Ceramic Coatings

[james accordino]

NOT a metalurgist, but heat cycles are a cause of
metal fatique.  The stainless exhaust system on my
dorf F-250 literally disintegrated at between 375-425k
miles.  Cracks throughout and then pieces of the metal
falling out.  It looked just like if you break a hard
boiled egg and a few of the shell pieces come out.  No
rust or corrosion issues.

Jim Accordino

--- Brady Moffatt <bradym at sympatico.ca> wrote:
> Hi Doyt,
>
> There was an element of skepticism regarding header
> wrap earlier on this
> thread. I share it, though not through personal
> experience. I have a friend
> who used header wrap on his 240Z headers. They
> disintegrated in just a
> couple of years. Granted the headers may have been
> cheap (I don't know), but
> my Z's headers are over 10 years old and are still
> in good shape. Mine had
> no header wrap. I've heard something about the wrap
> keeping the heat in so
> well that the metal gets way hotter than it's
> designed for, and therefore it
> weakens and fails quickly.
>
> This may be a load of bunk, but it makes sense to
> me. Any metallurgists out
> there?
>
> Cheers,
> Brady Moffatt
> Montreal, Quebec, Canada
> 86 4kq with 299,000km
> 86 4kq parts car
> 72 Datsun 240Z with 180,000 miles
> 92 VW Golf with 192,000km FOR SALE
> in early stages of quattrosis accumulatus
>
> ----- Original Message -----
> From: "Doyt W. Echelberger" <Doyt at NWOnline.Net>
>
>
> > I just rebuilt an air cooled engine and put a
> layer of wrap on the exhaust
> > headers before putting it back in the car. What
> kind of problems can I
> > expect if I continue to run it with the wrap in
> place?
> >
> > I used the wrap because I wanted to get the
> radiant header heat away from
> > the cooling fins and the case, so the oil wouldn't
> get so hot.
> >
> > I can take off the wrap pretty easily if there is
> a big risk of some kind.
> > I imagine it is a risk of warping, or melting, or
> burning away of metal.
> > They are stainless steel headers.
> >
> > Doyt Echelberger
> > 76 VW Westfalia Bus with 2 liter engine
> >
> >
> >  >>>>>>>>>>>>>>>>>>>>>>>>>>>..
> > At 10:14 AM 12/3/2002 -0500, you wrote:
> > >Hi Jim/All,
> > >.........snip............. All that heat trapped
> in the metal would
> > >probably cause problems similar to header wrap.
> > >
> > >Cheers,
> > >Brady Moffatt
>
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system
> (http://www.grisoft.com).
> Version: 6.0.423 / Virus Database: 238 - Release
> Date: 25/11/02
>


__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com