X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "Stephen Izett stephen.izett@gmail.com" Received: from mail-pf1-f172.google.com ([209.85.210.172] verified) by logan.com (CommuniGate Pro SMTP 6.4.0) with ESMTPS id 2555655 for flyrotary@lancaironline.net; Mon, 30 Oct 2023 18:11:42 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.210.172; envelope-from=stephen.izett@gmail.com Received: by mail-pf1-f172.google.com with SMTP id d2e1a72fcca58-6b9af7d41d2so4363202b3a.0 for ; Mon, 30 Oct 2023 15:11:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1698703884; x=1699308684; darn=lancaironline.net; h=message-id:in-reply-to:to:references:date:subject:mime-version:from :from:to:cc:subject:date:message-id:reply-to; bh=GZEh5OWhD1TWoURrtbJmOSiX26a/LjNKFTSWhkevqBY=; b=EWjPaBU89VicmKbawJwOn+dvTLBzEn7A3BPylQwnt7OvbGz6+ODnOq0hWLfegUeQ08 EppHKPHOvMcNKFo/ca2lhHivX2qPyv0AcgIdJfJ9QlXyTHyOqYfzx4aPvaWeHQUsRBn/ PHmYLTzljwU5la6u/GN6TA1NTQToB9NRoVzl9YvC+bny2juHxzC1HBgovZ1gXDgossT0 sYgj18j8WEvBTCD36suqux9UXw5YqS6KCkD6Vn27DFhh39Y9gDplDA2tBBos0e3pdGHd oD4P4Dg1spcssEbuBdsK+1Acfee0hDeQTH7Wl7o/bGP0Lbk6pzuVqPzQ+ZHS33Duk4DP Tsfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698703884; x=1699308684; h=message-id:in-reply-to:to:references:date:subject:mime-version:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=GZEh5OWhD1TWoURrtbJmOSiX26a/LjNKFTSWhkevqBY=; b=bOnhDfTE+L0QkEwyF1VIMe8SAq2jx5QB4bx4SK4vYnaYkmOesTkbMFVrxByDyq1M6W amYwCE0//KoIMNImMeRBIW+ayCjGMsPVloYHYLbuzD/wTgNkHiX4cX6LL9ClqTnaa5V1 I63mKhPXk/PVAc99ikcz4UMIg14AL0VQjH5HwJGrbROMlSFWJxS8Z29zJzeLxit9Mjp8 WX4jm42EEFJ77XAgVl7JbhhnhTjgo9+oCWdDMBdex2pWltLT7eHpPSoW3t4xJiX2/XOT 8SJ6qtLxmjNhujxs5iA6X53Y9EDz2G7HrqeUnn6KoRCb8dZEnZ9q+auNueeHKAxcXc6c e6zg== X-Gm-Message-State: AOJu0Ywc8QMR143U1gwgwBnfeuqpT9u5Fac0J7EnUTILb+iov0cnFdip DS11GRJZ4ZG9T1sObruoQSJIF+zhHx1YIw== X-Google-Smtp-Source: AGHT+IHA7fK6pz5kfrc5LPut9SPqsRewU2bErRYh3t4kMhiAYGpmjwz/Lzy1HaoyEcQsUX2Fk7E0tw== X-Received: by 2002:a05:6a00:1593:b0:6be:2901:2cd with SMTP id u19-20020a056a00159300b006be290102cdmr10737357pfk.10.1698703883143; Mon, 30 Oct 2023 15:11:23 -0700 (PDT) Return-Path: Received: from smtpclient.apple (220-235-72-153.dyn.iinet.net.au. [220.235.72.153]) by smtp.gmail.com with ESMTPSA id k1-20020a628e01000000b006bdb0f011e2sm12569pfe.123.2023.10.30.15.11.21 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 30 Oct 2023 15:11:22 -0700 (PDT) Content-Type: multipart/alternative; boundary="Apple-Mail=_1A4D965F-F3EE-44D4-8314-D926E288B5CD" Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3774.100.2.1.4\)) Subject: Re: [FlyRotary] Updates on Muffler Experiences? Date: Tue, 31 Oct 2023 06:11:02 +0800 References: To: Rotary motors in aircraft In-Reply-To: Message-Id: X-Mailer: Apple Mail (2.3774.100.2.1.4) --Apple-Mail=_1A4D965F-F3EE-44D4-8314-D926E288B5CD Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Thanks Andrew I like what you did. Nice and compact. Steve > On 30 Oct 2023, at 11:10=E2=80=AFam, Andrew Martin = andrew@martinag.com.au wrote: >=20 > Hi Steve > here you go. couple of qualifiers, Tin can is only a heat shield,is = standard milk tin so gives idea of scale. muffler section was made from = thick wall SS tube. Exhaust exits high on cowl, This is my own = requirement as I live on a farm and didn't want grass fires in summer. = Tip is visible from cockpit so gives visual clue as to how smooth engine = is running, (and it works for the pt6 in the Thrush). If I done it again = might consider having tailpipe go vertical down through the cowl, would = get heat away from intake manifold and keep the peanut gallery at the = aeroclub happy. > Andrew > >=20 >=20 > On Mon, 30 Oct 2023 at 7:06 am, Stephen Izett stephen.izett@gmail.com = > wrote: >> Hi Andrew >>=20 >> Do you have a photo of your engine/mufler? >>=20 >> Steve Izett >>=20 >>=20 >>=20 >> > On 29 Oct 2023, at 10:31=E2=80=AFpm, Andrew Martin = andrew@martinag.com.au = > = wrote: >> >=20 >> > Hi Doug,=20 >> > My setup is for a Renesis so bit different to an 86 13b, what I = found worked well is a short & compact muffler, all homemade, a 60mm = perforated ss tube welded to the mazda renesis exhaust manifold that was = shortened as much as possible. I perforated the 60mm tube with 10mm = drilled holes, enough so area of drilled holes is same as pipe inlet. A = 100mm ss tube covers the 60mm tube and outlet of 100mm is at same end as = inlet of 60mm, this is important to send sound waves back to source = (works similar theory to ANR headset apparently). muffler is short, = approx 150mm to keep it rigid & fit the space next to the psru. end = plates of muffler were cut from 6mm plate & fully welded to both inner & = outer tubes and covered with lightweight tin can as heatshield. >> >=20 >> > If I was using p port exhaust I would mount individual mufflers = directly to each port, inner pipe same size same as port, would look = like 2 cans protruding from side of engine, connect short tailpipes = (same volume as inner perforated pipe) as close to engine end of outer = pipe as possible to exit cowl. Idea is to send sound waves straight back = to where they come from without restricting gas flow. >> > Probably as clear as mud, but my 2 cents worth, works a treat. >> > Cheers >> > Andrew Martin >>=20 >>=20 >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html --Apple-Mail=_1A4D965F-F3EE-44D4-8314-D926E288B5CD Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Thanks = Andrew
I like what you did. Nice and compact.
Steve

