X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=H+OlPNQi c=1 sm=1 tr=0 a=1Xv/HvWHg90e81bPS5VMkw==:117 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=MeAgGD-zjQ4A:10 a=aOWVIxkx-zkA:10 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=7g1VtSJxAAAA:8 a=sHkgzL93CRzBp-Bib4oA:9 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=f-C88RauIkJ4AciVK5YA:9 a=UKtScncklCX_TJCA:21 a=Urk15JJjZg1Xo0ryW_k8:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "Andrew Martin andrew@martinag.com.au" Received: from mail-qt1-f173.google.com ([209.85.160.173] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 13162444 for flyrotary@lancaironline.net; Mon, 11 Nov 2019 00:56:46 -0500 Received-SPF: none receiver=logan.com; client-ip=209.85.160.173; envelope-from=andrew@martinag.com.au Received: by mail-qt1-f173.google.com with SMTP id 30so14474525qtz.12 for ; Sun, 10 Nov 2019 21:56:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=martinag-com-au.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=S1lsTACX2fY4YoPoPRlgmpMOZgKfAXF8jszQlDtoTlE=; b=cDxaZVG4N1Ku8XaZ6Ttyh00/e5UWM5yPznznP5N6LfxxIQOxvC/5mzdCTfhN9h5yYY VjgEeAQp0HSfdI4Fk/GupaUjLGyL0/LbKDp4TnrtaLfzyhjjRIJJ1CSst2j/3SR447jY YuUVy+kEj59kt1FB7nMZfy0OTw+cGeywZQshUjttmcqtHmXtPmkjS31Cd2rXT6+sjd7g /Pw/XMUd/qmmUxRVDnbdA7TrqU8NrYiL/4S7U1LV1i6ydaZSm/88XsnfbSGZyqYmAo+r O5WNZNcI+SDjfWG6GbyxzTI3zCCUhUFvDm0gp1RjHiqqg6Fjl6pz1ms7fu3bSO8ibh5W pJ+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=S1lsTACX2fY4YoPoPRlgmpMOZgKfAXF8jszQlDtoTlE=; b=O4+9J7CT7n90xZEU7C+8LRIWE3H8H5jwYOc7K3vI13B9Ia5KSF5BT0kWLcsFMi/zgT CnnG63j+TZyV2z5DlaHzeL+HRYRfZLM8V1UmvhHk/tofDmMTG0ErX+n3hv5bpV60U9Rs ZUNAEJClm6w4aMIY3GP85jBCtTLcy6UjIX4jBL1DrHTwcQAxrhYDiTTZyAWg+7jam0cS XrZNUOF6KAf6Eu9Xgz5dY2ulvutCWIqA2hWnvc3YpwxeQ57FD2TZnDQNjHujONa/9k/T p7EzMMv7//wcj5LcnQqxW/1vh0Dt4+C+LZqck4JDg9pH9v6EFMaXsf619kp6so/xxcAU BgEA== X-Gm-Message-State: APjAAAUGYOKROWmdFKBj8KZr+gfLOJQeD2ALm/C4xrRT9nJol+HqAGeY 8uKfM9QiQexb1gIy4AkQs5q8b3lEDMP7182PNyzwkLY= X-Google-Smtp-Source: APXvYqzgysiaPayveHpinOEdv0xTdpGluYCZzfrFAxxTN5GiozlyABqWn7JqJECylibWrUEyhxEMfWkEQSrbJUvauzY= X-Received: by 2002:ac8:22c4:: with SMTP id g4mr24102321qta.45.1573451791168; Sun, 10 Nov 2019 21:56:31 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Date: Mon, 11 Nov 2019 13:56:18 +0800 Message-ID: Subject: Re: [FlyRotary] Exhaust setups To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="00000000000015884305970bcb71" --00000000000015884305970bcb71 Content-Type: text/plain; charset="UTF-8" Matt. Did I read that right. Your 4" tube is open at the end? Would that not make it try to emulate a trumpet. I would close the outlet end completely then cut an outlet in the 4" at the inlet end. You end up with a very effective Schertz pipe exhaust. On Mon, 11 Nov. 2019, 11:38 am Matt Boiteau mattboiteau@gmail.com, < flyrotary@lancaironline.net> wrote: > What are you guys running for exhaust? The thing is stupid loud and can > barely talk on radio. Headset is LightSpeed wireless Tango's. Their ANR > does not work well with the pitch of the rotary. Will try a Bose headset > tomorrow. > > I have 2.5" exhaust leaving the cowl. (ex1.jpg) It comes down and centers > the bottom of the plane into a 4" outer pipe. (ex2.jpg) The 4" outer pipe > (5ft long) is open to the free air and exits behind the rear bulkhead. The > 2.5" converts to a 3ft long perforated pipe (ex3.jpg) and exits inside the > 4" outer pipe. For fun, I filled it full of ceramic fiber insulation mat, > which did help a little until it blew all out. > > > - Matt Boiteau > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > --00000000000015884305970bcb71 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Matt. Did I read that right. Your 4" tube is open at= the end? Would that not make it try to emulate a trumpet.
I would close the outlet end completely then cut an outlet in the 4" = at the inlet end. You end up with a very effective Schertz pipe exhaust.

On Mon, 11 Nov. 2019, 11:38 am Matt Boiteau mattboiteau@gmail.com, <flyrotary@lancaironline.net> wrote:
What are you= guys running for exhaust? The thing is stupid loud and can barely talk on = radio. Headset is LightSpeed wireless Tango's. Their ANR does not work = well with the pitch of the rotary. Will try a Bose headset tomorrow.
I have 2.5" exhaust leaving the cowl. (ex1.jpg) =C2=A0It = comes down and centers the bottom of the plane into a 4" outer pipe. (= ex2.jpg) The 4" outer pipe (5ft long) is open to the free air and exit= s behind the rear bulkhead. The 2.5" converts to a 3ft long perforated= pipe (ex3.jpg) and exits inside the 4" outer pipe. For fun, I filled = it full of ceramic fiber insulation mat, which did help a little until it b= lew all out.


- Matt Boite= au
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Homepage:=C2=A0 http://www.flyrotary.com/
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