X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao107.cox.net ([68.230.241.39] verified) by logan.com (CommuniGate Pro SMTP 5.3.8) with ESMTP id 4411598 for flyrotary@lancaironline.net; Thu, 29 Jul 2010 19:09:00 -0400 Received-SPF: softfail receiver=logan.com; client-ip=68.230.241.39; envelope-from=glasair2@me.com Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao107.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100729230826.DXHU14902.fed1rmmtao107.cox.net@fed1rmimpo01.cox.net> for ; Thu, 29 Jul 2010 19:08:26 -0400 Received: from [192.168.2.201] ([70.177.24.126]) by fed1rmimpo01.cox.net with bizsmtp id nz8R1e00B2jEC4N03z8RFi; Thu, 29 Jul 2010 19:08:25 -0400 X-VR-Score: -100.00 X-Authority-Analysis: v=1.1 cv=atnVLXso/ZAvPKALjQcfOkxYrpEEKc6RlNgW2Y2qy5c= c=1 sm=1 a=7mRKtoZ49N4A:10 a=f32ykCDtWUuHg+z19x9HKQ==:17 a=Ia-xEzejAAAA:8 a=oBdLjE-hAAAA:8 a=3oc9M9_CAAAA:8 a=HHGDD-5mAAAA:8 a=7g1VtSJxAAAA:8 a=ZDcs8UurGfyaznRKICIA:9 a=SJejp-5q5NNkPKmr9IoA:7 a=6GmO_BCznLF-acuaZxOCkr6KqocA:4 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=184Z8XVtRNwA:10 a=EzXvWhQp4_cA:10 a=U8Ie8EnqySEA:10 a=i1zE5R4R5dEA:10 a=HbSAiMLhp3bS_gvR:21 a=J6emfbJvRge3Mepk:21 a=ve6UCi6UK0M-BH_bLr0A:9 a=xRtGGMQtVL2fqNFh1B0A:7 a=715epplXmHin4C7p4i7qACzks_8A:4 a=f32ykCDtWUuHg+z19x9HKQ==:117 X-CM-Score: 0.00 From: Steve Thomas Mime-Version: 1.0 (Apple Message framework v1081) Content-Type: multipart/alternative; boundary=Apple-Mail-15--657488825 Subject: Re: [FlyRotary] Re: Noise Measurements Date: Thu, 29 Jul 2010 16:08:25 -0700 In-Reply-To: To: Rotary motors in aircraft References: Message-Id: X-Mailer: Apple Mail (2.1081) --Apple-Mail-15--657488825 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=iso-8859-1 Yes, it is easily repacked - specifically designed to do so. I'll keep = you-all posted on the longevity issue. Best Regards, Steve Thomas _______________________________________________________ On Jul 29, 2010, at 4:52 PM, Bobby J. Hughes wrote: > Steve, > =20 > That "sounds" great. I hope the packing holds up. Can it be repacked = easily? The Austin bunch is going through Hushpower II resonators pretty = fast. I'm on my second one and it's starting to sound different. I think = Dennis H is down to just a can without any internals. But his RV7 is = still very quiet. I don't have any issues when keying the mic with my = Lightspeed. I only have one flight with my new Zulu and it works great. = Better than my 20XL that's gone missing. > =20 > Bobby Hughes > RV10 Super Renesis > =20 >=20 > From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Steve Thomas > Sent: Thursday, July 29, 2010 4:31 PM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: Noise Measurements >=20 > Well, I just made a guess and measured it at 100 ft. I'll measure = cockpit noise later, when I've got some flight time in. Here is my = story: >=20 > I have a Glasair Super II RG with a Mistral 2 rotor engine. I've had = it in the air once, and landed immediately as there was an oil temp = problem that turned out to be a measurement problem. However, what I = did find that was particularly annoying was the noise. My LightSpeed = Zulu handled the noise fine until I keyed the mic. Man, what a blast of = noise! I could barely hear the tower. =20 >=20 > The muffler that I was using was a 2 1/2 inlet/outlet and 3 1/2" = diameter Burns Stainless device that I purchased many moons ago. It was = made up with stainless scrubble innards. So, I decided to replace it = with another Burns Stainless muffler, but a 2 1/2" inlet/outlet, 6 1/4" = diameter, dual stage muffler. See: =20 >=20 > http://www.burnsstainless.com/sm-300-625-17-2s.aspx >=20 > Although this one has a 3" inlet/outlet, they made one for me with the = 2 1/2". What a difference!!!! Here are the measurements I took from = 100 feet, off the wing tip and about 30=BA aft. They also put in a = stainless cloth material instead of the stainless scrubble. They claim = that it works great for the rotary. =20 >=20 > idle: 57-60 DB > 1500 RPM: 78 DB > 2000 RPM: 87DB >=20 > By RPM, I mean prop at 2.85-1 reduction ratio. I was fearful that = going any higher would put my prop too close to the ground as the nose = gear compressed down with power. I suppose you math-types can = extrapolate different distances. =20 >=20 > I'll be hitting the air tomorrow. While I had one short flight = already, this will be much longer, hopefully and I can see what the = plane will do. >=20 > The only real disadvantage of the muffler is that it hangs underneath = the belly and looks ugly. But it, so far, works terrific. I hope the = drag penalty is not too great. =20 >=20 > BTW, the rest of my exhaust consists of 2" headers into a collector = with a 2 1/2" outlet made with .065 321 SS. =20 >=20 > Best Regards, >=20 > Steve Thomas > _______________________________________________________ >=20 >=20 >=20 >=20 >=20 > On Jul 29, 2010, at 12:52 PM, wrjjrs@aol.com wrote: >=20 >> Steve, >> =20 >> Typically the measurement for cars and motorcycles is at 50 feet away = at 90 degrees to the directin of the exhaust flow. Any in-cabin = measurements wouldn't need orientation, just put the pick up about where = your head is. >> =20 >> Bill Jepson >>=20 >>=20 >>=20 >> -----Original Message----- >> From: Steve Thomas >> To: Rotary motors in aircraft >> Sent: Thu, Jul 29, 2010 9:31 am >> Subject: [FlyRotary] Noise Measurements >>=20 >> I want to take some noise measurements today with a new muffler I = just=20 >> installed. What is a reasonable distance from the aircraft to be = taking these=20 >> measurements? Right next to the airplane seems to be somewhat = unreasonable, and=20 >> distance makes a big difference. =20 >>=20 >> Best Regards, >>=20 >> Steve Thomas >> _______________________________________________________ >>=20 >>=20 >>=20 >>=20 >>=20 >>=20 >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html >=20 --Apple-Mail-15--657488825 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1 Yes, = it is easily repacked - specifically designed to do so.  I'll keep = you-all posted on the longevity issue.

