X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from rv-out-0506.google.com ([209.85.198.236] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3430444 for flyrotary@lancaironline.net; Fri, 16 Jan 2009 19:52:11 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.198.236; envelope-from=msteitle@gmail.com Received: by rv-out-0506.google.com with SMTP id f6so2160637rvb.7 for ; Fri, 16 Jan 2009 16:51:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=WkbxDQYEIVu0xVHQJ2J40uhgSErr2Hc1xKb0r+hYUCA=; b=qgZ0lqhgg69sooQp4uwhaQNg1vi6pbeXX2UH016jvrSKzoys7R4vurnA6lop/E5P9T Tf5wo+ZCf6MnSxvPOauRVmVmBlzo01bzjCmar8uU0fyYXwsdGzmL2S0k1MX7ov3acySR gLkpLJywml4rf5eaiReIZIJ3lXXk7jbRkr8Mg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=pMhl78+aWFWd3BSMn58QuIZnvF/cN4PmR3qDdbsMyiY4YdmAKJ1dDn3JYb0TVFXGdA xPk6mfEVSd5/+3hX+IZ8f1TIeuViqIXVaOM7ovNq8HtJsWc3d4HzCaRvtif/SUVj9xSH 4JVyCK3LGvpBgmNYoO+noBIWbNXYN8d/73GKo= MIME-Version: 1.0 Received: by 10.141.193.9 with SMTP id v9mr1426198rvp.120.1232153495738; Fri, 16 Jan 2009 16:51:35 -0800 (PST) In-Reply-To: References: Date: Fri, 16 Jan 2009 18:51:05 -0600 Message-ID: <5cf132c0901161651y4f846543m44fd39ee8e7d057c@mail.gmail.com> Subject: Re: [FlyRotary] Re: DNA Muffler From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000e0cd259be6c1a530460a317e4 --000e0cd259be6c1a530460a317e4 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit George, With the edges of each cross bar pointed downstream of the exhaust flow, I don't see a problem with the heat attacking them. Also, if one were to somehow break loose, I don't see how it could manage to block the exit, maybe partially, but not totally. The engine should still run at reduced power if that were to happen. I would like to special order one made of 321ss. Also, if you look at the DNA web site, you'll see that they make a Gen 1 and a Gen II. The Gen II is much stronger as the cross bars protrude through the can and are welded from the outside. The Gen I bars are spot welded to the can. The Gen II is also more than twice the price of the Gen I. Mark S. On Fri, Jan 16, 2009 at 4:10 PM, George Lendich wrote: > Mark, > The heat and pulses attack/ affect the weakest part of any internal part, a > thin edge is the weakest part. You will notice that I don't expose and edges > to the sound wave or hot gases. > George ( down under) > > Ed, > > 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. ;-( > > Mark > > On Fri, Jan 16, 2009 at 10:08 AM, Ed Anderson 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 >> >> >> >> Ed Anderson >> >> Rv-6A N494BW Rotary Powered >> >> Matthews, NC >> >> eanderson@carolina.rr.com >> >> http://www.andersonee.com >> >> http://members.cox.net/rogersda/rotary/configs.htm#N494BW >> >> http://www.dmack.net/mazda/index.html >> ------------------------------ >> >> *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. >> >> >> >> >> Mark S. >> >> >> __________ Information from ESET NOD32 Antivirus, version of virus >> signature database 3267 (20080714) __________ >> >> The message was checked by ESET NOD32 Antivirus. >> >> http://www.eset.com >> > > --000e0cd259be6c1a530460a317e4 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable George,

With the edges of each cross bar pointed downstream of the = exhaust flow, I don't see a problem with the heat attacking them. = Also, if one were to somehow break loose, I don't see how it could man= age to block the exit, maybe partially, but not totally.  The engine s= hould still run at reduced power if that were to happen.  I would like= to special order one made of 321ss.  Also, if you look at the DNA web= site, you'll see that they make a Gen 1 and a Gen II.  The Gen II= is much stronger as the cross bars protrude through the can and are welded= from the outside.  The Gen I bars are spot welded to the can.  T= he Gen II is also more than twice the price of the Gen I.  

Mark S.

On Fri, Jan 16, 2009 at 4:10 = PM, George Lendich <lendich@optusnet.com.au> wrote:
Mark,
The heat and pulses attack/ affect the= weakest part=20 of any internal part, a thin edge is the weakest part. You will notice= that=20 I don't expose and edges to the sound wave or hot gases.
George ( down under)
Ed,
 
That is exactly what I was concerned about too.  But if you loo= k=20 closely, you can see that the bars are made=20 of 90* angle.  That should make them much stronger th= an=20 straight bar stock.  Not sure what material the cross bars are = made=20 from though.  The p/n 1040 is made to weld to a header/collecto= r=20 and they claim it is good for up to 1000hp.    
 
I have gone ahead and ordered one.  I figure it couldn't be= =20 any louder than the Hushpower II whose guts are laying on the h= angar=20 floor in a pile of powder and small pieces.  Based on its short= =20 lifespan and the rust-colored debris, I doubt the Hushpower muffler's= innards=20 are made of SS.  ;-(
 
Mark

On Fri, Jan 16, 2009 at 10:08 AM, Ed Anderson = <eanderson@carolina.rr.com>=20 wrote:

Appears somewhat=20 similar in concept to the SpinTech muffler using baffles/ladders to bre= ak up=20 the sound wave front.  The thing I would wonder about is whether t= hose=20 ladders which appears to stretch across the diameter of the tube could= =20 withstand the pulse pounding from the rotor.  My experience with t= he=20 turbo 13B (with no exhaust splitters) would indicate it might not long= =20 withstand that pounding.  But, I could be wrong about=20 that.

 

Guess you're going=20 to have to buy one and let the rest of us know, Mark.

 

Ed

 

From:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Friday, January 16, 2009 9:05= =20 AM


To: Rotary motors in=20 aircraft
Subject:= =20 [FlyRotary] DNA Muffler

 

Does=20 anyone on the list have any real-life rotary experience=20 with the DNA Gen II muffler (http://www.dnamufflers.com/DNA/main_D= NA.html)?=   It is an=20 interesting design in that it has no packing material to burn out. = ;=20 Instead, it utilizes ladder-rungs, which they call "internal sound= =20 diffusers", which resemble a chain of DNA down through the ce= nter of=20 the muffler body, which is made of 304 SS.  Their web site claims = that=20 the racers use them with great success.  From speaking with a sale= s=20 rep, they claim there the rotary crowd uses them too.  I'm con= sidering=20 purchasing one of their FULL THROTTLE COLLECTOR mufflers (P/N 1040), bu= t=20 thought I would check to see if anyone else has used this style=20 muffler.  This muffler has a 3" inlet/outlet with a 4" b= ody.  So=20 it is compact enough to fit inside my cowl.  My exhaust heade= r has=20 a 3" swivel joint, so it should be a good fit. =20

 

Mark=20 S.



__________ Informat= ion from=20 ESET NOD32 Antivirus, version of virus signature database 3267 (2008071= 4)=20 __________

The message was checked by ESET NOD32 Antivirus.
<= br>http://www.eset.com


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