X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 50 [XX] Return-Path: Sender: To: lml Date: Sun, 03 Dec 2006 10:07:21 -0500 Message-ID: X-Original-Return-Path: Received: from secure5.liveoakhosting.com ([64.49.254.21] verified) by logan.com (CommuniGate Pro SMTP 5.1.3) with ESMTPS id 1634392 for lml@lancaironline.net; Sun, 03 Dec 2006 09:24:16 -0500 Received-SPF: none receiver=logan.com; client-ip=64.49.254.21; envelope-from=walter@advancedpilot.com Received: (qmail 5952 invoked from network); 3 Dec 2006 08:23:54 -0600 Received: from ip12-197-246-235.networkusa.com (HELO ?192.168.1.43?) (12.197.246.235) by rs5.liveoakhosting.com with (AES128-SHA encrypted) SMTP; 3 Dec 2006 08:23:54 -0600 Mime-Version: 1.0 (Apple Message framework v752.3) In-Reply-To: References: Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed X-Original-Message-Id: <30A7A42B-0F0B-4CD2-84F1-A51E1F3ACE30@advancedpilot.com> Content-Transfer-Encoding: 7bit From: Walter Atkinson Subject: Re: [LML] FW: [LML] Re: New (2006) TSIO550E Lean of Peak (LOP) Operation X-Original-Date: Sun, 3 Dec 2006 08:24:21 -0600 X-Original-To: "Lancair Mailing List" X-Mailer: Apple Mail (2.752.3) Well, first of all, we prefer to use 5.85 as the actual weight of avgas. The actual BSFC(min) on the IO-550N is about .385. Walter On Dec 2, 2006, at 9:51 PM, Fred Moreno wrote: Posted for Walter Atkinson : The HP multiplier for LOP is based on the BSFC(min). In the engines with 8.5:1 CR it is 14.9. In the 7.5:1 engines it is about 13.7. Walter ________________________________________________________ Assuming avgas is 6 pounds per gallon, then one can compute the brake specific fuel consumption as follows: 7.5 compression, 6/13.7 = 0.438 pounds/hp hour 8.5 compression, 6/14.9 = 0.403 pounds/hp hr From this we might extrapolate for those IO-550N's engines with 10 compression (recognizing the benefits of compression increases diminish as compression increases) that 10 compression = 0.37 lbs/hp hr (implying that you would use a figure of 16.1 All of this is conditioned on lean of peak operation, all the fuel being burned. If you go into the Columbia 350 operating manual (available on line) and work through the power tables, for 50F LOP operation below 65%, the implied SFC is 0.38-0.39 instead of 0.40 (above). That is probably wishful thinking given the nature of Continental stock fuel injectors. What think you, Walter? Fred Moreno -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.409 / Virus Database: 268.15.5/564 - Release Date: 2/12/2006 -- For archives and unsub http://mail.lancaironline.net/lists/lml/