Return-Path: Received: from fed1rmmtao08.cox.net ([68.230.241.31] verified) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP id 3227892 for flyrotary@lancaironline.net; Wed, 12 May 2004 01:43:05 -0400 Received: from BigAl ([68.107.116.221]) by fed1rmmtao08.cox.net (InterMail vM.6.01.03.02 201-2131-111-104-20040324) with ESMTP id <20040512054258.DUDL3867.fed1rmmtao08.cox.net@BigAl> for ; Wed, 12 May 2004 01:42:58 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Runner Length Date: Tue, 11 May 2004 22:43:10 -0700 Message-ID: <000001c437e4$027a7ef0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C437A9.561BA6F0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C437A9.561BA6F0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Al, focusing on the losses at these velocities and thinking that re-accelerating the column of air in the intake tract is a bad thing misses the point entirely. That's like saying a supercharger will drop horsepower because it takes power from the engine to turn it. Well; I don't think it misses the point entirely. I was just pointing out that accelerating the air uses energy, which is a negative in addition to other losses (reducing manifold pressure). I didn't mean to imply that you couldn't get it back in a greater charge - it's just not free. And, of course we must keep in mind that inertial effect is separate from the harmonic effect. Here is a link to a pretty good explanation of how to select the correct intake runner length: http://www.hotrod.com/projectbuild/113_9907_efi/ They say that the runner length should equal the third harmonic wavelength. Al >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_0001_01C437A9.561BA6F0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Al, focusing on the losses = at these velocities and thinking that re-accelerating the column of air in the = intake tract is a bad thing misses the point entirely. That's like saying = a supercharger will drop horsepower because it takes power from the engine to turn = it.

Well; I don’t think it = misses the point entirely. I = was just pointing out that accelerating the air uses energy, which is a negative = in addition to other losses (reducing manifold pressure). I = didn’t mean to imply that you couldn’t get it back in a greater charge = – it’s just not free.

And, of course we must keep = in mind that inertial effect is separate from the harmonic = effect.

       &nbs= p;Here is a link to a pretty good explanation of how to select the correct = intake runner length:

        http://www.hotrod.com/projectbuild/113_9907_efi/=

        They say = that the runner length should equal the third harmonic wavelength.
Al

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