A6 4.2L - pros and cons?

[Louis-Alain Richard]

I've heard that story in the past. BMW Formula 1 engines in the turbo era
(same period as the famous Group B) were 1,5 liter 4-bangers. To accept the
stress of 1000 hp, BMW used to take the blocks out of staff cars because
they had some "heat cycling", increasing the resistance of the blocks. In
metallurgy, this process of heat-cycling can help bond the molecules
together, and favors "grain growth". I guess it was an empirical process, as
often metallurgy is.

Louis-Alain 

-----Message d'origine-----

Tony... It wasn't just the sport quattro that received the alum.  
Block... Euro only urq's and 200's were fitted with aluminum blocks  
for homoglaten purposes then during service periods were then removed  
and placed in their Motorsports cars.