[urq] 2-Piece Manifold

[Brandon Rogers]

My local machinist here in Denver who is very familiar with Aude heads
recommends time-serts.  He did several for me on a WX head. That was
probalby 8-9 yrs ago.  Wish I could give you a progress report but I only
had the motor for about a year before doing the 3B conversion - then I think
it lived on in another car here in Denver for several years. As far as I
know they were never an issue.

Brandon 
'84 urq 20Vt

 
 


-----Original Message-----
From: urq-bounces at audifans.com [mailto:urq-bounces at audifans.com] On Behalf
Of racingiron at comcast.net
Sent: Wednesday, January 19, 2011 6:44 PM
To: urq Audifans
Subject: [urq] 2-Piece Manifold





I haven't driven my car much in the past year. Anyone who's heard it run
lately can identify the distinct sound of exhaust gases successfully
escaping their manifoldly confines. It has a two-piece manifold, but the
leak is obviously coming from its vicinity. I pulled it last weekend to find
the source... 



I found four obvious cracks: two on the underside, and two more in the
dividers at the turbo end. I also found evidence of significant exhaust
escaping around the #1 port and its predominantly AWOL gasket, and maybe a
hint around #2 and #3 ports. We think at least one of the nuts on #1 wasn't
as tight as it should've been. Due to the volume of the leak, I suspect the
#1 port is the main source. Here are some pictures of the manifold in
question: 

http://home.comcast.net/~racingiron/ExMan/manifold1.jpg 
http://home.comcast.net/~racingiron/ExMan/manifold3.jpg 
http://home.comcast.net/~racingiron/ExMan/manifold4.jpg 
http://home.comcast.net/~racingiron/ExMan/turbo1.jpg 
http://home.comcast.net/~racingiron/ExMan/turbo2.jpg 

Removal (with head in situ) wasn't fun, but better than I expected. Only two
studs refused to be divorced from their nuts, preferring to separate from
the head instead. Unfortunately, the lower #2 stud apparently harbored
strong attraction for the head as well, retaining bits of it in about half
the threads. My German cohort (with not insignificant MB surgical experience
in the Fatherland) thinks I might be able to get away with a simple retap
(or rather, chasing with 3 progressively aggressive taps), while I'm leaning
towards a helicoil-type repair. The #2 location seems to lend itself to
drill application with the airbox and turbo conveniently out of the way. 

So, my questions: 
- Fix or replace the manifold? The cracks in the collector seem unlikely to
be easily repaired. How tough is it to find a good 2-piece replacement these
days? 
- Advice on the lower #2 stud threads in the head? Tap? Helicoil? Time-sert?

- Oh yeah, we snapped one of the brass barbs on the CIS intake dome. Is
there an reasonable fix for this, or should I just cap that hole and put a
tee on the second one? 

TIA, 
Eric R. 
'86 urq 
'92 urS 
'93 urS 
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