Actually, Mark, the hushpower II can be
had in 304 or 409 Stainless Steel alloy. 409 are apparently a special grade of
stainless designed for exhaust system – apparently the surface will
oxidize but then stabilize – undoubtedly cheaper alloy to use and
probably last longer than mild steel. Mine is made of the 409 and it too shows
signs of rust, but no signs of serious deterioration.
I missed the angle shape, so I agree,
should last considerably longer. Naturally we are all interested in what you
find out.
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Mark Steitle
Sent: Friday, January 16, 2009
11:20 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Re: DNA
Muffler
That is exactly what I was concerned about too. But if you look
closely, you can see that the bars are made
of 90* angle. That should make them much stronger than
straight bar stock. Not sure what material the cross bars are made
from though. The p/n 1040 is made to weld to a header/collector
and they claim it is good for up to 1000hp.
I have gone ahead and ordered one. I figure it couldn't be
any louder than the Hushpower II whose guts are laying on the hangar
floor in a pile of powder and small pieces. Based on its short
lifespan and the rust-colored debris, I doubt the Hushpower muffler's innards
are made of SS. ;-(
On Fri, Jan 16, 2009 at 10:08 AM, Ed Anderson <eanderson@carolina.rr.com>
wrote:
Appears somewhat similar in concept to the SpinTech muffler
using baffles/ladders to break up the sound wave front. The thing I would
wonder about is whether those ladders which appears to stretch across the
diameter of the tube could withstand the pulse pounding from the rotor.
My experience with the turbo 13B (with no exhaust splitters) would indicate it
might not long withstand that pounding. But, I could be wrong about that.
Guess you're going to have to buy one and let the rest of us
know, Mark.
Ed
From: Rotary motors
in aircraft [mailto:flyrotary@lancaironline.net]
On Behalf Of Mark Steitle
Sent: Friday, January 16, 2009
9:05 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] DNA Muffler
Does anyone
on the list have any real-life rotary experience with the DNA
Gen II muffler (http://www.dnamufflers.com/DNA/main_DNA.html)? It is an
interesting design in that it has no packing material to burn out.
Instead, it utilizes ladder-rungs, which they call "internal sound
diffusers", which resemble a chain of DNA down through the center of
the muffler body, which is made of 304 SS. Their web site claims that the
racers use them with great success. From speaking with a sales rep, they
claim there the rotary crowd uses them too. I'm considering purchasing
one of their FULL THROTTLE COLLECTOR mufflers (P/N 1040), but thought I would
check to see if anyone else has used this style muffler. This
muffler has a 3" inlet/outlet with a 4" body. So it is compact
enough to fit inside my cowl. My exhaust header has a 3" swivel
joint, so it should be a good fit.
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