X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao103.cox.net ([68.230.241.43] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3877365 for flyrotary@lancaironline.net; Wed, 07 Oct 2009 00:14:19 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.43; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao103.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20091007041343.OAJL11920.fed1rmmtao103.cox.net@fed1rmimpo03.cox.net> for ; Wed, 7 Oct 2009 00:13:43 -0400 Received: from wills ([68.105.87.66]) by fed1rmimpo03.cox.net with bizsmtp id pgDg1c00P1RstZw04gDiw2; Wed, 07 Oct 2009 00:13:43 -0400 X-VR-Score: -250.00 X-Authority-Analysis: v=1.0 c=1 a=2vCnn3GDONkA:10 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=09EMvVImAAAA:8 a=8I59ToNzAAAA:8 a=40f3stCzsaUuBsCJ7Y8A:9 a=KX_CYVC_ps6TlLuGeZIA:7 a=P2M0DCpwgE5YC6yRcVvc9masV_oA:4 a=EzXvWhQp4_cA:10 a=3oAoAkLHBMwvsKz7:21 a=2nuLZuF2RN9yqkJc:21 a=SSmOFEACAAAA:8 a=Hl1Gy0H5AAAA:8 a=kviXuzpPAAAA:8 a=ifiXETK6XUmrLnDZ35QA:9 a=eju7G5TArsKvpDXQDpgA:7 a=XEFL2tgKaf_ZMLRqCLckXkZBChAA:4 a=q4lmfNo8auMA:10 a=4vB-4DCPJfMA:10 X-CM-Score: 0.00 Message-ID: <6D8DDC68D4E84930AAEE1ED643F494E3@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Absorbtion muffler [FlyRotary] Re: engine runup video Date: Tue, 6 Oct 2009 21:13:41 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00AA_01CA46C9.E0FB0B00" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_00AA_01CA46C9.E0FB0B00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed, I assume all of your attempts were built along the lines of a typical = glasspak or "Swiss muffler" with packing either wrapped or stuffed = around some sort of perf tube? The type of muffler I'm considering is the one I mentioned having seen = over the weekend. The reasons I think it might work and live behind the = rotary are: 1) Lots of internal volume. The muffler I saw was at least 8 feet long. 2) The perforated tube down the center ran the full length of the = muffler providing lots of perforations to dissipate the exhaust energy. 3) The muffler introduces fresh air into the muffler to cool the = exhaust. I have no idea if it will really work and I'm not rushing into anything. = But I went out to Miramar and watched the airplane depart on sunday. It = was virtually silent. Mike ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Tuesday, October 06, 2009 3:29 AM Subject: [FlyRotary] Absorbtion muffler [FlyRotary] Re: engine runup = video Good luck, Mike, on the absorption muffler with a rotary. I have = tried a number of different approaches including mufflers with ceramic = packing that can withstand 2000F+. The heat is no problem, the problem = is the exhaust shock wave pulverizes the ceramic/fiberglass/stainless = steel/etc into small pieces in a relative short time. Its true they = were good in suppressing sound while they lasted, but two weeks - 1 = month was about the limit. =20 I still dream of doing a remake of a muffler design I came up with = which had 3" 1/8" stainless steel discs (about 4-5) in a 36" tube. The = disc were slotted and "blades" bent until the disc looked a bit like a = fan. The blades were bent at an approx 45 deg angle. If you looked = down the tube with the disc in it all you saw was solid metal - however = the blades provide room for exhaust gas to flow around them. The theory = was the shock wave would see basically a solid disc and reflect = some/most of its energy back and forth between discs, whereas the gas = could more or less freely flow around and through the blades. =20 The concept worked well in that my hangar neighbors were all remarking = how quite the engine sounded and I could still get a static rpm of = 6000.=20 =20 The problem was I am not a welder and while I had the disc clamped = with Jam nuts to a SS thread rod through their center - it was not = sufficient to keep the exhaust from loosening the nuts and causing the = discs to spin like a turbine wheel. IF I could have welded the tips of = the blades to the tube then it may have been viable. But, not a welder = and got tire of messing with exhaust so I hung two Hushpower mufflers = and went flying. =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Mike Wills Sent: Tuesday, October 06, 2009 12:58 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: engine runup video =20 George, =20 Thanks. Read through it yesterday. Nothing too earth shattering here. = What the article really didnt discuss and what I think is the major = problem we face in aircraft which is less of a problem in a car is the = need to get sufficient muffler volume. Finding space for a muffler that = actually has sufficient volume to do any good on an airplane is = problematic. =20 Havent yet seen the muffler that relies on "reflective" (aka passive = cancellation) that really works. Tried a variety of them on various cars = over the years, and of course the homebrewed "spiral flow" muffler on my = airplane currently. Still waiting for someone to come up with one that = actually works and will fit on my airplane. =20 Meanwhile I am intrigued by the absorptive design which I posted here = the other day. Its the only thing I've seen that actually provides = plenty of volume, appears to be capable of both muffling and lasting, = and wont look too terrible. I'm thinking about trying to throw together = something cheap and easy to try out before committing a bunch of time = and effort. =20 Mike =20 =20 ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Sunday, October 04, 2009 11:38 PM Subject: [FlyRotary] Re: engine runup video =20 Mike, The address is right, but it didn't work when I tried it also. What I did was use up to Miscellaneous on the address and clicked on = exhaust etc on the LHS of the screen - OK. George ( down under) ----- Original Message -----=20 From: Mike Wills=20 To: Rotary motors in aircraft=20 Sent: Monday, October 05, 2009 11:45 AM Subject: [FlyRotary] Re: engine runup video =20 That link didnt work for me George. =20 Mike ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Sunday, October 04, 2009 3:45 PM Subject: [FlyRotary] Re: engine runup video =20 Mike, Here's a good site for general info on mufflers, mine and Bill = Jepson design is around deflection. www.nsxprime.com/FAQ/Miscellaneous/exhausttheory.html George ( down under) ----- Original Message -----=20 From: Mike Wills=20 To: Rotary motors in aircraft=20 Sent: Monday, October 05, 2009 2:34 AM Subject: [FlyRotary] engine runup video =20 For anyone who hasnt had that first engine run and is looking = for some motivation. A buddy visited the hangar a few weeks ago and shot = some video of an engine runup. He posted it to his website and you can = find it here: =20 http://www.stinsonvoyager.com/images/MikeWills13bEngineRun.wmv =20 This was shot right after I re-installed my original muffler = after the aborted DNA muffler test. Noticeable in the video is the big = staging bog. I had this tuned out about 15 minutes after he shot the = video. =20 Mike Wills RV-4 N144MW ------=_NextPart_000_00AA_01CA46C9.E0FB0B00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ed,
 
