X-Virus-Scanned: clean according to Sophos on Logan.com From: "William Jepson" Received: from mail-vk0-f44.google.com ([209.85.213.44] verified) by logan.com (CommuniGate Pro SMTP 6.1.12) with ESMTPS id 9048848 for flyrotary@lancaironline.net; Wed, 19 Oct 2016 14:41:28 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.213.44; envelope-from=wrjjrs@gmail.com Received: by mail-vk0-f44.google.com with SMTP id 83so38773896vkd.0 for ; Wed, 19 Oct 2016 11:41:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=dy1n3Lf57YVUETy9Le+5W6dSc8jxI/royfgmjHnHVZ4=; b=SBK/5+D5u/5ayzWqbCevf1pFXeMQIJIOxClHNE/bB+svRXHMB8jfOP7el+1Ai2b2qo 2f18uVRjkuwCFM+nt1MVHrY4TgTMeptRKj/BMNtvW3XzWd4v3sBJUNvwyjv/QZBvveFx h7GLvtwfsrlZTHNiqEtjDVPbfYXxdY4kJznNC7cDhZ2AXTPcczGAntLk1ELH8tR6Mz4X YVypf1HgJrVI6ciDS7VzsIAMi/oHrsSyMAhdqkAQnVmtZVRkcvBcjlLIBa5R++qAW+Vw krB4Y3FOyxRv8COq3Ug8fMuQP2qRCVpDRbCWXeIwEBHc6WvLzMHInThcHacxpLoCtmCp iPAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=dy1n3Lf57YVUETy9Le+5W6dSc8jxI/royfgmjHnHVZ4=; b=QNdBuT6oXcK/9ddVHen4LdbCCbCBIoVMI7dM3FzS0jHYPn5dGchN+IP4Q5IqtmY8y7 hWUuMwiO673e1cY6EfEAMgatBTroOJj5I1exDlFr6dAHKDxvsceE/1lJwC06e5egWOjR Bni2m3a7lYuTCnOXQ3lTE7SKI5sb4d54Zc4kuqBij67qv654ziDcIUIRoJ8NeN9CwJId Hi2R3BMD0gxjaeBsx8hQyomz72ssldF3SEYjWIkTVfb4JP767fvpZlObmew0mGK0CyGy brxiMoD7M0/2E/EYjiSX5Sj6yxaFwV9lX33xV3S2u+/riLhc70YT/wFeAX0Fdoyr3nII x7MQ== X-Gm-Message-State: AA6/9RnuwApgy9vDwGZqY6/BcGxC99xGziXxGaphTEHTdH7+vN7Owm+059tRDjyYBfhzOZLECtLFfatK2pKydw== X-Received: by 10.31.128.2 with SMTP id b2mr5536422vkd.81.1476902469493; Wed, 19 Oct 2016 11:41:09 -0700 (PDT) MIME-Version: 1.0 Received: by 10.103.81.201 with HTTP; Wed, 19 Oct 2016 11:41:08 -0700 (PDT) In-Reply-To: References: Date: Wed, 19 Oct 2016 11:41:08 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Just a bit of a update To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001a1142947a0fea42053f3c2702 --001a1142947a0fea42053f3c2702 Content-Type: text/plain; charset=UTF-8 The muffler we are talking about is a custom made unit. I t was designed to fit INSIDE the RV-3 cowl. We have the exhaust primary tubes shielded in a vented enclosure. The custom muffler fits near the cowl exit. Bill On Wed, Oct 19, 2016 at 10:43 AM, Matt Boiteau wrote: > Maybe I have old information, I thought people were using Aero exhaust > AT2525XL? > > - Matt Boiteau > > On Oct 19, 2016 6:04 AM, "Christian And Tamara Mcdonald" < > flyrotary@lancaironline.net> wrote: > >> H bill >> I had a smaller hot dog style muffler on my Rv and was super quiet >> originally but did rob a small amount of power, so have since gone to a >> larger more free flowing design with a longer Inox muffler and so far have >> around 230hrs on it and still working well. >> >> Cheers >> >> >> On Wednesday, 19 October 2016, William Jepson < >> flyrotary@lancaironline.net> wrote: >> >>> Neil, >>> We have experimented with other mufflers. We have one that is just >>> slightly noisier but it makes 5 more HP. This is a "small port" engine. >>> 1.5" diameter. We find the 185 hp WITH the quiet muffler to be >>> satisfactory. 190 with a different muffler. We have housings with bigger >>> ports which will make more than 200 easily but we are testing for >>> efficiency. Good luck with your own effort. >>> >>> Bill Jepson >>> >>> On Oct 18, 2016 10:04 PM, "Neil Unger" >>> wrote: >>> >>>> Thanks Bill, I would prefer you to spend the time anyway. Thanks for >>>> intro, but have a new one myself which "fits" but I am not expecting much >>>> noise reduction. Will know shortly. Neil. >>>> >>>> On 10/19/2016 8:23 AM, William Jepson wrote: >>>> >>>> Neil, >>>> Revisit the video. The muffler in the video is shown fairly obviously >>>> in one of the pans. That muffler was designed to fit in an RV-3! Pretty >>>> small space there. The slightly odd shape is to allow airflow around it and >>>> out. I have photos of the plane with the engine hung, but I promised my >>>> partner that these would not circulate until the plane is flying and >>>> proven. While I wanted to show some of what is going on we do not want to >>>> be one of many "smoke and mirrors" builders. This is intended to return a >>>> proven platform. I have perfect solidworks drawings of the muffler as well, >>>> but same situation. >>>> >>>> Bill >>>> >>>> On Tue, Oct 18, 2016 at 1:19 PM, Neil Unger < >>>> flyrotary@lancaironline.net> wrote: >>>> >>>>> Bill I get the basic idea, byut what size and volumes are we talking? >>>>> Will it fit under the