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.

You could do a spin tec type muffler or maybe use rock wool or
steel wool instulation type packing.

Clifton

That stuff goes away immediately :) The best plan is put nothing
in the muffler. Parts inside the muffler glow white hot.
You can stand behind this airplane and look down the exhaust
pipe and into the muffler when it is running. Even metal parts
are melted and spit out if they are too thin.

My 182 O-470 will (and has) spit parts out of the muffler eventually.
These are high continuous HP engines not at all related to
car engines.

Paul Lamar ...No rotor no motor.

All the tangential I have made have been .065 321.  I can buy sheet
and roll the canister.   I can't remember where I bought the 2" o.d.
tubing, maybe Burns Stainless.
I have not made one in a couple of years.  Jerry


Go to the spin tec it has been installed on rotaries it is some what costly
thought on the plus side people have made their own version at great cost savings .

Clifton

I think Tracy destroyed one of those too. Auto mufflers are just not up
to it. Perhaps one could copy the Spin Tech using thicker material.