X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.123] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3497914 for flyrotary@lancaironline.net; Tue, 17 Feb 2009 17:46:28 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.123; envelope-from=eanderson@carolina.rr.com Received: from computername ([75.191.186.236]) by cdptpa-omta02.mail.rr.com with ESMTP id <20090217224551.GJYI18810.cdptpa-omta02.mail.rr.com@computername> for ; Tue, 17 Feb 2009 22:45:51 +0000 From: "Ed Anderson" To: "'Rotary motors in aircraft'" Subject: Staging Bog and Lean mixture Date: Tue, 17 Feb 2009 17:45:52 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0063_01C99127.93A5D2C0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: AcmRUXwojSVTnIXFSz29KNCUMmP4Ig== X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Message-Id: <20090217224551.GJYI18810.cdptpa-omta02.mail.rr.com@computername> This is a multi-part message in MIME format. ------=_NextPart_000_0063_01C99127.93A5D2C0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Tracy, for what it's worth, I also see the leaning of the mixture at the staging point which happens to also coincide with the staging "bog". I never knew what was causing the bog and since I don't fly there nor encounter if during flight, it's never really bothered other than wondering about what was causing it. Once I had a screen display to watch the bin pointer, the staging point and the air/fuel mixture on the same screen, all at the same time, it became very clear that leaning of the mixture (or at least that is the indication of air/fuel ratio indicator) is happening. As my bin pointer moves from the hump at the idle (low rpm) region, it jumps from the low rpm map to the high power/manifold pressure chart above bin 64 - not staged yet. Still no bog, but as it moves a few bins higher the air/fuel indicator dives from rich side to off the bottom of the scale lean and the bog begins. At this point my staging sign goes from 2 injectors to 4 injectors indicating that the EC2 has signaled staging. It last for approx 3-5 bins (memory's a bit vague here) before the A/F indicator comes back up the scale. So something is causing a lean condition. I always speculated that it had something to do with the air/fuel mixture in the secondaries making the transition from "dry" to wet - but couldn't quite convince myself. The only way I have been able to eliminate the bog is to increase the richness of that region (3-4 bins) to approx 80-90 (out of 255) which is not really a rich setting, but it works and has eliminated the bog. I enrich each bin's bar watching the A/F indicator as soon as it stops going completely off the lean end of the scale, I stop and that seems to work for me. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW ------=_NextPart_000_0063_01C99127.93A5D2C0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Tracy, for what it’s worth, I also see the leaning of the = mixture at the staging point which happens to also coincide with the staging “bog”.

I never knew what was causing the = bog and since I don’t fly there nor encounter if during flight, it’s = never really bothered other than wondering about what was causing = it.

 

Once I had a screen display to = watch the bin pointer, the staging point and the air/fuel mixture on the same = screen, all at the same time, it became very clear that leaning of the mixture (or = at least that is the indication of air/fuel ratio indicator) is = happening.

 

As my bin pointer moves from the = hump at the idle (low rpm) region, it jumps from the low rpm map to the high power/manifold pressure chart above bin 64 – not staged yet.  = Still no bog, but as it moves a few bins higher   the air/fuel = indicator dives from rich side to off the bottom of the scale lean and the bog = begins. At this point my staging sign goes from 2 injectors to 4 injectors = indicating that the EC2 has signaled staging.  It last for approx 3-5 bins = (memory’s a bit vague here) before the A/F indicator comes back up the = scale.  So something is causing a lean condition.  I always speculated that it = had something to do with the air/fuel mixture in the secondaries making the transition from ”dry” to wet - but couldn’t quite = convince myself. 

 

The only way I have been able to = eliminate the bog is to increase the richness of that region (3-4 bins) to approx = 80-90 (out of 255) which is not really a rich setting, but it works and has = eliminated the bog.  I enrich each bin’s bar watching the A/F indicator = as soon as it stops going completely off the lean end of the scale, I stop and = that seems to work for me.

 

Ed

 

Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews, NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

 

 



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