X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 30 [X] Return-Path: Received: from relais.videotron.ca ([24.201.245.36] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2399086 for flyrotary@lancaironline.net; Sun, 21 Oct 2007 17:07:26 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.201.245.36; envelope-from=geryvon@videotron.ca MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; format=flowed; charset=iso-8859-1; reply-type=original Received: from AMDSEMPRON2400 ([66.130.108.152]) by VL-MO-MR002.ip.videotron.ca (Sun Java(tm) System Messaging Server 6.3-0.15 (built Feb 9 2007)) with SMTP id <0JQA00A1Y5BELRE0@VL-MO-MR002.ip.videotron.ca> for flyrotary@lancaironline.net; Sun, 21 Oct 2007 17:06:50 -0400 (EDT) Message-id: <000d01c81426$4b5ae520$6400a8c0@AMDSEMPRON2400> Reply-to: Yvon Cournoyer From: Yvon Cournoyer To: Marius Negulescu , Alain Cournoyer , Rotary motors in aircraft Subject: ATMOSPHERIC PRESSURE & ENGINE HORSEPOWER AT GROUND LEVEL Date: Sun, 21 Oct 2007 17:05:33 -0400 X-Priority: 3 X-MSMail-priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 Ed Anderson and others have mentionned at times that they observed power output variations at ground level and attributed the variations to variances in atmospheric pressures at ground level. Over the last few days, our area was subjected to very high atm press (approx. 30.5 in. hg.) followed by very low atm press. (approx. 29.4 in. hg.) At full power static runup, I noted 200 rpm less at low pressure. I regret that I did not note the temperature and relative humidity. Max rpm noted 5000. Sorel Airport elevation is 76 ft. Yvon. ~