aeroplane cowl?? That appears to be the problem. >>>>> Neil. >>>>> >>>>> *From:* William Jepson >>>>> *Sent:* Tuesday, October 18, 2016 12:04 PM >>>>> *To:* Rotary motors in aircraft >>>>> *Subject:* [FlyRotary] Re: Just a bit of a update >>>>> >>>>> Neil, >>>>> Helmholtz resonators are used to either amplify or attenuate sounds. >>>>> They describe it fairly well on Wicapedia. The idea is to use chambers that >>>>> tune to the high frequency to kill the highs. The volumes are critical. The >>>>> muffler is a bit clipped in the video, but the volume when the camera is >>>>> looking over the RV-4 with dyno in the background is a good representation. >>>>> Bill >>>>> >>>>> On Mon, Oct 17, 2016 at 4:38 PM, Neil Unger < >>>>> flyrotary@lancaironline.net> wrote: >>>>> >>>>>> Bill, what are Helmholtz principles?? The muffler at 6000 rpm was so >>>>>> quiet it does not even sound like a rotary. Do you have diagram of a >>>>>> description?? Allow that I am an idiot so all details needed. Neil. >>>>>> >>>>>> On 10/18/2016 10:34 AM, William Jepson wrote: >>>>>> >>>>>> Neil, >>>>>> The muffler in the video. It was designed using Helmholtz principles >>>>>> and it works very well at reducing the high frequencies from the rotary. >>>>>> Bill >>>>>> >>>>>> On Mon, Oct 17, 2016 at 4:18 PM, Neil Unger < >>>>>> flyrotary@lancaironline.net> wrote: >>>>>> >>>>>>> Bill, Now you have got my interest, What muffler and where?? >>>>>>> Everything else on the Rotary can be handled, Cooling, mounting, P porting >>>>>>> etc, but mufflers have me beaten. They are the next for me to investigate >>>>>>> particularly how to keep small if possible, The size in most cases affects >>>>>>> how the engine mount can be constructed on that side. >>>>>>> >>>>>>> Thanks in anticip[ation, Neil. >>>>>>> >>>>>>> On 10/18/2016 9:58 AM, William Jepson wrote: >>>>>>> >>>>>>> Charlie, >>>>>>> Pardon my haste in the original reply. The butterflies are very >>>>>>> similar to the original, with the exception that we have devised a new way >>>>>>> to make them that doesn't require drilling through the housings. Can't say >>>>>>> more right now other than we do NOT use epoxy in the housings and NO >>>>>>> sealing problems. Don't expect any. Also we DO NOT weld to the liner as >>>>>>> sometimes pushed by others. I do not believe you can weld to the liner >>>>>>> without catastrophic failure later. I believe you will either fail your >>>>>>> apex seals or crack the weld due to crystallization of the steel. The >>>>>>> muffler is a MAJOR win. It is quieter than a unmuffled Lyc, and >>>>>>> successfully kills the annoying hi frequencies. It is more restrictive than >>>>>>> some but only costs us a few HP. It also fits in an RV-3! I am >>>>>>> experimenting with a larger version in hopes of repeating the success with >>>>>>> a bit less restriction on cowls that aren't as tight as the RV-3 >>>>>>> Bill >>>>>>> >>>>>>> On Mon, Oct 17, 2016 at 3:15 PM, Charlie England < >>>>>>> flyrotary@lancaironline.net> wrote: >>>>>>> >>>>>>>> Hi Bill, >>>>>>>> >>>>>>>> Thanks for the link. I've been following it on the Homebuilt >>>>>>>> Airplanes forum; are you 'billsrv4' over there? >>>>>>>> >>>>>>>> I've been trying to find a throttle mechanism in the video, but >>>>>>>> don't see one. Are they using the custom 'in the housing' butterflies, like >>>>>>>> the original Powersport engine? >>>>>>>> >>>>>>>> Have you heard it run in person? If so, does the muffler work as >>>>>>>> well as it seems to in the video? (Hard to know how much the audio is >>>>>>>> clipped in level on a recording.) >>>>>>>> >>>>>>>> Thanks, >>>>>>>> >>>>>>>> Charlie >>>>>>>> >>>>>>>> On Mon, Oct 17, 2016 at 4:52 PM, William Jepson < >>>>>>>> flyrotary@lancaironline.net> wrote: >>>>>>>> >>>>>>>>> Since it has been so quiet thought I would make some noise. >>>>>>>>> Try this package on for size. >>>>>>>>> https://www.youtube.com/watch?v=EfreUJt-Fsk. >>>>>>>>> Think you will find it interesting. >>>>>>>>> Bill >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> >>>> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: http://mail.lancaironline. >> net:81/lists/flyrotary/List.html >> >> --001a1142947a0fea42053f3c2702 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The muffler we are talking about is a custom made unit. I = t was designed to fit INSIDE the RV-3 cowl. We have the exhaust primary tub= es shielded in a vented enclosure. The custom muffler fits near the cowl ex= it.
Bill

