X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5545584 for flyrotary@lancaironline.net; Wed, 16 May 2012 13:24:02 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=2.0 cv=eq5dP/VX c=1 sm=0 a=g3L/TDsr+eNLfIieSKfGkw==:17 a=AHkS0RJitIMA:10 a=FCMO-upCwesA:10 a=05ChyHeVI94A:10 a=8nJEP1OIZ-IA:10 a=arxwEM4EAAAA:8 a=r1ClD_H3AAAA:8 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=HZJGGiqLAAAA:8 a=7g1VtSJxAAAA:8 a=0JbonnflDeLc4U_FZPIA:9 a=jSKLB59JvZKXfyfMu3MA:7 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=HeoGohOdMD0A:10 a=g3L/TDsr+eNLfIieSKfGkw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.170.10 Received: from [174.110.170.10] ([174.110.170.10:57744] helo=EdPC) by cdptpa-oedge02.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 1E/75-05935-F82E3BF4; Wed, 16 May 2012 17:23:27 +0000 Message-ID: <241108991CBA428C9667B260F501FCAF@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Why Apha N?? : [FlyRotary] Re: With great power comes...the ability to muck things up Date: Wed, 16 May 2012 13:23:27 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 Good to hear you are back in business, Ernest I do have one question - why did you switch from Speed Density to Alpha N. For sea level applications high power operations I can sort of see using Alpha N - but for aircraft application I would have assumed Speed Density would be a better choice. Would be interested in why you went with Alpha N Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com -------------------------------------------------- From: "Mark Steitle" Sent: Wednesday, May 16, 2012 12:56 PM To: "Rotary motors in aircraft" Subject: [FlyRotary] Re: With great power comes...the ability to muck things up > Ernest, > > Great diagnostics there. Let us know how the MegaSquirt works out. > > Mark > > On 5/16/12, Ernest Christley wrote: >> I cleaned the plugs, but they just kept getting flooded, and despite the >> modifications I made to the intake manifold, I >> was still getting fuel pooled in there. >> >> I moved on to checking the spark. The timing light was only flashing >> occasionally, and I noticed that my VR sensor was >> mounted so that it was almost in front of the toothed wheel. I have some >> new tools I didn't have when I originally cast >> the mount, so I cleaned it up, and trued it. Timing light was still >> sporadic. Plugged the wire into a scrap spark plug >> and sat it on the engine while I cranked. Nice, consistent blue-white >> spark. May have been there all along, but at >> least my VR sensor mount looks nicer. >> >> I've got new fuel, good compression, and good spark. Deep breath, back >> up, >> and compare what I have now to what I had >> when it was running back in November. I consult TunerStudio (the user >> interface I'm using to my engine controller). >> The only thing significantly different is that I converted from using >> Speed-Density to Alpha-N. >> >> Background: MegaSquirt has several, user-configurable ways to determine >> how >> long to have the fuel injectors spray. One >> way is to measure the manifold pressure and combine that with the RPM. >> Another is to look at where the throttle is and >> combine that with RPM. Both are just secondary measurements of how much >> air >> the engine is swallowing, and have a whole >> slew of corrections and modifications for various conditions. Tuning >> involves filling numbers into a table. Across the >> bottom is the RPM. Up the side is either the throttle position, or the >> manifold pressure. For each cell you specify a >> volumetric efficiency as a percentage. You've already specified how long >> the injectors would spray for a 100% VE cycle, >> so the cells essentially become a percentage of that value. By switching >> modes, my table no longer resembled reality. >> Instead of picking up the value of 43 from the table while cranking, it >> was >> picking up a different cell that had 93. >> More than double the required fuel. >> >> I switched the setting back, and gave it a try this morning. It took >> about >> 30 seconds of spinning while it was >> obviously trying to kick off before it caught up and ran smooth at 1500 >> RPM. >> It has taken two weeks since I got >> everything painted and tried start taxi testing, but I'm now back in the >> game. >> >> -- >> Homepage: http://www.flyrotary.com/ >> Archive and UnSub: >> http://mail.lancaironline.net:81/lists/flyrotary/List.html >> > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html