X-Virus-Scanned: clean according to Sophos on Logan.com From: "William Jepson" Received: from mail-vk0-f43.google.com ([209.85.213.43] verified) by logan.com (CommuniGate Pro SMTP 6.1.12) with ESMTPS id 9046089 for flyrotary@lancaironline.net; Tue, 18 Oct 2016 17:23:48 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.213.43; envelope-from=wrjjrs@gmail.com Received: by mail-vk0-f43.google.com with SMTP id b186so9416047vkb.1 for ; Tue, 18 Oct 2016 14:23:47 -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=jKHaOK6t30YTppQgrhbfZtKCKuIJFtYl2S+TYLVr8jE=; b=P6chB5fFH9tZhU+Hx51qzYOqr8JrIRdRTtFMUddaBN9wkd2UnKUTPj3N0sHV+BWSyL nKc/gjzugIxmUxPFI1TarFBgrGsPmNlVWVB2NONnkQ0IGvaQ++hMfyMeNbbbkVUqa5JC vbZz5MQTmF2sIH6bJ6a7lAu6NrhLshP1rM2A+/q6rXxPrtjzNE03nS5YfSxVw9H7DDf7 wnKUnpOCBIHJ2Z/dg1VO7LJojdmEVhxbdQkanYDXOlarDIe9QtgZCb2Ri92fEACQXkpo 3T85JfbAJPbsquxmi9wbfTeE4YATSUmvEOckVrHOAVxmNSA5r+PzEHIdY2VFJScmeG+S SAtA== 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=jKHaOK6t30YTppQgrhbfZtKCKuIJFtYl2S+TYLVr8jE=; b=IDhUTqxc2Pv/LxxQvtRzABCgUXdQID0ydCnfMPbR25SLzjEgGHz9DqHVoESBz2B5gK 63NYKzWtETsEsYR9p4tGoxpNtXEE32W467QB8b0li1FJC/H+P+BmZnw5fAOfE3rKaUsx ya2r/yGTa9lObSz406pDohLaqPjUwaVOIJNzbMjOGJjctMY9wQUTQ3ubDWb8v4xvQFoZ f8IRGxaqRwNTl/q99Js+Z4gRGZdwVyoKJv8NqyCdWEeR3yp/8DiRUNf+IOv2qstWyeMD NN1AsNRhyh7hEwsvqVejLeVPeiSQBJuWz29Iyt38/Z6CsiDKinypqnXJAcw6W8USnumz we7Q== X-Gm-Message-State: AA6/9RlIn67/Vi0RgOvnXdH8K6fipts9Lm+eScbsA+9KSNLZhgJQJ78cbzIvf9umeC/z/NaIKhX1AHYWMwoTlA== X-Received: by 10.31.167.15 with SMTP id q15mr2724589vke.85.1476825810732; Tue, 18 Oct 2016 14:23:30 -0700 (PDT) MIME-Version: 1.0 Received: by 10.103.81.201 with HTTP; Tue, 18 Oct 2016 14:23:30 -0700 (PDT) In-Reply-To: References: Date: Tue, 18 Oct 2016 14:23:30 -0700 Message-ID: Subject: Re: [FlyRotary] Re: Just a bit of a update To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=001a11427c2ed81a2f053f2a4dfd --001a11427c2ed81a2f053f2a4dfd Content-Type: text/plain; charset=UTF-8 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 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 > 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 >> 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 >>>>> >>>> >>>> >>> >>> >>> >>> >> >> >> > --001a11427c2ed81a2f053f2a4dfd Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Neil,
Revisit the video. The muffler in the video is s= hown 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 ai= rflow around it and out. I have photos of the plane with the engine hung, b= ut 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 no= t want to be one of many "smoke and mirrors" builders. This is in= tended to return a proven platform. I have perfect solidworks drawings of t= he 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=20 Will it fit under the aeroplane cowl??=C2=A0 That appears to be the=20 problem.=C2=A0 Neil.
=C2=A0
Neil,=C2=A0=20
Helmholtz resonators are used to either amplify or attenuate sounds. T= hey=20 describe it fairly well on Wicapedia. The idea is to use chambers that tune= to=20 the high frequency to kill the highs. The volumes are critical. The muffler= is a=20 bit clipped in the video, but the volume when the camera is looking over th= e=20 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 rpm wa= s so=20 quiet it does not even sound like a rotary.=C2=A0 Do you have diagram of = a=20 description??=C2=A0 Allow that I am an idiot so all details needed.=C2=A0= =20 Neil.

=C2=A0
On 10/18/2016 10:34 AM,=20 William Jepson wrote:
Neil,=20
The muffler in the video. It was designed using Helmholtz principl= es=20 and it works very well at reducing the high frequencies from the=20 rotary.
Bill
=C2=A0
On Mon, Oct 17, 2016 at 4:18 PM, Neil Unger = <flyrotary@lancaironline.net> wrote:

Bill,=C2=A0 Now you have got my interest,=C2=A0 What muffler and= =20 where??=C2=A0 Everything else on the Rotary can be handled,=C2=A0 Coo= ling,=20 mounting, P porting etc, but mufflers have me beaten.=C2=A0 They are = the=20 next for me to investigate particularly how to keep small if=20 possible,=C2=A0 The size in most cases affects how the engine mount c= an be=20 constructed on that side.

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

=C2=A0
On=20 10/18/2016 9:58 AM, William Jepson wrote:
Charlie,=20
Pardon my haste in the original reply. The butterflies are ver= y=20 similar to the original, with the exception that we have devised a = new=20 way to make them that doesn't require drilling through the hous= ings.=20 Can't say more right now other than we do NOT use epoxy in the = housings=20 and NO sealing problems. Don't expect any. Also we DO NOT weld = to the=20 liner as sometimes pushed by others. I do not believe you can weld = to=20 the liner without catastrophic failure later. I believe you will ei= ther=20 fail your apex seals or crack the weld due to crystallization of th= e=20 steel. The muffler is a MAJOR win. It is quieter than a unmuffled L= yc,=20 and successfully kills the annoying hi frequencies. It is more=20 restrictive than some but only costs us a few HP. It also fits in a= n=20 RV-3! I am experimenting with a larger version in hopes of repeatin= g the=20 success with a bit less restriction on cowls that aren't as tig= ht as the=20 RV-3
Bill
=C2=A0
On Mon, Oct 17, 2016 at 3:15 PM, Charlie= England=20 <flyrotary@lancaironline.net> wrote:
Hi Bill,=20
=C2=A0
Thanks for the link. I've been following it on the Homeb= uilt=20 Airplanes forum; are you 'billsrv4' over there?
=C2=A0
I've been trying to find a throttle mechanism in the vid= eo, but=20 don't see one. Are they using the custom 'in the housing&= #39; butterflies,=20 like the original Powersport engine?
=C2=A0
Have you heard it run in person? If so, does the muffler wor= k as=20 well as it seems to in the video? (Hard to know how much the audi= o is=20 clipped in level on a recording.)
=C2=A0
Thanks,
=C2=A0
Charlie
=C2=A0
On Mon, Oct 17, 2016 at 4:52 PM, Willi= am Jepson=20 <flyrotary@lancaironline.net> wrote:
Since it has been so quiet thought I would mak= e some=20 noise.=20
Try this package on for size.
Think=20 you will find it interesting.
Bill
=C2=A0
=C2=A0

=C2=A0

=
=C2=A0

--001a11427c2ed81a2f053f2a4dfd--