 I assume all of your attempts = were built=20 along the lines of a typical glasspak or "Swiss muffler" with packing = either=20 wrapped or stuffed around some sort of perf tube?
 
 The type of muffler I'm = considering is the=20 one I mentioned having seen over the weekend. The reasons I think it = might work=20 and live behind the rotary are:
1) Lots of internal volume. The muffler = I saw was=20 at least 8 feet long.
2) The perforated tube down the center = ran the full=20 length of the muffler providing lots of perforations to dissipate the = exhaust=20 energy.
3) The muffler introduces fresh air = into the=20 muffler to cool the exhaust.
 
I have no idea if it will really work = and I'm not=20 rushing into anything. But I went out to Miramar and watched the = airplane depart=20 on sunday. It was virtually silent.
 
Mike
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Tuesday, October 06, 2009 = 3:29=20 AM
Subject: [FlyRotary] Absorbtion = muffler=20 [FlyRotary] Re: engine runup video

Good luck, = Mike, on=20 the absorption muffler with a rotary.  I have tried a number of = different=20 approaches including mufflers with ceramic packing that can withstand=20 2000F+.  The heat is no problem, the problem is the exhaust shock = wave=20 pulverizes the ceramic/fiberglass/stainless steel/etc into small = pieces in a=20 relative short time.  Its true they were good in suppressing = sound while=20 they lasted, but two weeks =96 1 month was about the=20 limit.

