Return-Path: Received: from fed1rmmtao04.cox.net ([68.230.241.35] verified) by logan.com (CommuniGate Pro SMTP 4.2.1) with ESMTP id 410693 for flyrotary@lancaironline.net; Tue, 14 Sep 2004 14:48:47 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.35; envelope-from=ALVentures@cox.net Received: from BigAl ([68.107.116.221]) by fed1rmmtao04.cox.net (InterMail vM.6.01.03.04 201-2131-111-106-20040729) with ESMTP id <20040914184516.JRIG13013.fed1rmmtao04.cox.net@BigAl> for ; Tue, 14 Sep 2004 14:45:16 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: NACA vs. P51 Scoop Date: Tue, 14 Sep 2004 11:45:35 -0700 Message-ID: <000001c49a8b$05756d90$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C49A50.59169590" 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 V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C49A50.59169590 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I'd say forget the intermittent firing mode. For the same power it = would likely result in just as much,+ or - , as reduced throttle; and shake = the hell out of everything connected to the engine. As I understand it, the Cadillac mode is an attempt to improve mileage at low load; maybe 15 - = 20% power or less. =20 If you are going to try to design against coolant loss; you may just as = well try to design against loss of oil, about the same probability of = occurrence. =20 As far as scoops are concerned, a NACA scoop may work fine if everything else is right, but will never have the pressure recovery efficiency of a well designed ram scoop. =20 That'll be 2 cents, please :-) =20 Al ------=_NextPart_000_0001_01C49A50.59169590 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

I'd say forget the intermittent firing mode. = For the same power it would likely result in just as much,+ or - , as reduced = throttle; and shake the hell out of everything connected to the engine. As I understand it, the Cadillac mode is an attempt to improve mileage at low = load; maybe 15 - 20% power or less.

If you are going to try to design against coolant = loss; you may just as well try to design against loss of oil, about the same probability of occurrence.

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As far as = scoops are concerned, a NACA scoop may work fine if everything else is right, but = will never have the pressure recovery efficiency of a well designed ram = scoop.

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That'll be 2 = cents, please J

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