RE: Cracked EM...

["Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>]

Interesting note!  I'd heard that Chevy had similar problems in this regard
... but simply saw the manifold in half?  Do they just assume that the two
parts will seal up well enough that there is no need to put something over
the break to seal it?  Do you know if the manifold is a "log" style (i.e.
one common collector) or individual?  The thing about the Audi turbo
manifold is that it has three individual separate runners, so when you saw
the thing in half behind the turbo mounting flange you need to connect two
somewhat independent exhaust paths together ... exactly what Audi did with
their 2-piece design.  The only thing is that they use short tubes to
connect the runners in each half, and a big bellows coupling to cover the
whole thing.  

Steve Buchholz
San Jose, CA (USA)

> -----Original Message-----
> 
> The point of the cracking manifolds, their being replaced
> with 2-piece manifolds, and the potential difficulty/cost
> od obtaining replacements reminds me: Due to lots
> of occurences of LT1s (as well as L99s, the 4.3l version
> of the Caprice version of the Camaro version of the
> Corvette engine :) in Caprices having their right-hand
> side EM crack, GM has (besides a manifold that is
> split at the engine end for the last 1.5 years of production)
> a TSB that says to saw the engine-facing side of the
> identical-to-stock replacement EM in half on the older
> cars, thus reducing heat-expansion stress. 
> Maybe something like this is possible on the
> 1-piece Audi manifolds? (such that it's still one piece,
> but the 2 "halves" are joined only at the downpipe end)
> 
> 
> -gbr
> 
>