X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from web83910.mail.sp1.yahoo.com ([69.147.92.115] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with SMTP id 3639698 for flyrotary@lancaironline.net; Tue, 12 May 2009 10:07:59 -0400 Received-SPF: none receiver=logan.com; client-ip=69.147.92.115; envelope-from=delta11xd@att.net Received: (qmail 3279 invoked by uid 60001); 12 May 2009 14:07:22 -0000 Message-ID: <746559.2316.qm@web83910.mail.sp1.yahoo.com> X-YMail-OSG: W7nhYvQVM1kRWxikK6NnrxXBdjSk9LAn2o9HW9ObaE4ZnflUXQywjxT0A4tsFmXHXbERbmIhPYrP09xn_9aR6cRe7MQaS68bvRWdlh_XVZKFlYLSQXs4P1.Lusn0bRhNsKG8sBcXlBIhbJB07pLY_jNg7na1jNM8oQttyD8jxTKr4WvlrnxxMk4_8JaThcneSHHHE1COnwNI2dwSFWWk122Q6b_YS6EU.g_gx72iL4AO0j.n0e4Zj78YxeUXuNsC5NN89wXYflqTwCHPnp_MPF8rp5IteupkNjgh4TX2N1IoOm18dAo.PyZmuBU2kW9eKg-- Received: from [76.243.125.186] by web83910.mail.sp1.yahoo.com via HTTP; Tue, 12 May 2009 07:07:22 PDT X-Mailer: YahooMailWebService/0.7.289.1 Date: Tue, 12 May 2009 07:07:22 -0700 (PDT) From: James Maher Reply-To: delta11xd@att.net Subject: Re: [FlyRotary] Re: Initial Tuning - Today To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1232636239-1242137242=:2316" --0-1232636239-1242137242=:2316 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Mike, Are you using the right fuel injector for your application? Such large jumps may be due to improper injector sizing. The Geo engine is a fuel sipper rather than a gas guzzler so it would requi= re an injector that can meter fuel much more precisely. Just a thought. Jim --- On Mon, 5/11/09, Mike Fontenot wrote= : From: Mike Fontenot Subject: [FlyRotary] Re: Initial Tuning - Today To: "Rotary motors in aircraft" Date: Monday, May 11, 2009, 11:35 PM Tracy, >>All good except for (again) the MAP increasing.=A0=A0 My guess is that yo= u Assumed that the MAP went up when the RPM went up. =A0 This does not happ= en under these circumstances without increasing the throttle.=A0 See previo= us comments on this.=A0 Think of the engine as a vacuum pump (it is).=A0 If= you do something to make the engine (vacuum pump) turn faster WITHOUT open= ing the throttle more, the MAP is going to go DOWN (more vacuum), not UP, a= s the engine sucks more air through the same restriction.<< Right, yes I probably did assume that when the RPM went up so did the MAP. = Good explanation, I'll be sure to observe that next engine run. Its not Col= d Fusion (power de novo). >>Are you saying that the MI jumps around (up and down?) all the time, when= you move the mixture control, random direction=A0 when you move the mix co= ntrol, or what?=A0=A0 Position of O2 sensor (too close to end of pipe, too = cold a position, etc), exhaust leaks, engine miss, bad connections, poor gr= ound, and other things can cause bad indications. << When I was in Mode 3, and adjusting the mixture knob, the direction of chan= ge of the Mixture Knob and the increase and decrease of the Mixture Indicat= or were in the same direction. It was just that what I thought was a small = change on the Knob resulted in a big change on the Mixture Indicator. Same = when using the Program KNob and Store button. One push to increase injector= flow rate there could make the Mixture Indicator go from position 3 of 16 = to 11 of 16.=A0=A0 Movement of the Mixture Indicator always tracked the Mix= ture Knob or changes via the=A0 Program Knob, but I was expecting smooth in= creases. And in Mode 3 that generally did not happy, they were larger chang= es. I hate to use this term but 'twitchy'.=A0 Again, I will run it up again= and watch, note these specific things.=A0=20 I might try checking the wiring and putting a ground strap on the O2 sensor= as a first attempt.=20 --=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 --0-1232636239-1242137242=:2316 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable =
Mike,
Are you using the right fuel injector for your application?
Such large jumps may be due to improper injector sizing.
The Geo engine is a fuel sipper rather than a gas guzzler so it would = require
an injector that can meter fuel much more precisely.
Just a thought.
Jim

--- On Mon, 5/11/09, Mike Fontenot <m= ikef@apexconsultingservices.com> wrote:
From: Mike Fontenot <mikef@apexconsultingservices.= com>
Subject: [FlyRotary] Re: Initial Tuning - Today
To: "Rotary m= otors in aircraft" <flyrotary@lancaironline.net>
Date: Monday, May= 11, 2009, 11:35 PM

Tracy,

>>All good except for (again) t= he MAP increasing.   My guess is that you Assumed that the MAP we= nt up when the RPM went up.   This does not happen under these circums= tances without increasing the throttle.  See previous comments on this= .  Think of the engine as a vacuum pump (it is).  If you do somet= hing to make the engine (vacuum pump) turn faster WITHOUT opening the throt= tle more, the MAP is going to go DOWN (more vacuum), not UP, as the engine = sucks more air through the same restriction.<<

Right, yes I pr= obably did assume that when the RPM went up so did the MAP. Good explanatio= n, I'll be sure to observe that next engine run. Its not Cold Fusion (power= de novo).

>>Are you saying that the MI jumps around (up and d= own?) all the time, when you move the mixture control, random direction&nbs= p; when you move the mix control, or what?   Position of O2 sensor (too close to end of pipe, too cold a position, etc), exhaust leaks= , engine miss, bad connections, poor ground, and other things can cause bad= indications. <<

When I was in Mode 3, and adjusting the mixtu= re knob, the direction of change of the Mixture Knob and the increase and d= ecrease of the Mixture Indicator were in the same direction. It was just th= at what I thought was a small change on the Knob resulted in a big change o= n the Mixture Indicator. Same when using the Program KNob and Store button.= One push to increase injector flow rate there could make the Mixture Indic= ator go from position 3 of 16 to 11 of 16.   Movement of the Mixt= ure Indicator always tracked the Mixture Knob or changes via the  Prog= ram Knob, but I was expecting smooth increases. And in Mode 3 that generall= y did not happy, they were larger changes. I hate to use this term but 'twi= tchy'.  Again, I will run it up again and watch, note these specific things. 

I might try checking the wiring and putting= a ground strap on the O2 sensor as a first attempt.

--
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 & Servi= ces LLC
Lakewood, Colorado
303 / 731-6645
mikef AT apexconsultings= ervices 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
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