On Wed, Oct 19, 2016 at 10:43 AM, Matt Boiteau <= ;flyrotary= @lancaironline.net> wrote:
=

Maybe I have old information, I thought people were using Ae= ro exhaust AT2525XL?

- Matt Boiteau


On Oct 19, 2016 6= :04 AM, "Christian And Tamara Mcdonald" <flyrotary@lancaironline.net= > wrote:
H billI had a smaller hot dog style muffler on my Rv and was super quiet origi= nally but did rob a small amount of power, so have since gone to a larger m= ore free flowing design with a longer Inox muffler and so far have around 2= 30hrs on it and still working well.

Cheers


On Wednesday, 19 October 2016, William Jepson <flyrotary@lancaironline.= net> wrote:

Neil, We have experimented with other mufflers. We have one that is just slightly= noisier but it makes 5 more HP. This is a "small port" engine. 1= .5" diameter. We find the 185 hp WITH the quiet muffler to be satisfac= tory. 190 with a different muffler. We have housings with bigger ports whic= h will make more than 200 easily but we are testing for efficiency. Good lu= ck with your own effort.

Bill Jepson


On Oct 18, 2016 1= 0:04 PM, "Neil Unger" <flyrotary@lancaironline.net> = wrote:
=20 =20 =20

Thanks Bill,=C2=A0 I would prefer you to spend the time anyway.=C2= =A0 Thanks for intro, but have a new one myself which "fits" bu= t I am not expecting much noise reduction.=C2=A0 Will know shortly.=C2=A0 Ne= il.


On 10/19/2016 8:23 AM, William Jepson wrote:
Neil,
Revisit the video. The muffler in the video is shown fairly obviously in one of the pans. That muffler was designed to fit in an RV-3! Pretty small space there. The slightly odd shape is to allow airflow around it and out. I have photos of the plane with the engine hung, but I promised my partner that these would not circulate until the plane is flying and proven. While I wanted to show some of what is going on we do not want to be one of many "smoke and mirrors" builders= . This is intended to return a proven platform. I have perfect solidworks drawings of the muffler as well, but same situation.

