X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=H+OlPNQi c=1 sm=1 tr=0 a=sv1LXgO2Gz9uSgF+vmu2Og==:117 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=MeAgGD-zjQ4A:10 a=XQxfBrvntfMA:10 a=r77TgQKjGQsHNAKrUKIA:9 a=pGLkceISAAAA:8 a=o1OHuDzbAAAA:8 a=Ia-xEzejAAAA:8 a=7g1VtSJxAAAA:8 a=fT4gx2zTWToDAB9LZ6cA:9 a=QEXdDO2ut3YA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=4PR2P7QzAAAA:8 a=GyP-zp79JxzVaWVmXgEA:9 a=sSenYd0n38L9kyqh:21 a=_W_S_7VecoQA:10 a=5YQ6H4ZxyGn-KoBYtt8s:22 a=Urk15JJjZg1Xo0ryW_k8:22 a=grOzbf7U_OpcSX4AJOnl:22 a=4dqwQCo7Po2mVW515mGf:22 From: "Finn Lassen finn.lassen@verizon.net" Received: from sonic313-9.consmr.mail.ne1.yahoo.com ([66.163.185.32] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 13165042 for flyrotary@lancaironline.net; Mon, 11 Nov 2019 14:33:45 -0500 Received-SPF: pass receiver=logan.com; client-ip=66.163.185.32; envelope-from=finn.lassen@verizon.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=verizon.net; s=a2048; t=1573500808; bh=7IkzvO23hyuYZXSApIEx60PH3sTonRpbK9E1K/pevz8=; h=Subject:To:References:From:Date:In-Reply-To:From:Subject; b=uARGObjCC+7FIBthcLjcCmB+6SeD5PS+8Bl7a+bP259tfCqzR47C/SUK7t3S7nHqegLV8mG8RSeMv0ZrhwBoeDVrlKN31qfeBT9W+pz3ZSuIAg2sRNkFP4ChTCnCTpLY0MPSXVS2BY/COpJYEbcgJw8dIz0MaKUYXIz1AzP2YJvAX+vMObHr/dCIIx2lS+EXpAYXUsT5QnOJgaJVegDxW/w+frizNDy9l4iA7vjPKG9jrxJe20Y1m9k601HBihg+2U6mDH5szk/aI79LAc9y26DVRxWghT2fi+/pw9iVYcZL7yxxvF/hkZTMgZ9YwtD1kjFWu15VxcEvg/gCj8S3xA== X-YMail-OSG: LErzJicVM1nyNHHI.bs8BwqZIHVleHqFs4bmjjzjm_kPMqDVc8kSTmR6iXGIVGA 3_MaP4R4KgxZtTmDKH2p0rooqBw7bkXaHksY9qBE3.gkGRSPoIRZrBkPCg9KBG.mO.Ma6nmwaYo1 6h21.mx2QG4OSGHWL3PsetbEgKvPwlljXLjAVsM_MhLSoiaBuzEJTSQwztUW2WRXcANTfH.ExMyj .oeDfEQTCwFZzLejStu.HWRtFVtNcB81PMCrdizQAl2CJh9UiZ0NqmXZjRVKSZeN6C1x7WWfHKov M0oj8WmyUYAw0j7kD0R37QaBW3m56zM.heOAqZt0S1s475OR65ls_B33tfhVkdMx6Dfh74KR3BbZ ZTOClCuOXbK4IBk_eXiStRvqZiMGnIW2dtZIxSTE2yt179l.XEbAXggFQ4Nl2LvfJo7vfvbKJ3RS ySSHKJ0BkcJJ0QKMy0HSAsLO36Hz7.LAiugODc3TPm6BetMkBxjLv9gbBAbo0vWGYDRqjp0VzZt0 BvY_Wu28pfQgA0P0boQ6iqdf4jD6jAMpQIwTi01xkgUh_AmiqF0fG9XcCzhxNfVVAhu9_n0IHUxV M.nVNGhoNGLEKFL2jKpWOuWnAxskrY3k0amcZwGCNbwIi4_K92TC2bVbQFTcOWyEMpPaTn2OZc.m oKF5OMR6VOB5jc3uhE1JzoOWwiWssJMhu6_16xhB.9bKq7LpgXSP5z8UAo6QtQ3S6ubs5NUBHJYh qliF1HjfWua1FBnuRceGT6OkMnf0cOf7mVuFL8PPgQ3AeN30_cJjRqLXY5UiRAsUAsRjliAvUw1n 8BXODyIummpFGpTLs2aELPZNj6tohh7iXefPYGRlU5qvisDUH3O3t6lKKUkS9jx3aZHJuJyDMT.H Ss_JCW3IcVDRYDf7jOFwI7R13IDSQFQqGg0ZM_Ry5CPA3c2aE9zSLL8ZvjbM7fj1sYkGRpkIPFid 3q4ISF.0turiDWeRruintnVd1Rs5gOSU4BjgyTtsr4hKFGjdfUGKt1gOkp7OO3QifH.MHw3n2Cgc t1.bGuJwsglmTVBxbTArGxahZDLQl8xW.weN0tLBrqJF0MHmPCotRNNTc7WCOv_nUOa4_Tbc4AZA QMu.Iv67IhevVXB53QEC_8OzOficDS2KDvtMeD.PkTAqmHVVrx_CYGGMQxDaxgQrA4.67FGpL5YU P6GlqZKxrTMxSd.PgO0431dzeMHoAWb6r7FbE7jsLZC9XYQ9lIuLv5QHgqSuSSztT8MYTZsqRf.s WRXx_dBpiLC7s79jpKgur98tE0B3mMfhdP1k1pIHJG69iRbOAgThgp0OBIiJljUfUV3vZBWSkEc3 qV6RSS4pHNmDCfOXYMKbAFbXfQ_qN1uGEQUTl.2QF6wz5rcWZ.24vVKwHbPgDbobmm74kBYum1qQ - Received: from sonic.gate.mail.ne1.yahoo.com by sonic313.consmr.mail.ne1.yahoo.com with HTTP; Mon, 11 Nov 2019 19:33:28 +0000 Received: by smtp403.mail.bf1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 4da6d86e103789670bcf294fb72306cc; Mon, 11 Nov 2019 19:33:23 +0000 (UTC) Subject: Re: [FlyRotary] Re: Exhaust setups To: Rotary motors in aircraft References: Message-ID: Date: Mon, 11 Nov 2019 14:33:16 -0500 User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/alternative; boundary="------------2C9F10B185D0EE17B76B34FE" Content-Language: en-US X-Mailer: WebService/1.1.14680 hermes Apache-HttpAsyncClient/4.1.4 (Java/1.8.0_181) Content-Length: 15216 This is a multi-part