On 30 Oct 2023, at 11:10=E2=80=AFam, Andrew Martin = andrew@martinag.com.au <flyrotary@lancaironline.net> = wrote:

Hi Steve
here you go. couple of qualifiers, Tin can is = only a heat shield,is standard milk tin so gives idea of scale. muffler = section was made from thick wall SS tube. Exhaust exits high on cowl, = This is my own requirement as I live on a farm and didn't want grass = fires in summer. Tip is visible from cockpit so gives visual clue = as to how smooth engine is running, (and it works for the pt6 in the = Thrush). If I done it again might consider having tailpipe go vertical = down through the cowl, would get heat away from intake manifold and keep = the peanut gallery at the aeroclub = happy.
Andrew
<IMG-0186.JPG>


On Mon, 30 Oct 2023 at 7:06 am, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> = wrote:
Hi Andrew

Do you have a photo of your engine/mufler?

Steve Izett



> On 29 Oct 2023, at 10:31=E2=80=AFpm, Andrew Martin andrew@martinag.com.au <flyrotary@lancaironline.net> wrote:
>
> Hi Doug,
> My setup is for a Renesis so bit different to an 86 13b, what I = found worked well is a short & compact muffler, all homemade, a 60mm = perforated ss tube welded to the mazda renesis exhaust manifold that was = shortened as much as possible. I perforated the 60mm tube with 10mm = drilled holes, enough so area of drilled holes is same as pipe = inlet.  A 100mm ss tube covers the 60mm tube and outlet of 100mm is = at same end as inlet of 60mm, this is important to send sound waves back = to source (works similar theory to ANR headset apparently). muffler is = short, approx 150mm to keep it rigid & fit the space next to the = psru. end plates of muffler were cut from 6mm plate & fully welded = to both inner & outer tubes and covered with lightweight tin can as = heatshield.
>
> If I was using p port exhaust I would mount individual mufflers = directly to each port, inner pipe same size same as port, would look = like 2 cans protruding from side of engine, connect short tailpipes = (same volume as inner perforated pipe) as close to engine end of outer = pipe as possible to exit cowl. Idea is to send sound waves straight back = to where they come from without restricting gas flow.
> Probably as clear as mud, but my 2 cents worth, works a treat.
> Cheers
> Andrew Martin


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