I use these: http://tinyurl.com/exhnut

Standard exhaust manifold nut for BMW and MBZ.  They work really well on the
Vanagon headers due to the larger seating surface, but still use a 12mm
wrench size.

Cheers,

Jeff

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
David Beierl
Sent: Monday, May 07, 2012 11:54 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: 2.1 Exhaust. P. 26.9 Bentley: "5 Diaphragm Springs" ?

At 01:15 PM 5/7/2012, neil n wrote:
>Image:
>https://lh6.googleusercontent.com/-0tqzGn0WwFE/T6gB740u5eI/AAAAAAAAFuM/
>0vRYhIVlLd0/s576/cadmium%2520plated%2520%253F.jpg

Always hard to tell from photos on monitors, but that looks like a
copper-plated nut to me.  Cadmium (nasty toxic stuff) tends to a
light-yellow color.  Here's Febi's take on the subject:
http://www.germansupply.com/home/customer/product.php?productid=16355

I bought a box of 100 for not a whole lot more than that from my local truly
friendly imported auto specialist a few years back.  They weren't as fancy
as the Febi ones, though.  Nice heavy copper, thicker than I would have
called "plating."

Solid brass has been recently put forward here as the aviation answer.

The concave washer p/n is 025 251 200, dunno if still available from VW.
Out in the Real World it's called a Belleville Washer (see
http://en.wikipedia.org/wiki/Belleville_washer )* and you can get them from
lots of places including Belleville themselves (in England).  Might have to
do some calculating to figure out what spec you need that would flatten out
with normal torque on an M8x1.25 nut though, or whether VW wanted one that
would actually not completely flatten and would give a little flexibility in
the joint.  Getting hold of an original would help a lot.

*These are on my list as one of the cleverest inventions in the universe...

Yours,
David