinder. ???
<a href="http://www.motortrend.com/roadtests/sedan/112_0309_axes/index5.html">MT article</a>

From Audi UK's website: "<i>V8 spark-ignition engine, five-valve technology, biturbo, two light-alloy cylinder heads both with double overhead camshafts (DOHC), inlet camshaft adjustment, three inlet valves, two sodium-cooled exhaust valves.</i>"<ul><li><a href="http://www.audi.co.uk/newcars/specs.jsp?section=/models/a6/rs6saloon&amp;modcode=4B40EZ++00">http://www.audi.co.uk/newcars/specs.jsp?section=/models/a6/rs6saloon&amp;modcode=4B40EZ++00</a</li></ul>

I know Audi bought Cosworth but apparently a different department does the stuff for Ford or something. I heard a few things but I don't remember. Anyone know the story on this?

Ford gets the engine supply company for racing.
Audi gets the meat and potatoes of Cosworth by purchasing the engineering/technology part of Cosworth from Vickers in 1998.
Both outfits are quite remarkable in the business world.
www.cosworth.com is Ford.
Audi is cosworth-technology.co.uk