message in MIME format. --------------2C9F10B185D0EE17B76B34FE Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit No, it's simply a 2.5" tube welded onto the outlet of the Hushpower "muffler". If I remember correctly, the innards of the Hushpower muffler were all blown out when I did this. But the key to noise reduction in the cockpit seems to be to get the exhaust pointed away from the cockpit. Granted, probably doesn't do much for people on or near the airport :) Yes, it may increase drag to have the plume(s) pointed down instead of aft. I didn't try to measure that. Finn On 11/11/2019 12:40 PM, Matt Boiteau mattboiteau@gmail.com wrote: > It's behind the rear bulkhead by a ft or so. The perforated store > bought sheet is extremely holey, found in typical mufflers. I do have > a 4ft 2.5" solid tube I bought just incase i drill my own holes. > > Is your exhaust tube inside a surrounding tube? Or you just extended > the current exhaust (2.5" or 3"?) 3 ft more, capped off the end of it? > > - Matt Boiteau > > On Mon, Nov 11, 2019, 11:20 Finn Lassen finn.lassen@verizon.net > > wrote: > > On?? my RV-3B I added a 3' long pipe with 1/8" holes drilled in > the bottom of it (faced down). Tube closed at the end. Area of the > 1/8" holes add up to the cross section are of the tube. > That did reduce the noise in the cockpit noticeably. > > Is your final exit well behind the cockpit? If so, the sound must > be transmitted through the surrounding (outer) pipe. > > Finn > > On 11/11/2019 10:29 AM, Matt Boiteau mattboiteau@gmail.com > wrote: >> Yes more or less like the coax muffler. Instead of drilling a few >> holes here and there, I bought a perforated sheet and welded it >> into a tube. I wanted to have it open on both ends, to create a >> vacuum and help suck the air out of the cowl. But right now to >> make flights enjoyable, I might close up the ends and see how >> that works. >> >> Is anyone running a coax muffler ? Because it's extremely loud in >> my case. >> >> I did buy the??Aero Exhaust AT2525XL and it worked great while >> doing all my ground testing, but the 6" outer shell was just to >> big to fit under the plane. Sadly I brought it back home to >> Canada and haven't flown with it yet here in FL. I'll pack it in >> my suitcase next trip down. >> >> The racing beat presilencer is suppose to be good. I believe it >> has stainless steel wool inside and maybe ceramic mat over that. >> For fun I stuffed ceramic mat into the 4" pipe and it did quite >> things down. Except with the 4" tube being open at both ends, it >> sucked it out. Right now I'm trying to source some high temp ss >> fiber mat to first wrap the pipe, then wrap the ceramic over >> that, then close up both ends. >> >> 1.5minutes into the take off the EGT probe right before the 4" >> pipe is 1700F. ?? (EGT1 = 1768F, EGT2= 1819F) >> >> - Matt Boiteau >>> >>> On 2019-11-11 5:19:37 AM, Le Roux Breytenbach >>> breytenbachleroux@gmail.com >>> >>> wrote: >>> >>> Matt: So the setup for your exhaust, is more or less the one >>> that Paul >>> Lamar suggest in his forum, 2 years or so ago.? >>> The coax muffler ? >>> Le Roux Breytenbach >>> >>> >>> On Mon, Nov 11, 2019 at 5:38 AM Matt Boiteau >>> mattboiteau@gmail.com >>> 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 >>> -- >>> Homepage: http://www.flyrotary.com/ >>> Archive and UnSub: >>> http://mail.lancaironline.net:81/lists/flyrotary/List.html > > --------------2C9F10B185D0EE17B76B34FE Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 7bit
No, it's simply a 2.5" tube welded onto the outlet of the Hushpower "muffler".

