Date:         Fri, 16 Jan 2004 08:01:11 EST
Reply-To:     THX0001@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         George Goff <THX0001@AOL.COM>
Subject:      Re: Exhausting Exaust
Content-Type: text/plain; charset="US-ASCII"

In a message dated 1/15/04 6:01:06 AM, RAlanen@AOL.COM writes:

<< . . . No way you can go there with a drill to
drill out the broken studs  & bolts. . . .

. . . If the nuts and bolts break off the best way is drop the engine. . . .

. . . Then drill out the broken bolts & studs, fit helicoil thread repair
inserts to all eight  locations then use stainless steel bolts of the proper
length at ALL  locations.

. . . Clean up the exhaust  port gasket surface before putting the engine
back.  Good clean surface  here is IMPORTANT to having the gaskets seal well.
ALSO, use Loctite  Ultra Copper High Temp Silicon Sealant on both sides of the
gaskets. . . .

. . . To make all this expensive work worthwhile and to  not have to visit
this
scene again sometime in the future think about fitting a  stainless steel
exhaust
system.  See my _STEBRO/Vanagon Stainless Steel  Exhaust System. . .
Cheers,

Frank  Condelli >>

While I agree with some points here, I disagree with others.

It is possible to drill out a broken stud and install a HeliCoil with the
engine in place.  To be done with certainty, the work requires a close quarters
right angle drill motor, aircraft drills (or shortened jobber's drills) and an
accurately made drill plate to keep the drill perpendicular.  Dropping the
engine certainly makes the work much easier, but for one hole it is hard to
justify the hassle.

I prefer key locking inserts to HeliCoils because they will never back out
with the fastener as has known to happen with HeliCoils.  Also, the inserts use
standard sized taps instead of the dedicated taps required by HeliCoils.

One dodge for someone stuck in the middle of the night with no access to a
proper repair insert is to tap the hole to a 3/8-16 thread.  A stripped 8mm
tapping is already very near the tap drill diameter (5/16") of a 3/8-16 thread
anyway.  If the 3/8-16 tapping gets bitched, there is still enough material
remaining to drill the hole for a HeliCoil or some other type of repair insert.

I also use stainless steel fasteners to secure the header pipes, but I prefer
to use studs instead of capscrews (aka, bolts).  I adjust the head pipes so
that they are an easy fit over the studs instead of fighting and prying the
pipes into place only to strip a thread by running in a cocked capscrew.  The
first van I bought had the material of the head beside one of the studs broken
out.  I was puzzled about how that could happen until the first time I renewed
an exhaust system.  Then, I imagined the wrestling match that must have
occurred until the stud broke free of its hole.

The use of Loctite Ultra is dubious at best.  There are various exhaust
sealants, Loctite Ultra is not one of them.  A properly prepared gasketed flange
joint does not require it and, like smearing RTV on an O-ring, it might cause
more harm then good.

I tried aftermarket exhaust parts more than once before I returned to using
the real deal, i.e., VW-OE-bought-from-the-dealer.  My experience with
aftermarket exhaust parts echoed the sage advice I received many years ago from Gordi
of 4ever4 in New Hampshire whenever I asked if he sold stainless exhaust
parts.  He said that an OE system is a proven quantity which lasts for 100K, so,
what more could you ask for?

While I have never used the Stebro system, what I have seen of it does not
impress me.  From the first time I realized that the things of my world did not
drop out of the sky, but were made by man, I have been taught to use the
fewest connections possible in any fabrication be it electrical, piping or
mechanical in nature.  It is the hallmark of a craftsman to do such work.  Yet, the
photo's posted of the Stebro muffler show what appears to be a clumsy assemblage
of patch pieces stuck together with sloppy welds.  Someone far wittier than
myself has called it a "Spam can" muffler.

Also, the mounting brackets (?) attached to the Stebro appear to have been
designed more as an expediency to allow a wide latitude in the fit of the
muffler than to hold it fast.

Perhaps, above all else, it is made of Type 409 SS which, although it is
filling the racks of every muffler shop in the Free World, is only recommended for
use in mildly corrosive conditions.  The material of choice for corrosion
resistance at elevated temperatures is Type 321 SS and for the cost of the Stebro
system nothing less should be used.

George