Best Regards,

Steve = Thomas




=

On Jul 29, 2010, at 4:52 PM, Bobby J. Hughes = wrote:

Steve,
 
That "sounds" great. I hope = the packing holds up. Can it be=20 repacked easily? The Austin bunch is going through Hushpower II = resonators=20 pretty fast. I'm on my second one and it's starting to sound different. = I think=20 Dennis H is down to just a can without any internals. But his RV7 = is still=20 very quiet. I don't have any issues when keying the = mic with my=20 Lightspeed.  I only have one flight with my new Zulu and it works = great.=20 Better than my 20XL that's gone missing.
 
Bobby = Hughes
RV10 Super Renesis =
 

=
From: Rotary motors in aircraft=20= [mailto:flyrotary@lancaironline.net] On Behalf Of Steve=20 Thomas
Sent: Thursday, July 29, 2010 4:31 PM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Re: Noise=20 Measurements

Well, I just made a guess and measured it at 100 ft. =  I'll=20 measure cockpit noise later, when I've got some flight time in. =  Here is my=20 story:

I have a Glasair Super II RG with a Mistral 2 rotor engine. =  I've had=20 it in the air once, and landed immediately as there was an oil temp = problem that=20 turned out to be a measurement problem.  However, what I did find = that was=20 particularly annoying was the noise.  My LightSpeed Zulu handled = the noise=20 fine until I keyed the mic.  Man, what a blast of noise!  I = could=20 barely hear the tower.  

The muffler that I was using was a 2 1/2 inlet/outlet and 3 1/2" = diameter=20 Burns Stainless device that I purchased many moons ago.  It was = made up=20 with stainless scrubble innards.  So, I decided to replace it with = another=20 Burns Stainless muffler, but a 2 1/2" inlet/outlet, 6 1/4" diameter, = dual stage=20 muffler.   See:  


Although this one has a 3" inlet/outlet, they made one for me with = the 2=20 1/2".  What a difference!!!!  Here are the measurements I took = from=20 100 feet, off the wing tip and about 30=BA aft.  They also put in a = stainless=20 cloth material instead of the stainless scrubble.  They claim that = it works=20 great for the rotary.   

idle:  57-60 DB
1500 RPM:  78 DB
2000 RPM:  87DB

By RPM, I mean prop at 2.85-1 reduction ratio.  I was fearful = that=20 going any higher would put my prop too close to the ground as the nose = gear=20 compressed down  with power.  I suppose you math-types can = extrapolate=20 different distances.  

I'll be hitting the air tomorrow.  While I had one short = flight=20 already, this will be much longer, hopefully and I can see what the = plane will=20 do.

The only real disadvantage of the muffler is that it hangs = underneath the=20 belly and looks ugly.  But it, so far, works terrific.  I hope = the=20 drag penalty is not too great.  

BTW, the rest of my exhaust consists of 2" headers into a collector = with a=20 2 1/2" outlet made with .065 321 SS.  

Best Regards,

Steve Thomas
_________________________________________= ______________




=

On Jul 29, 2010, at 12:52 PM, wrjjrs@aol.com wrote:

=
Steve,
 
Typically the measurement for cars and motorcycles is at 50 feet = away at=20 90 degrees to the directin of the exhaust flow. Any in-cabin = measurements=20 wouldn't need orientation, just put the pick up about where your head=20= is.
 
Bill Jepson





= --Apple-Mail-15--657488825--