o.k. so the hush power muffler is toasting up?

         best,

         George W

       George,

       "Melting" is more like it. After my initial 20 minute flight
   with the
       new HP2 muffler, there was "cake frosting" dripping from the
exhaust
       pipe onto the hangar floor. The 304ss baffle was already
   beginning to
       scale.

       Mark S.

       Mark,
       Scaling isn't that bad a thing. I'm not surprised that your glass
       packing melted. That is to be expected at 1600 F Fine scale on the
       exterior of the muffler wouldn't be uncommon. Is the muffler
   becoming
       misshaped? Is the interior screening melting? I'd like to know
   as I'm
       trying to get all the stuff together for my 20B.
       Bill Jepson


   Bill,
   The airplane is currently down for some electrical mods at this time.
   So, I haven't flown again with the HP2 since the first short flight a
   few weeks ago.  The strange thing is that I didn't notice the melting
of
   the fiberglass until I had shut it down.  It could have already been in
   the process of melting with the fiberglass being blown out the exhaust
   as I flew.  I noticed the goo on the hangar floor after it had been
   parked for 15-20 minutes.  It is amazing that it was still hot enough
to
   continue melting the glass long after shutdown.

   No, the baffle inside the muffler hasn't melted, but it sure looked
like
   it had been through the fires of hell.  We'll see how it holds up.

   My recommendation is to either place the muffler 3-4 feet back from the
   exhaust ports, or build a muffler from inconel or thick 321ss.  Another
   option would be to turbo-charge and forget the muffler.

   I'll report back after I fly again.

   Mark

   Is the Hush Power muffler inside the cowl Mark?

   You have room in there for a huge tangential muffler with
   a JB Wagner thick wall 304 SS Jerry Hey cool tube running down the
   center.

   You may need to add a patch to the outer or inner skin where the
exhaust
   directly impinges on it.

   Paul Lamar



Paul,
I was hoping to locate a piece of inconel tube/pipe or at least 321SS
pipe.  I'm getting tired of building mufflers only to have them
self-destruct in a few hours.  From what I can tell, the Wagner tubes
are holding up.  I hadn't considered using a larger diameter "handrail"
to fabricate a tangential muffler.  I'll check into that.

Mark

P.S.  My tig welder is broken.  ;-(


Too bad. That is bad news. I am sure Jerry will weld something up
for you.

Some heavy duty sheet metal shops can roll up 304 SS into a large tube or
perhaps
two 180 degree sections of  large tube. Same goes for Inconel sheet.

0.065" 304 SS would probably work but .090" would work for sure. I don't
thing Wagner has hand rail in eight or ten  inch in diameter.

Paul Lamar ...No rotor no motor.

Paul,

I've been watching this thread about the mufflers and all these engines are
non turbocharged.  How much heat does the turbo take out of the exhaust?
Does the turbo reduce noise as much as the muffler?

Steve Brazil

A lot of heat and it is almost as quiet as most mufflers.

Paul Lamar ...No rotor no motor.

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