If I remember correctly, the innards of the Hushpower muffler were all blown out when I did this. But the key to noise reduction in the cockpit seems to be to get the exhaust pointed away from the cockpit. Granted, probably doesn't do much for people on or near the airport :)

Yes, it may increase drag to have the plume(s) pointed down instead of aft. I didn't try to measure that.

Finn


On 11/11/2019 12:40 PM, Matt Boiteau mattboiteau@gmail.com wrote:
It's behind the rear bulkhead by a ft or so. The perforated store bought sheet is extremely holey, found in typical mufflers. I do have a 4ft 2.5" solid tube I bought just incase i drill my own holes.

Is your exhaust tube inside a surrounding tube? Or you just extended the current exhaust (2.5" or 3"?) 3 ft more, capped off the end of it?

- Matt Boiteau

On Mon, Nov 11, 2019, 11:20 Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:
On?? my RV-3B I added a 3' long pipe with 1/8" holes drilled in the bottom of it (faced down). Tube closed at the end. Area of the 1/8" holes add up to the cross section are of the tube.
That did reduce the noise in the cockpit noticeably.

Is your final exit well behind the cockpit? If so, the sound must be transmitted through the surrounding (outer) pipe.

Finn

On 11/11/2019 10:29 AM, Matt Boiteau mattboiteau@gmail.com wrote:
Yes more or less like the coax muffler. Instead of drilling a few holes here and there, I bought a perforated sheet and welded it into a tube. I wanted to have it open on both ends, to create a vacuum and help suck the air out of the cowl. But right now to make flights enjoyable, I might close up the ends and see how that works.

Is anyone running a coax muffler ? Because it's extremely loud in my case.

I did buy the??Aero Exhaust AT2525XL and it worked great while doing all my ground testing, but the 6" outer shell was just to big to fit under the plane. Sadly I brought it back home to Canada and haven't flown with it yet here in FL. I'll pack it in my suitcase next trip down.

The racing beat presilencer is suppose to be good. I believe it has stainless steel wool inside and maybe ceramic mat over that. For fun I stuffed ceramic mat into the 4" pipe and it did quite things down. Except with the 4" tube being open at both ends, it sucked it out. Right now I'm trying to source some high temp ss fiber mat to first wrap the pipe, then wrap the ceramic over that, then close up both ends.

1.5minutes into the take off the EGT probe right before the 4" pipe is 1700F. ?? (EGT1 = 1768F, EGT2= 1819F)

- Matt Boiteau

On 2019-11-11 5:19:37 AM, Le Roux Breytenbach breytenbachleroux@gmail.com <flyrotary@lancaironline.net> wrote:

Matt: So the setup for your exhaust, is more or less the one that Paul
Lamar suggest in his forum, 2 years or so ago.?
The coax muffler ?
Le Roux Breytenbach


On Mon, Nov 11, 2019 at 5:38 AM Matt Boiteau mattboiteau@gmail.com
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
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html



--------------2C9F10B185D0EE17B76B34FE--