X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4191462 for flyrotary@lancaironline.net; Thu, 01 Apr 2010 02:32:36 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id E56941738C3 for ; Thu, 1 Apr 2010 14:31:59 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 80055BEC03A for ; Thu, 1 Apr 2010 14:31:59 +0800 (WST) Message-ID: <1A7DA85A241943E69DBC9F764B9608DA@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Tuned lengths Date: Thu, 1 Apr 2010 16:31:59 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001E_01CAD1B8.DA3EB210" 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 X-Antivirus: avast! (VPS 100331-2, 03/31/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_001E_01CAD1B8.DA3EB210 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, Your probably right, but for me, I'm planning a single rotor, a 2 rotor = is way too heavy as it not only affects the weight and balance it puts = me over a certain weight limit. If I were to use a 2 rotor I might not = even worry as 160 hp would be more than adequate - then there's those = who like to squeeze the efficiencies as much as possible, like Ed. Then = there's those who do it because it can be done. I also find it = interesting research. George (down under) 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 ------=_NextPart_000_001E_01CAD1B8.DA3EB210 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Al,

Your probably right, but for me, I'm planning a single rotor, a 2 rotor is way too heavy = as it not=20 only affects the weight and balance it puts me over a certain = weight=20 limit. If I were to use a 2 rotor I might not even worry as 160 hp would = be more=20 than adequate - then there's those who like to squeeze the efficiencies = as much=20 as possible, like Ed. Then there's those who do it because it can be = done. I=20 also find it interesting research.

George (down under)

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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