Work finished, Refrigerator & Muffler Fix & Replace

[Pete Masterson]

I had to get the BB muffler -- not cheap! but it wasn't practical for
me to have left my coach at CCW. (If I had it to do over, I might
have dropped the coach off at CCW, then come back for it in 2 or 3
weeks...)

I'm not sure what you're trying to accomplish with the insulation,
wrapping, etc. As installed, there's an inch or so space around the
muffler as it runs up the back corner to the roof. This allows air
flow to carry away the heat through the perforated "grill" at the
roof. It seems like a reasonable design to me. I'd be concerned that
the insulation would cause the internal muffler parts to get
excessively hot.

I understand the desire to paint the muffler to control corrosion --
but isn't the major problem the corrosive effect of the diesel
exhaust on the inside? When my old muffler was pulled out, it was (as
you say) an empty tube. All the internal baffles had vanished. In my
case, the muffler body (tube) was not eroded through except for a
beginning of a hole at the bottom -- probably due to rain water
accumulation.

Indeed, I suspect the major culprit is rain water entering the
muffler from the exhaust port at the top. I attempted to get a true
90 degree stack-end that would tend to keep rain water from entering
the muffler. The (presumably OEM) stack-end was very slightly turned,
but was still mostly open to falling rain. (The replacement that CCW
installed is better, but still will allow wind-driven rain to enter
the muffler, if the wind is blowing the right way.) I plan to put a
bucket or other cover over the exhaust-stack end during storage to
keep the rain water out.

I note that the newest BBs have a 90 degree bend stack-end that has a
foot or so of horizontal pipe, thereby eliminating nearly all chance
of significant rain water collection.

The biggest challenge was finding components in the large diameter
used. Almost all generally available heavy duty diesel exhaust
components max out at 5" diameter.

Pete Masterson
'95 Blue Bird Wanderlodge WBDA 42
aeonix1@...
On the road near Scranton, PA



On Sep 29, 2008, at 1:03 AM, Kurt Horvath wrote:

> <snip>

> The next major task is replacing the muffler. While installing the
> Lil-Stanker powered tank vents I stopped to look at the exhaust
> stack and reached down to give it a little shake and the chromes
> elbow is only held on by the mounting clamp. It's hollow inside, the
> baffels are gone it's just a tube. I have one ordered, they are hard
> to get. Cummins has a 45 to 60 day back order on the
> Donaldson/Nelson/Fleetgaurd muffler part # 86610M. Found one from
> Fleetpride, under $250 delivered to the farm. BB wanted $900 +
>
> I would like to insulate the muffler and or the muffler tunnel. I
> don't really have a heat issue . But since I'm there doing it anyway
> might as well improve it if practical. There is only about 1"
> clearance on each side, the tunnel measures 13" X 13.5 on my coach
> and the muffler is 11.10 in diameter so you can see there isn't much
> clearance to do much of anything. I am considering Thermo Tec exhaust
> insulating wrap. It is rated at 2000 degrees continuos use and 3000
> degrees intermittent use. It comes in 6" wide rolls and shouldn't be
> too hard to install, it's only 1/16th of an inch thick so clearance
> isn't a problem. Paint the pipe with some sort of high temp
> paint/coating to slow down corrosion. I've read that the first few
> runs will cause some smoke/smell but once it's "cured" that will
> stop. Paint the muffler, wrap it, clamp it, paint the wrap to seal it
> from the elements and install on coach, Sounds easy, TOO EASY!
> Somebody with some experience with this needs to chime in here.
>
> Another idea is a smaller diameter muffle with a heat blank from ATP,
> Firwin or Kolb. The Fleetgaurde muffler # 82132M would do nicely. It
> has almost the same flow rate within 100 CFM and it's 9" in diameter,
> that would increase the clearance from the tunnel walls to the
> muffler by 100%. 2" VS 1" The downside is 5" diameter opening VS the
> 6" for the original equipment muffler and pipes. May be a better
> option, but more expensive.
>
> If you get this far through this post I still have 20+ CD's of
> the `95 - `96 PT 42 and `97 PT 43 Diagrams & Blueprints available. If
> you want one send e-mail to kguns@...
>
> Kurt Horvath
> 95 pt 42 wlwb
> 10AC
>
>