X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao105.cox.net ([68.230.241.41] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3636782 for flyrotary@lancaironline.net; Sat, 09 May 2009 00:08:16 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.41; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao105.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090509040739.MIKM20430.fed1rmmtao105.cox.net@fed1rmimpo01.cox.net> for ; Sat, 9 May 2009 00:07:39 -0400 Received: from wills ([68.105.85.56]) by fed1rmimpo01.cox.net with bizsmtp id pG7c1b0051CvZmk03G7e42; Sat, 09 May 2009 00:07:38 -0400 X-Authority-Analysis: v=1.0 c=1 a=KBukooACTyUA:10 a=tmOIriySRmwA:10 a=JYUj9TRVASMAwpTlKLoA:9 a=1jcqqn5r2SVkZGw6D7gA:7 a=RdqZHYXXSccnCQ3FXQQ9Iwoo3_QA:4 a=zqXRXsriYoUA:10 a=K16AMHFJR71oxWW0:21 a=0_aMYMeLjQQ8KSzJ:21 a=B59BV3jAAAAA:8 a=Ia-xEzejAAAA:8 a=IXM4oLkqScK7JGF5RzQA:9 a=EMTiePFGRFGAiUH2rJQA:7 a=xGJpZcvNKLT2dzruvNns_V0cQgQA:4 a=xt8YVOILpfUA:10 a=EzXvWhQp4_cA:10 X-CM-Score: 0.00 Message-ID: <7E6111AEE651419783C17AFFD1413B64@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Initial Tuning at Low RPM - surging? Date: Fri, 8 May 2009 21:07:34 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003D_01C9D021.025346C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_003D_01C9D021.025346C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Mike, In the early tuning of my EC2 I had issues with surging at a number of = throttle settings, all low power settings. Higher power settings didnt = show this problem. Problem turned out to be that adjacent addresses in = the EC2 MCT had significantly different values stored. If you have 2 = adjacent addresses where one is significantly leaner (or richer) than = the other then surging is the result. Think about it. Your throttle setting arbitrarily ends up on an MCT = address that is too rich (as an example). As a result the engine bogs a = little and RPM and MAP drop a little - just enough to fall into the next = lower MCT, which is set closer to a correct value. Engine RPM and MAP = pick up a little and push you back up into the next MCT location. Again, = too rich, engine bogs, etc.... I suspected that this was happening but did not know for certain = because I didnt have anyway to see what was actually loaded in the MCT. = When I bought my EC2 and built my panel Tracy's engine monitor didnt = exist. By the time the EM came out I didnt have any way to retrofit it = into my panel - it wouldnt fit. I ended up buying an EFISM from Ed = Anderson. Once I could see what was loaded it was pretty easy to smooth = the MCT and this cured all of my engine roughness and surging. It also = allowed a much lower idle RPM without any gearbox chatter. I cant imagine how you could properly tune the EC2 without having = either the auto tune function or some way to display the MCT. For my = installation the EFISM is an invaluable tool. I would say the same thing = about Tracy's monitor but in my case it was much easier to fit the EFISM = after the fact. I'm sure there could be other things that could cause the surging, but = in my case, this was the problem. I could have saved myself a lot of = hassle had I installed the EFISM sooner. Mike Wills RV-4 N144MW ----- Original Message -----=20 From: Mike Fontenot=20 To: Rotary motors in aircraft=20 Sent: Friday, May 08, 2009 6:44 PM Subject: [FlyRotary] Initial Tuning at Low RPM - surging? I started up the engine tonight, just to be sure it really worked last = Tuesday. Started just fine but there was a=20 kind of surging of the engine at the lowest RPM. If I increased RPM it = started to smooth out. Also increasing the mixture helped a little, but not a lot. My question is: is this surging at low RPM indicative of something = specific (too lean/rich mixture, injectors not putting out too little/much). Something like that? I am just trying = to get a feel for any general rule when running in that manner. And if there is no consistency, that's good to know as well. Thanks, --=20 Mike = =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D Mike Fontenot Apex Consulting & Services LLC Lakewood, Colorado 303 / 731-6645 mikef AT apexconsultingservices DOT com = =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D ------=_NextPart_000_003D_01C9D021.025346C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Mike,
 
 In the early tuning = of my EC2 I had=20 issues with surging at a number of throttle settings, all low power = settings.=20 Higher power settings didnt show this problem. Problem turned out to be = that=20 adjacent addresses in the EC2 MCT had significantly different values = stored. If=20 you have 2 adjacent addresses where one is significantly leaner (or = richer) than=20 the other then surging is the result.
 
 Think about it. Your throttle = setting=20 arbitrarily ends up on an MCT address that is too rich (as an example). = As a=20 result the engine bogs a little and RPM and MAP drop a little - = just enough=20 to fall into the next lower MCT, which is set closer to a correct value. = Engine=20 RPM and MAP pick up a little and push you back up into the next MCT = location. Again, too rich, engine bogs, etc....
 
 I suspected that this was = happening but did=20 not know for certain because I didnt have anyway to see what was = actually loaded=20 in the MCT. When I bought my EC2 and built my = panel Tracy's engine=20 monitor didnt exist. By the time the EM came out I didnt have any way to = retrofit it into my panel - it wouldnt fit. I ended up buying an EFISM = from Ed=20 Anderson. Once I could see what was loaded it was pretty easy to smooth = the MCT=20 and this cured all of my engine roughness and surging. It also allowed a = much=20 lower idle RPM without any gearbox chatter.
 
 I cant imagine how you could = properly tune=20 the EC2 without having either the auto tune function or some way to = display=20 the MCT. For my installation the EFISM is an invaluable tool. I = would say=20 the same thing about Tracy's monitor but in my case it was much easier = to fit=20 the EFISM after the fact.
 
 I'm sure there could be other = things that=20 could cause the surging, but in my case, this was the problem. I could=20 have saved myself a lot of hassle had I installed the EFISM=20 sooner.
 
Mike Wills
RV-4 N144MW
 
----- Original Message -----
From:=20 Mike Fontenot =
Sent: Friday, May 08, 2009 6:44 = PM
Subject: [FlyRotary] Initial = Tuning at=20 Low RPM - surging?

I started up the engine tonight, just to be sure it = really=20 worked last Tuesday. Started just fine but there was a
kind of = surging of=20 the engine at the lowest RPM. If I increased RPM it started to smooth = out.=20 Also increasing the mixture
helped a little, but not a = lot.

My=20 question is: is this surging at low RPM indicative of something = specific (too=20 lean/rich mixture, injectors not
putting out too = little/much). =20 Something like that?  I am just trying to get a feel for any = general rule=20 when running in that
manner.  And if there is no consistency, = that's=20 good to know as well.

Thanks,

--=20 =
Mike

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Mike Fontenot
Apex=20 Consulting & Services LLC
Lakewood, Colorado
303 / = 731-6645
mikef=20 AT apexconsultingservices DOT=20 com
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
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