Another Bone Headed...

So I am re-wrapping the fiberglass around the header (Merge 4:1) and the
oil lines that are suspended between two.

I got the wrap locally, but they had none of the stainless straps. The
straps in question are thin, impervious to heat as seen for four years
of use, and 'snippable' (can cut the leetle guys with a wire cutter.)

Local FLAPS people sell the wrap and never heard of the proper ties. So
they suggested the stainless doobies used to tie off universal joint
boots. noooooo, they don't tie down far enough and man are they
impossible to cut or what? Had to use a dremel.

Dunno. I'm just a-whining. I love living in the sticks except when I
need some kinda urban thing.

Peace,
John Boy

On Thu, 10 Sep 2009 03:47:38 +0200, John Stafford >
wrote:

> So I am re-wrapping the fiberglass around the header (Merge 4:1) and the
> oil lines that are suspended between two.
>
> I got the wrap locally, but they had none of the stainless straps. The
> straps in question are thin, impervious to heat as seen for four years
> of use, and 'snippable' (can cut the leetle guys with a wire cutter.)
>
> Local FLAPS people sell the wrap and never heard of the proper ties. So
> they suggested the stainless doobies used to tie off universal joint
> boots. noooooo, they don't tie down far enough and man are they
> impossible to cut or what? Had to use a dremel.
>
> Dunno. I'm just a-whining. I love living in the sticks except when I
> need some kinda urban thing.
>
> Peace,
> John Boy


You should be able to use plastic cable ties on the heat insulator if it
is of any value.
Remember that header wrap can crack headers in very warm climate.

J.

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Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

In article >,
"P.J.Berg" > wrote:

> Remember that header wrap can crack headers in very warm climate.

Really? How?

On Thu, 10 Sep 2009 18:18:46 +0200, John Stafford >
wrote:

> In article >,
> "P.J.Berg" > wrote:
>
>> Remember that header wrap can crack headers in very warm climate.
>
> Really? How?

Not entirely sure about physics behind it, I know for sure Rallye Raid'ers
in vintage cars, like in the Peking to Paris are strongly advised against
it.
It could relate to cast iron manifolds only?
It is a debated subject, but those who had failures had heat wrap, the
others not..

J.



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In article >,
"P.J.Berg" > wrote:

> On Thu, 10 Sep 2009 18:18:46 +0200, John Stafford >
> wrote:
>
> > In article >,
> > "P.J.Berg" > wrote:
> >
> >> Remember that header wrap can crack headers in very warm climate.
> >
> > Really? How?
>
> Not entirely sure about physics behind it, I know for sure Rallye Raid'ers
> in vintage cars, like in the Peking to Paris are strongly advised against
> it.
> It could relate to cast iron manifolds only?
> It is a debated subject, but those who had failures had heat wrap, the
> others not..

I think it really might relate to cast iron because it is brittle and
especially because it is unyielding. When my header was installed, it
yielded fairly easily to bending it to fit properly (and tightly). I
have dual quiet packs on the header, and they are supported by strong
springs to the chassis. Springs let it move a bit when necessary.

I've studied a fair amount of information regarding exhaust pipe heat.
It is interesting that the temperature of the exhaust gas falls at a
huge rate per inch. The first three or four inches are so hot that the
header radiates strong infrared. Then the temp drops until at the exit
of the muffler, it's just warm.

The infrared radiation can head all the components near that part of the
header and no amount of air cooling or wind can help any more than you
can blow the beam of a flashlight aside - because infrared is radiation.

Wrapping helps a lot in that regard.

With wraps, the temperature remains high so that the gasses flow faster
- there is less cooling due to denser (cooler) air in the pipe.

The Bad News is the heat is very high were the wrapping stops - if you
were to have the header blow at your pants leg, you could be badly
burned.

The ultimate bad news is that my full-flow oil lines passed too close to
the end of the wrapping. A line melted, spewing Mobil-1 straight onto
the unwrapped part and EXPLODED in a ball of flame that the cars behind
me will probably never forget. (I saw it immediately and hit the kill
switch. Kill switches - some thing I learned from building motorcycles.
A very good idea.)

But the explosion and its aftermath is a story for another day.

On Sep 10, 5:55*pm, John Stafford > wrote:
> In article >,
>
>
>
> *"P.J.Berg" > wrote:
> > On Thu, 10 Sep 2009 18:18:46 +0200, John Stafford > *
> > wrote:
>
> > > In article >,
> > > *"P.J.Berg" > wrote:
>
> > >> Remember that header wrap can crack headers in very warm climate.
>
> > > Really? How?
>
> > Not entirely sure about physics behind it, I know for sure Rallye Raid'ers *
> > in vintage cars, like in the Peking to Paris are strongly advised against *
> > it.
> > It could relate to cast iron manifolds only?
> > It is a debated subject, but those who had failures had heat wrap, the *
> > others not..
>
> I think it really might relate to cast iron because it is brittle and
> especially because it is unyielding. When my header was installed, it
> yielded fairly easily to bending it to fit properly (and tightly). I
> have dual quiet packs on the header, and they are supported by strong
> springs to the chassis. Springs let it move a bit when necessary.
>
> I've studied a fair amount of information regarding exhaust pipe heat.
> It is interesting that the temperature of the exhaust gas falls at a
> huge rate per inch. The first three or four inches are so hot that the
> header radiates strong infrared. Then the temp drops until at the exit
> of the muffler, it's just warm.
>
> The infrared radiation can head all the components near that part of the *
> header and no amount of air cooling or wind can help any more than you
> can blow the beam of a flashlight aside - because infrared is radiation.
>
> Wrapping helps a lot in that regard.
>
> With wraps, the temperature remains high so that the gasses flow faster
> - there is less cooling due to denser (cooler) air in the pipe.
>
> The Bad News is the heat is very high were the wrapping stops - if you
> were to have the header blow at your pants leg, you could be badly
> burned.
>
> The ultimate bad news is that my full-flow oil lines passed too close to
> the end of the wrapping. A line melted, spewing Mobil-1 straight onto
> the unwrapped part and EXPLODED in a ball of flame that the cars behind
> me will probably never forget. (I saw it immediately and hit the kill
> switch. Kill switches - some thing I learned from building motorcycles.
> A very good idea.)
>
> But the explosion and its aftermath is a story for another day.

Just wrapped the pipes on my motorcycle after I tore up the chrome
heat-shields riding in the mountains. Was itching like crazy last
night after doing the pipe-wrap thing. I guess the fiberglass
particles got to me. Anyway, end result for those of you (everyone
except Chris and PJ and Jan and Kid) who aren't "lucky" enough to be
my friend on facebook:
http://photos-e.ak.fbcdn.net/hphotos..._2075489_n.jpg
Also just put baffles into the pipes for the first time ever. Have
got about 12K miles on the bike since buying it last October. Made it
to the front page (highlights) of killboy.com two weeks in a row.
WOOT!
Latest killboy shot... won't be there long:
http://4.bp.blogspot.com/_LxZ4Mi3rR3...h/img_4354.jpg