Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Sat, 31 May 2003 22:02:21 -0400 Message-ID: X-Original-Return-Path: Received: from [65.54.168.121] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.1b6) with ESMTP id 2369873 for flyrotary@lancaironline.net; Sat, 31 May 2003 15:12:49 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Sat, 31 May 2003 12:12:48 -0700 Received: from 67.243.12.157 by bay3-dav17.bay3.hotmail.com with DAV; Sat, 31 May 2003 19:12:47 +0000 X-Originating-IP: [67.243.12.157] X-Originating-Email: [lors01@msn.com] Reply-To: "Tracy Crook" From: "Tracy Crook" X-Original-To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EGT's; Fuel consumption X-Original-Date: Sat, 31 May 2003 15:11:20 -0400 Organization: Real World Solutions Inc. MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-Original-Message-ID: X-OriginalArrivalTime: 31 May 2003 19:12:48.0217 (UTC) FILETIME=[9F9A1490:01C327A8] > Posted for "Al Gietzen" : > > > Tracy wrote: > ran well below best power mixture in the > Sun 100 race (16.5 GPH) and stayed ahead of half the 180 HP RVs. > > BTW; Tracy, what EGTs were you showing at that point. What > do you get at best power? > > Al > > EGT during race was around 1650 (LOP). Best > power is around 1750. > > Tracy > > Hum-m-m; based on my results, these EGTs seem a bit on the high side. I > found best power EGTs (WOT) about as follows: 5000 rpm - 1560, 6000 rpm - > 1630. What does it mean? >Al Good question Al, here's my best guess(es). Ignition advance affects EGT more than expected so that could be a factor. Note that EGT continues to fall when advancing the ignition timing past the point of best power but this probably is not the case here. EGT probe placement could also account for some difference. My CR is slightly higher but this causes lower EGT, not higher. Maybe its my tuned intake manifold giving higher effective manifold pressures. EGT does go up at higher manifold pressure, all else being equal. My readings were at WOT near SL. Another factor may be my stinginess with the mixture control. I think you are correct that *absolute best* power is ~ 150 deg F rich of peak. I don't usually push it that far because the power increase past about 50 deg is very small and unless it is a war emergency situation, the increase in power is not worth the additional fuel burn. The figures I gave reflect this. Looking back over my notes I see that 1750 is only about 20 - 25 degrees below peak. Thanks for passing along the other dyno data. It is amazingly close to the figures I calculated. My economy cruise BSFC number was .46 - .47. Tracy