X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-lb0-f180.google.com ([209.85.217.180] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTPS id 5438811 for flyrotary@lancaironline.net; Mon, 12 Mar 2012 14:35:47 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.217.180; envelope-from=rwstracy@gmail.com Received: by lbon10 with SMTP id n10so1072532lbo.25 for ; Mon, 12 Mar 2012 11:35:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=jEG9NzJ6Oa0zgfoJSxgTlZJQQJoyf6RlzrXsv7/BRuE=; b=JhXysZNwJSRQcyI66ge37D749kwKKsn7cA2hzGcM83MsGqovRrid87hq3tDcgxsCSE ltttF4MCL9YnlMeTM5SY3yLpoxYGBVILjn2N7WiXETN8IdgY4qC7wZzsf3nxnEjPauKx bMfw0hWUddcKOlwJ4u55E6CoV46Go+WHp4+rnafr0omTbnwCFO/VuF7Fh1Bo7pMJN8DU MjtZwLXyIKOTOAaq/G4c30kNjkbCM+F9I/GxxtmNJZdBomHATw57/ZMK15OsxlgJR1bK lLE9FD+IMsGvC+atqzDjAbciUqshJelsaau5NtbfaL9I9pFR93RVMg2dK9Aha6CbvukC lsXQ== MIME-Version: 1.0 Received: by 10.112.82.197 with SMTP id k5mr5098525lby.83.1331577308965; Mon, 12 Mar 2012 11:35:08 -0700 (PDT) Received: by 10.112.94.179 with HTTP; Mon, 12 Mar 2012 11:35:08 -0700 (PDT) In-Reply-To: References: Date: Mon, 12 Mar 2012 14:35:08 -0400 Message-ID: Subject: Re: [FlyRotary] Re: Failure of an LS-1 D-580 type ignition coil From: Tracy To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=f46d04016c1b7de9ec04bb100087 --f46d04016c1b7de9ec04bb100087 Content-Type: text/plain; charset=ISO-8859-1 Quite possible you are running WAY too much fuel at lower MP if you haven't checked the monitor (ALWAYS check the monitor when in doubt). I didn't even consider the possibility that you had it so rich that the excess is running up the EGT as Lynn suggested. Auto tune is to be used after you rough it in manually, definitely check the monitor before invoking auto tune. Tracy On Mon, Mar 12, 2012 at 12:14 PM, Rob wrote: > ** > Thanks for you input Tracy. > > I haven't checked my mixture monitor under this condition yet. I'll check > that next time I fly but I do notice that the EM2 indicates that the fuel > flow, GPH, starts to be reduced as the MP decreases and the EGT increases. > I have been told that I should try to avoid EGT's above 1550 degrees and > definatelly not above 1600. In spite of these high temps upon decent I look > for overheated spark plugs and damage piston top and don't see any > indication of over heating. I really have to richen the mixture a lot to > keep the EGT under control so the question is am I just adding more fuel > where it is not needed when I'm reducing power. > I have been meaning to use the auto mixture feature in the EM2 to fix this > but I'm not sure it is necessary. Maybe I should just adjust the mixture so > it at leased stays below 1600 degrees. > Does this sound reasonable. > > Robert Bollinger > EC2 EM2 works great. > In Ford V6 > > ----- Original Message ----- > > *From:* Tracy > *To:* Rotary motors in aircraft > *Sent:* Monday, March 12, 2012 7:19 AM > *Subject:* [FlyRotary] Re: Failure of an LS-1 D-580 type ignition coil > > This is a different thing entirely. My guess is that your mixture is > changing at lower MP and raising the EGT. Assuming the ignition timing is > OK, this is probably what you want. Higher EGT due to leaner mixture at > low power wont hurt anything within limits. I don't know the limits of > this engine of course. What does your mixture monitor tell you under > these conditions compared to high throttle? > > Tracy > > On Sun, Mar 11, 2012 at 10:51 PM, Rob wrote: > >> ** >> Is this the same thing that happens when manifold pressure is reduced but >> RPM is increased, like when I reduce throttle to go to a lower altitude or >> for landing? When I do this my EGT starts to climb to 1600 or even 1700 >> degrees. This in on my Ford V6 with Tracy's EC2 and EM2. It dosen't make >> cents in this case either so it must be the same phenomenon. Do I need to >> worry about this climbing EGT or not? >> Thanks for any insights? >> >> Robert Bollinger >> >> ----- Original Message ----- >> *From:* Tracy >> *To:* Rotary motors in aircraft >> *Sent:* Saturday, March 10, 2012 8:22 AM >> *Subject:* [FlyRotary] Re: Failure of an LS-1 D-580 type ignition coil >> >> The other guys pretty much nailed it. Less burning in the chamber and >> more burning in the exhaust header. >> >> Tracy >> >> Sent from my iPad >> >> On Mar 9, 2012, at 11:53 PM, Dave wrote: >> >> On 3/9/2012 10:22 PM, DLOMHEIM@aol.com wrote: >> >> Tracy wrote: >As usual, the in-flight symptom was a rise in EGT on the >> affected rotor. >> >> Can someone describe the science behind a "rise in EGT" when we lose a >> single coil. I would have expected a drop in EGT due to less thorough >> burning of the mixture and therefore excess un-burnt fuel which I thought >> would provide cooler temps of the exhaust stream as it passes the EGT probe. >> >> Must be missing something very basic here... >> >> Thanks for any clarity! :) >> >> Doug Lomheim >> RV-9A / 13B FWF >> >> >> The rotor combustion space is long and narrow at TDC. If you ignite the >> fuel air charge in a rotary at tdc from only one end, the flame front >> progresses slowly from one end of the "combustion chamber" to the other. >> Two plugs (and coils) for each rotor are present in order to facilitate >> complete burning of the fuel-air charge from opposite ends, and to extract >> as much power from the charge as possible before the "power stroke" portion >> of rotor rotation uncovers an exhaust port and begins the "exhaust stroke" >> >> So.. in an abnormal condition characterized by a single coil failure (out >> of 4 coils).. the affected plug is dead... and the affected rotor has >> incomplete and SLOWER burning of the charge than normal. This delayed >> burning persists after the exhaust port is uncovered. So instead of exhaust >> gases (which have already lost heat to the block) passing by the EGT probe, >> you have actual flame front (from the still burning fuel air charge) >> passing the probe and combustion continues in the tailpipe. That explains >> why EGT on the affected rotor would rise in a rotary with dual plugs/coils >> per rotor. A single dead plug from fouling or other causes could also >> provide the same result. >> >> Make Sense? >> Dave (a lingering former rotorhead) >> >> > --f46d04016c1b7de9ec04bb100087 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Quite possible you are running WAY too much fuel at lower MP if you haven&#= 39;t checked the monitor=A0 (ALWAYS check the monitor when in doubt).=A0=A0= I didn't even consider the possibility that you had it so rich that th= e excess is running up the EGT as Lynn suggested.=A0 Auto tune is to be use= d after you rough it in manually,=A0 definitely check the monitor before in= voking auto tune.

