X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from relais.videotron.ca ([24.201.245.36] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4192101 for flyrotary@lancaironline.net; Thu, 01 Apr 2010 12:34:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.201.245.36; envelope-from=geryvon@videotron.ca MIME-version: 1.0 Content-type: multipart/alternative; boundary="Boundary_(ID_ZG3wIt266EQ9xSRvdTTDoQ)" Received: from nspaa334e891d2 ([66.130.84.106]) by VL-MO-MR004.ip.videotron.ca (Sun Java(tm) System Messaging Server 6.3-8.01 (built Dec 16 2008; 32bit)) with SMTP id <0L0700755I0RL350@VL-MO-MR004.ip.videotron.ca> for flyrotary@lancaironline.net; Thu, 01 Apr 2010 12:34:03 -0400 (EDT) Message-id: From: Yvon Cournoyer To: Rotary motors in aircraft References: Subject: Re: [FlyRotary] Tuned lengths Date: Thu, 01 Apr 2010 12:33:53 -0400 X-Priority: 3 X-MSMail-priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. --Boundary_(ID_ZG3wIt266EQ9xSRvdTTDoQ) Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7BIT Please post drawings/photos/specs...Yvon ----- Original Message ----- From: Al Gietzen To: Rotary motors in aircraft Sent: Thursday, April 01, 2010 12:46 AM Subject: [FlyRotary] Tuned lengths So let me just play devils advocate and throw this in here. I designed my intake manifold to be compact, lightweight, and fit into the cowl without any contusions or bumps. I designed a compact tangential muffler, and a secondary muffler, for light weight and suppression of the noise. No effort to 'tune' on either end. The result is that I get a very flat torque curve, and about 90 HP per rotor at 6300, using the 9.7 turbo rotors in a NA engine (actual dyno data). It is also one of the quietest rotarys around and the exhaust system is still solid and sound after 180 hrs of operation. No; I'm not bragging - and I don't doubt that a few more HP could be squeezed out over a small rpm range with tuning. The point is simply - how much time and effort do you want to put into the misty netherland of tuning the intake and exhaust? Maybe focus on lightweight and durable design. Just a thought, Al G --Boundary_(ID_ZG3wIt266EQ9xSRvdTTDoQ) Content-type: text/html; charset=iso-8859-1 Content-transfer-encoding: quoted-printable
Please post=20 drawings/photos/specs...Yvon
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Thursday, April 01, 2010 = 12:46=20 AM
Subject: [FlyRotary] Tuned = lengths

So let me just play = devils=20 advocate and throw this in here.

 

I designed my intake = manifold to=20 be compact, lightweight, and fit into the cowl without any contusions = or=20 bumps. I designed a compact tangential muffler, and a secondary = muffler, for=20 light weight and suppression of the noise. No effort to =91tune=92 on = either=20 end.

 

The result is that I = get a very=20 flat torque curve, and about 90 HP per rotor at 6300, using the 9.7 = turbo=20 rotors in a NA engine (actual dyno data).  It is also one of the = quietest=20 rotarys around and the exhaust system is still solid and sound after = 180 hrs=20 of operation.

 

No; I=92m not bragging = =96 and I=20 don=92t doubt that a few more HP could be squeezed out over a small = rpm range=20 with tuning. The point is simply =96 how much time and effort do you = want to put=20 into the misty netherland of tuning the intake and exhaust?  = Maybe focus=20 on lightweight and durable design.

 

Just a=20 thought,

 

Al G

 

 

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