X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao102.cox.net ([68.230.241.44] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4191392 for flyrotary@lancaironline.net; Wed, 31 Mar 2010 23:46:49 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.44; envelope-from=alventures@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao102.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100401034615.OQXY20234.fed1rmmtao102.cox.net@fed1rmimpo01.cox.net> for ; Wed, 31 Mar 2010 23:46:15 -0400 Received: from BigAl ([72.192.128.205]) by fed1rmimpo01.cox.net with bizsmtp id 03mE1e00A4S1t5C033mEQE; Wed, 31 Mar 2010 23:46:14 -0400 X-VR-Score: 0.00 X-Authority-Analysis: v=1.1 cv=3rYd4LfcKLU522ZHXfO06E856SAcXud2pffNCWjpFlA= c=1 sm=1 a=Vegc0WxVmH5BHtpNDyThtA==:17 a=MrUB0Umc2BtLC2n3NIoA:9 a=1WBGJRmdEkJfk9hY1PcuEsEeZNQA:4 a=CjuIK1q_8ugA:10 a=Z34ij6bae8jLSqLSyC0A:9 a=MYIqmvbzOyxoDpK1PmsA:7 a=J4ZEcfMK-dLimMHP63v7WYnHXP4A:4 a=Vegc0WxVmH5BHtpNDyThtA==:117 X-CM-Score: 0.00 From: "Al Gietzen" To: "Rotary motors in aircraft" Subject: Tuned lengths Date: Wed, 31 Mar 2010 20:46:16 -0800 Message-ID: <26BAB5998ECA4EF0AAD30C1C7FA0C45E@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01CAD113.3573B640" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6856 Importance: Normal Thread-Index: AcrRVkNWAV3ps037RdS5bcRgKNhfQg== X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0006_01CAD113.3573B640 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable So let me just play devils advocate and throw this in here. =20 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. =20 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. =20 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. =20 Just a thought, =20 Al G =20 =20 ------=_NextPart_000_0006_01CAD113.3573B640 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

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

 

 

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