X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf24aec.mail.bellsouth.net ([205.152.59.72] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with ESMTP id 1100157 for flyrotary@lancaironline.net; Wed, 10 May 2006 22:58:51 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.72; envelope-from=sladerj@bellsouth.net Received: from ibm68aec.bellsouth.net ([65.2.91.23]) by imf24aec.mail.bellsouth.net with ESMTP id <20060511025807.JOLK13458.imf24aec.mail.bellsouth.net@ibm68aec.bellsouth.net> for ; Wed, 10 May 2006 22:58:07 -0400 Received: from [192.168.1.97] (really [65.2.91.23]) by ibm68aec.bellsouth.net with ESMTP id <20060511025807.HWAR10163.ibm68aec.bellsouth.net@[192.168.1.97]> for ; Wed, 10 May 2006 22:58:07 -0400 Message-ID: <4462A835.2060904@bellsouth.net> Date: Wed, 10 May 2006 22:57:57 -0400 From: John Slade User-Agent: Thunderbird 1.5.0.2 (Windows/20060308) MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Pusher cooling References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit > they are used in the augmentor tube to suck and expel the hot air from under the cowling. I think Buly's right. Exhaust augmentation has a big effect on ground cooling. I have the exhaust letting out into a 6 inch stainless tube which exits the cowl at the rear. The exhaust pipe stops about 2 inches short of the end of the tube. All the air expelled has to come through the NACA, into a plenum, then through the coolers. I had a fan installed, but it didn't any measurable difference (probably because it was just circulating air) so I removed it. Without the fan my engine stabilizes at about 195F during prolonged taxiing on a 90F day. As long as I save any significant use of power until the run-up right before take-off, I can taxi for as long as I have fuel. John