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Re: Exhaust manifold questions...
Jeffrey J. Goggin wrote:
> Here's another matter I'd like some input on ... I assume that when I
> (finally) get the exhaust manifold off, I'm going to find it cracked and, if
> not, with 86k on the car, I figure it will crack sometime soon.
> I have the Extrude-Honed exhaust manifold from Ben Howell's pre-V8 Ur-Q and
> the cracks in it have been welded up (nice job, too) ... what are the odds
> of it cracking again soon if I use it? At the rate it's going, this isn't a
> job I'll be anxious to do again anytime soon. (P.S.: I bought it for my
> racecar, figuring that if it ever did crack -- okay, when it cracks -- it
> wouldn't be that big of a job to replace. This is clearly *not* the case on
> a street car!)
> Would I be better off using a Dialynx manifold (does it really deliver a
> performance improvement as claimed?) or making a two-piece manifold fit?
> I'd like to keep the costs in check, if at all possible, which means I'd
> really prefer to use Ben's old manifold but I'm willing to spend the money
> for a new one, if necessary...
> Any input will be appreciated.
> _ _
> / | _| o | \ _| o Jeffrey Goggin
> /__| | | / | | __ | | | | / | | email@example.com
> / | |_| \_| | |_/ |_| \_| | http://people.delphi.com/audidudi
Dialynx manifold comes with a flex joint that they recomend to install
behind down pipe or in our case cat. This flex joint works like bellows
on VW golf. It isolates the manifold from movement of the rest of the
exhaust system. They recomend using both their manifold and flexjoint
to eliminate any further manifold problems. When I stopped by there to
see the production of home made short quattros I purchased the flex joint
to use in my car.
I just went through what you are about to do. I did it all because of
blown Turbo. I also stripped an intake manifold bolt but
in addition to that I drilled an opening for an Easyout and went into
aluminum of the manifold itself. Than without knowing it I placed the
Easyout in and broke it. I removed the head with Turbo and downpipe
together. It was easy to disassemble it on the work bench. BTW this is
how we do it during rally repairs exept rally cars are stripped of
accesories and that allows quick removal and refitting. I didn't do any
modifications to my cylinder head. I had it cleaned in hot tank with
alkali solution. I had seats resurfaced and new guides fitted and all
broken studs removed. Valve springs were tested and shimmed and valve
heights were set. My intake manifold was repared to perfection with
heliarc welding by JY Racing in New Milford, CT. I installed rebuilt
watercooled K26 with custom hose for oil supply so I could keep the
original 2 filter oil thermostat. I have no interest in tuning this car
for reason that overall it is still very old technology and there is many
cars out there that are more fun and faster. My conversion to watercooled
turbo was for durability reasons. The historical value of my coupe is
why I still have it. It is also why I am replacing H&R springs with
original ones and yellow Koni struts with Billstein or Boga. I have also
removed all the urethane bushings and aluminum subframe mounts and
replaced with rubber. I am, however envolved in rallying and have another
purpuse built car. If this coupe was my only outlet for automotive
expression I would probably modify it more.
Also I had fresh water pump and timing belt fitted less than a year prior
so I just slipped off the belt and didn't move the pump at all. I placed
Raceware studs. I think because of that I will never be able to remove
this head together with downpipe again. The downpipe will not clear the
firewall with these studs in place. Deffinaly get a right tap and clean
the cylinder head bolt holes. I purchased my tap from Raceware together
with studs. Head gasket kit is a great convenience and is very complete.
Turbo studs and nuts are very expencive. Recently I saw a lockal Audi
garage to remove broken studs placed in with Thred locking compound.
It was not amusing. I know you will not do that.
Good luck. Don't spend money on modifications. You will need it to spend
on your girlfriend to make her forgive you for spending all your free
time on this car and not with her. This job took so much of my time.