Bill

On Tue, Oct 18, 2016 at 1:19 PM, Neil Unger <flyrotary@lancaironline.net>= ; wrote:
Bill I get the basic idea, byut what size and volumes are we talking?=C2=A0 Will it fit under the aeroplane cowl??=C2=A0 That appears to be the problem.= =C2=A0 Neil.
=C2=A0
Sent: Tuesday, October 18, 2016 12:04 PM
Subject: [FlyRotary] Re: Just a bit of a update
=C2=A0
Neil,=C2=A0
Helmholtz resonators are used to either amplify or attenuate sounds. They describe it fairly well on Wicapedia. The idea is to use chambers that tune to the high frequency to kill the highs. The volumes are critical. The muffler is a bit clipped in the video, but the volume when the camera is looking over the RV-4 with dyno in the background is a good representation.
Bill
=C2=A0
On Mon, Oct 17, 2016 at 4:38 PM, Neil Unger <flyrotary@lancaironline.net> wrote:

Bill, what are Helmholtz principles??=C2=A0 The muffler at 6000 rp= m was so quiet it does not even sound like a rotary.=C2=A0 Do you have diagram = of a description??=C2=A0 Allow that I am an idiot so all details needed.=C2=A0 Neil.<= br>

=C2=A0
On 10/18/2016 10:34 AM, William Jepson wrote:
Neil,
The muffler in the video. It was designed using Helmholtz principles and it works very well at reducing the high frequencies from the rotary.
Bill
=C2=A0
On Mon, Oct 17, 2016 at 4:18 PM, Neil Unger <fl= yrotary@lancaironline.net> wrote:

Bill,=C2=A0 Now you have g= ot my interest,=C2=A0 What muffler and where??=C2=A0 Everything else on the Rotary can be handled,=C2= =A0 Cooling, mounting, P porting etc, but mufflers have me beaten.=C2=A0 They are the next for me to investigate particularly how to keep small if possible,=C2=A0 The size in most cases affects how the engine mount can be constructed on that side.

Thanks in anticip[ation,=C2=A0 Neil.= =C2=A0

=C2=A0
On 10/18/2016 9:58 AM, William Jepson wrote:
Charli= e,
Pardon my haste in the original reply. The butterflies are very similar to the original, with the exception that we have devised a new way to make them that doesn't require drilling through the housings. Can't say more right now other than we do NOT use epoxy in the housings and NO sealing problems. Don't expect any. Also we DO NOT weld to the liner as sometimes pushed by others. I do not believe you can weld to the liner without catastrophic failure later. I believe you will either fail your apex seals or crack the weld due to crystallization of the steel. The muffler is a MAJOR win. It is quieter than a unmuffled Lyc, and successfully kills the annoying hi frequencies. It is more restrictive than some but only costs us a few HP. It also fits in an RV-3! I am experimenting with a larger version in hopes of repeating the success with a bit less restriction on cowls that aren't as tight as the RV-3
Bill
=C2=A0
On Mon, Oct 17, 2016 at 3:15 PM, Charlie England &= lt;flyrotary@lancaironline.net> wrote:
= Hi Bill,
=C2=A0
Thanks for the link. I've been following it on the Homebuilt Airplanes forum; are you 'billsrv4'= ; over there?
=C2=A0
I've bee= n trying to find a throttle mechanism in the video, but don't see one= . Are they using the custom 'i= n the housing' butterflies, like the original Powersport engine?
=C2=A0
Have you heard it run in person? If so, does the muffler work as well as it seems to in the video? (Hard to know how much the audio is clipped in level on a recording.)
=C2=A0
Thanks,
=C2=A0
Charlie
=C2=A0
On Mon, Oct 17, 2016 at 4:52 PM, William Jepson <flyrotary@lancaironline.net> wrote:
= Since it has been so quiet thought I would make some noise.
Try this package on for size.
Think you will find it interesting.
Bill
=C2=A0
=C2=A0

=C2=A0

=C2=A0



--
Homepage:=C2=A0 http://www.flyrotary.com/
Archive and UnSub:=C2=A0 =C2=A0http://mail= .lancaironline.net:81/lists/flyrotary/List.html


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