> 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.
--
Paul Lamar ...No rotor no motor.
If so news to me Tracy had a spin tec; it worked well for him
but he wanted to explore a less exspensive option. I forgot
what he's flying now but it could have been that his less exsp
muffler didn't hold up over the long run .
Clifton
Paul,
What I recall is that the Spin Tech worked well, but it was square which
caused high drag. The Hushpower II is bullet-shaped and therefore much
lower drag. I would be willing to try a Spin Tech if I could fit it
inside the cowl.
Mark
I think it might fit. Do you have the dimensions or can get them.
I can do a 3D. One problem may be it won't handle 300 HP.
Check the inlet pipe size. What size is your down pipe?
Paul Lamar ...No rotor no motor.
Paul,
Sorry, I don't have a Spin Tech muffler to measure. I'm sure I could
fit it inside the cowl, but it would require a new exhaust system as
mine is pointing down and back. My most recent effort included a custom
ball joint with 3" inlet and a 2.5" outlet. I'll look today to see if I
have room for a 180* bend. If so, I could possibly make it fit along
side the exhaust.
Mark
They should give you the dimensions if you contact them.
Paul Lamar ...No rotor no motor.
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