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 5.4c3j) with ESMTP id 4986138 for flyrotary@lancaironline.net; Tue, 17 May 2011 07:23:02 -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=1.1 cv=2lq4+qobG88tJFkiXmxSLStFAwyj+PriBwHB+7DDebs= c=1 sm=0 a=vr0ONXUfNoUA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=7g1VtSJxAAAA:8 a=Ia-xEzejAAAA:8 a=eGw9Y_tG5q9TwnINev4A:9 a=9cqYel2rpq4tbDvpMW0A:7 a=wPNLvfGTeEIA:10 a=Qa1je4BO31QA:10 a=ayC55rCoAAAA:8 a=MLIjaRJELZrGAgEnDn0A:9 a=tS93685JEXvb6U0IjXgA:7 a=EzXvWhQp4_cA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:59665] helo=EdPC) by cdptpa-oedge01.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 6B/62-17273-27A52DD4; Tue, 17 May 2011 11:22:26 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Reliably starting Date: Tue, 17 May 2011 07:22:21 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0034_01CC1463.299C03B0" 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 This is a multi-part message in MIME format. ------=_NextPart_000_0034_01CC1463.299C03B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Ernest, Not that familiar with the Microsquirt system. But, If I am = interpreting parts of your graph (your Air/Fuel Ratio), it looks to me = that yes, the Fuel dramatically increases right after start to around = 10:1, but then it drops off to around 22:1 - a very lean mixture as you = pull the throttle back. =20 My experience has been that at idle the air/fuel ratio required is = higher than cruise. Supposedly the ratio of accessories (water pump, = alternator, oil pump etc) are a higher proportion of the small amount of = power being produced at idle - therefore a higher air/fuel ratio is = required to get the most power out of the relative small amount of air = going through the engine at idle. As you know, you can have a 12.5:1 = air/fuel ratio at any rpm/ manifold pressure - its just the absolute = amount of fuel at that ratio is much lower at idle than WOT. . The MAP appears to correlate with the fuel ratio, in that when the = MAP is WOT (I presume that is around 46.4 Min (min pressure =3D max = vac?) then the airfuel ratio is at its highest (near 9:1). While that = is a bit rich in my opinion even for WOT (best power is around 12.5:1), = I don't find it unreasonable for starting out your tuning process. The A/F ratio is jumping around but it appears to be in sync with your = MAP also jumping around - so no surprise to me since the two are sort of = wedded. So the 10:1 ratio is either a large increase in fuel at that point - OR = a considerable reduction in air density at that point. Either will can = give you the 10:1 ratio. Get your oil leak fixed and give us some more data Ed From: Ernest Christley=20 Sent: Monday, May 16, 2011 11:21 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Reliably starting I adjusted the VE tables, and my engine started and ran MUCH smoother = than yesterday. This graph shows the result of several starts this = evening. It is just a couple of blades and the engine is off to the = races. Problem is that the AFR drops to as low as 10, then jumps all = over the place. Looking at the tuning parameters, my cranking = pulsewidth for the injectors is WAY to high, and then I have no after = start enrichment. I would update those and go run some more, but I've developed an oil = leak on the propeller side of my PSRU, and I think my blower has come = apart. I've got to tear down the front of the engine and figure out = what's going on. I might also have a leak between the bed-type mount = plate and engine. I'm not even wanting to think about that one right = now. ...building and airplane =3D> put it together. Pull it apart. Put it = together. Pull it apart...... -------------------------------------------------------------------------= ------- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0034_01CC1463.299C03B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Ernest,
 
Not that familiar with the Microsquirt = system.  But,=20 If I am interpreting parts of your graph (your Air/Fuel Ratio), it looks = to me=20 that yes, the Fuel dramatically increases right after start to around = 10:1, but=20 then it drops off to around 22:1 - a very lean mixture as you pull the = throttle=20 back. 
 
My experience has been that at idle the air/fuel = ratio=20 required is higher than cruise.  Supposedly the ratio of = accessories (water=20 pump, alternator, oil pump etc) are a higher proportion of = the small amount=20 of power being produced at idle - therefore a higher air/fuel ratio is = required=20 to get the most power out of the relative small amount of air going = through=20 the engine at idle.   As you know, you can have a = 12.5:1=20 air/fuel ratio at any rpm/ manifold pressure - its just the absolute = amount of=20 fuel at that ratio is much lower at idle than WOT.
 
.  The MAP appears to correlate with the = fuel ratio,=20 in that when the MAP is WOT (I presume that is around 46.4 Min (min = pressure =3D=20 max vac?) then the airfuel ratio is at its highest (near 9:1).  = While that=20 is a bit rich in my opinion even for WOT (best power is around 12.5:1), = I don't=20 find it unreasonable for starting out your tuning process.
 
The A/F ratio is = jumping around=20 but it appears to be in sync with your MAP also jumping around - so no = surprise=20 to me since the two are sort of wedded.
 
So the 10:1 ratio is either a large increase in = fuel at=20 that point - OR a considerable reduction in air density at that = point. =20 Either will can give you the 10:1 ratio.
 
Get your oil leak fixed and give us some more=20 data
 
Ed
 

Sent: Monday, May 16, 2011 11:21 PM
Subject: [FlyRotary] Reliably starting

I adjusted the VE tables, and my engine = started and=20 ran MUCH smoother than yesterday.  This graph shows the result of = several=20 starts this evening.  It is just a couple of blades and the engine = is off=20 to the races.  Problem is that the AFR drops to as low as 10, then = jumps=20 all over the place.  Looking at the tuning parameters, my cranking=20 pulsewidth for the injectors is WAY to high, and then I have no after = start=20 enrichment.

I would update those and go run some more, but I've = developed=20 an oil leak on the propeller side of my PSRU, and I think my blower has = come=20 apart.  I've got to tear down the front of the engine and figure = out what's=20 going on.  I might also have a leak between the bed-type mount = plate and=20 engine.  I'm not even wanting to think about that one right=20 now.

...building and airplane  =3D> put it = together.  Pull it=20 apart.  Put it together.   Pull it apart......

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