X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 23 Sep 2005 22:26:05 -0400 Message-ID: X-Original-Return-Path: Received: from smtpauth06.mail.atl.earthlink.net ([209.86.89.66] verified) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 731530 for lml@lancaironline.net; Fri, 23 Sep 2005 21:17:39 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.66; envelope-from=lancair403@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=pphx5n0inR2OjBxmrVwBJLM3hpylLbuUXNBn6wZK3gZIgBNlrhegE3sDtR2M35SA; h=Received:Message-ID:X-Priority:Reply-To:X-Mailer:From:To:Subject:Date:MIME-Version:Content-Type:X-ELNK-Trace:X-Originating-IP; Received: from [4.153.188.129] (helo=earthlink.net) by smtpauth06.mail.atl.earthlink.net with asmtp (Exim 4.34) id 1EIyer-0002MB-DV for lml@lancaironline.net; Fri, 23 Sep 2005 21:16:54 -0400 X-Original-Message-ID: <410-22005962411646625@earthlink.net> X-Priority: 3 Reply-To: lancair403@earthlink.net X-Mailer: EarthLink MailBox 2005.1.47.0 (Windows) From: "william rumburg" X-Original-To: "Lancair Mailing List" Subject: Engine Cooling and Cabin Heat X-Original-Date: Fri, 23 Sep 2005 21:16:46 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_84815C5ABAF209EF376268C8" X-ELNK-Trace: 27715828ce90b1c1624ea3431430cac6239a348a220c2609e269b36dbcfd69078740c7db72c3a6ff350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 4.153.188.129 ------=_NextPart_84815C5ABAF209EF376268C8 Content-type: text/plain; charset=US-ASCII Engine cooling air inlets on my 320 cowl measured about 3-3/4 inches circular as the molded parts were received. I'm certain they were designed to be four inches and, even at that, are marginal in order to minimize cooling drag. I enlarged them to the four inch dimension and believe it to be a smart move. CHTs for my IO-320 are about 400 on climb out and 360 to 380 in cruise (dependent on altitude and power setting) which isn't bad, but I'd like to see them a little lower. My only intentional drain of engine cooling air was a 1/2 inch tube to cool the gascolator and electric boost pump; however, when the cabin heat valve was recently discussed, I realized that valve supplied by Lancair exhausts air overboard when closed and is thus a useless drain of cooling air - if it's source is a 1-1/2 opening in the baffling. Am I correct and would installing a seperate NACA duct to supply air to the cabin heat valve result in lower CHTs? Bill Rumburg N403WR (Sonic bOOm) ------=_NextPart_84815C5ABAF209EF376268C8 Content-Type: text/html; charset=US-ASCII
Engine cooling air inlets on my 320 cowl measured about 3-3/4 inches circular as the molded parts were received. I'm certain they were designed to be four inches and, even at that, are marginal in order to minimize cooling drag. I enlarged them to the four inch dimension and believe it to be a smart move. CHTs for my IO-320 are about 400 on climb out and 360 to 380 in cruise (dependent on altitude and power setting) which isn't bad, but I'd like to see them a little lower.
My only intentional drain of engine cooling air was a 1/2 inch tube to cool the gascolator and electric boost pump; however, when the cabin heat valve was recently discussed, I realized that valve supplied by Lancair exhausts air overboard when closed and is thus a useless drain of cooling air - if it's source is a 1-1/2 opening in the baffling.
Am I correct and would installing a seperate NACA duct to supply air to the cabin heat valve result in lower CHTs?
 
Bill Rumburg
N403WR (Sonic bOOm)
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