 

I still = dream of=20 doing a remake of a muffler design I came up with which had 3=94 = 1/8=94 stainless=20 steel discs (about 4-5) in a 36=94 tube.  The disc were slotted = and=20 =93blades=94 bent until the disc looked a bit like a fan.  The = blades were=20 bent at an approx 45 deg angle.  If you looked down the tube with = the=20 disc in it all you saw was solid metal =96 however the blades provide = room for=20 exhaust gas to flow around them.  The theory was the shock wave = would see=20 basically a solid disc and reflect some/most of its energy back and = forth=20 between discs,  whereas the gas could more or less freely flow = around and=20 through the blades.

 

The concept = worked=20 well in that my hangar neighbors were all remarking how quite the = engine=20 sounded and I could still get a  static rpm of 6000.=20

 

The problem = was I am=20 not a welder and while I had the disc clamped with Jam nuts to a SS = thread rod=20 through their center =96 it was not sufficient to keep the exhaust = from=20 loosening the nuts and causing the discs to spin like a turbine = wheel. =20 IF I could have welded the tips of the blades to the tube then it may = have=20 been viable.  But, not a welder and got tire of messing with = exhaust so I=20 hung two Hushpower mufflers and went = flying.

 

Ed

 

Ed=20 Anderson

Rv-6A = N494BW Rotary=20 Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Mike Wills
Sent: Tuesday, October 06, 2009 = 12:58=20 AM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: engine = runup=20 video

 

George,

 

Thanks. Read through it = yesterday.=20 Nothing too earth shattering here. What the article really didnt = discuss and=20 what I think is the major problem we face in aircraft which is = less of a=20 problem in a car is the need to get sufficient muffler volume. Finding = space=20 for a muffler that actually has sufficient volume to do any = good on an=20 airplane is problematic.

 

Havent yet seen the = muffler that=20 relies on "reflective" (aka passive cancellation) that really works. = Tried a=20 variety of them on various cars over the years, and of course the = homebrewed=20 "spiral flow" muffler on my airplane currently. Still waiting for = someone to=20 come up with one that actually works and will fit on my=20 airplane.

 

Meanwhile I am intrigued = by the=20 absorptive design which I posted here the other day. Its the only = thing I've=20 seen that actually provides plenty of volume, appears to be capable of = both=20 muffling and lasting, and wont look too terrible. I'm thinking about = trying to=20 throw together something cheap and easy to try out before committing a = bunch=20 of time and effort.

 

Mike

 

 

----- Original Message = -----=20

From: George=20 Lendich

To: Rotary motors in = aircraft=20

Sent: Sunday,=20 October 04, 2009 11:38 PM

Subject:=20 [FlyRotary] Re: engine runup = video

 

Mike,

The address is right, = but it=20 didn't work when I tried it also.

What I did was use up = to=20 Miscellaneous on the address and clicked on exhaust etc on the LHS = of the=20 screen - OK.

George ( down=20 under)

----- Original = Message -----=20

From: Mike = Wills=20

To: Rotary motors in = aircraft=20

Sent:=20 Monday, October 05, 2009 11:45 = AM

Subject:=20 [FlyRotary] Re: engine runup = video

 

That link didnt work = for me=20 George.

 

Mike

----- Original = Message -----=20

From: George=20 Lendich

To: Rotary motors in = aircraft=20

Sent:=20 Sunday, October 04, 2009 3:45 = PM

Subject:=20 [FlyRotary] Re: engine runup = video

 

Mike,

Here's a good site = for=20 general info on mufflers, mine and Bill Jepson design is around=20 deflection.

www= .nsxprime.com/FAQ/Miscellaneous/exhausttheory.html=

George ( down=20 under)

----- Original = Message=20 -----

From:=20 Mike=20 Wills

Sent:=20 Monday, October 05, 2009 2:34 = AM

Subject:=20 [FlyRotary] engine runup = video

 

For anyone who = hasnt had=20 that first engine run and is looking for some motivation. A = buddy=20 visited the hangar a few weeks ago and shot some video of an = engine=20 runup. He posted it to his website and you can find it=20 here:

 

h= ttp://www.stinsonvoyager.com/images/MikeWills13bEngineRun.wmv<= /FONT>

 

This was shot = right after=20 I re-installed my original muffler after the aborted DNA = muffler test.=20 Noticeable in the video is the big staging bog. I had this = tuned out=20 about 15 minutes after he shot the=20 video.

 

Mike=20 Wills

RV-4=20 = N144MW

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