Tracy

On Mon, Mar 12, 2012 at 12:14 P= M, Rob <rob@mum.edu= > wrote:
Thanks for you input Tracy.
=A0
I haven't checked my mixture monitor under th= is=20 condition yet. I'll check that next time I fly but I do notice that the= EM2=20 indicates that the fuel flow, GPH, starts to be reduced as the MP decreases= and=20 the EGT increases. I have been told that I should try to avoid EGT's ab= ove 1550=20 degrees and definatelly not above 1600. In spite of these high temps upon d= ecent=20 I look for overheated spark plugs and damage piston top and don't see a= ny=20 indication of over heating. I really have to richen the mixture a lot to ke= ep=20 the EGT under control so the question is am I just adding more fuel where i= t is=20 not needed when I'm reducing power.
I have been meaning to use the auto mixture featu= re=20 in the EM2 to fix this but I'm not sure it is necessary. Maybe I should= just=20 adjust the mixture so it at leased stays below 1600 degrees.
Does this sound reasonable.
=A0
Robert Bollinger
EC2 EM2 works great.
In Ford V6
=A0
----- Original Message -----
From:=20 Tracy
Sent: Monday, March 12, 2012 = 7:19=20 AM
Subject: [FlyRotary] Re: Failure of= an=20 LS-1 D-580 type ignition coil

This is a different thing entirely.=A0=A0 My guess is=20 that your mixture is changing at lower MP and raising the EGT.=A0=A0=20 Assuming the ignition timing is OK, this is probably what you want.=A0=20 Higher EGT due to leaner mixture at low power wont hurt anything within= =20 limits.=A0=A0 I don't know the limits of this engine of=20 course.=A0=A0 What does your mixture monitor tell you under these=20 conditions compared to high throttle?

Tracy

On Sun, Mar 11, 2012 at 10:51 PM, Rob <rob@mum.edu<= /a>> wrote:
Is this the same thing that happens when mani= fold=20 pressure is reduced but RPM is increased, like when I reduce throttle t= o go=20 to a lower altitude or for landing? When I do this my EGT starts to cli= mb to=20 1600 or even 1700 degrees. This in on my Ford V6 with Tracy's EC2 a= nd=20 EM2.=A0=A0 It dosen't make cents in this case either so it must be = the=20 same phenomenon. Do I need to worry about this climbing EGT or=20 not?
Thanks for any insights?
=A0
Robert Bollinger
----- Original Message -----
Sent: Saturday, March 10, 2012 = 8:22=20 AM
Subject: [FlyRotary] Re: Failur= e of=20 an LS-1 D-580 type ignition coil

The other guys pretty much nailed it. =A0 Less burning in the=20 chamber and more burning in the exhaust header.

Tracy

Sent from my iPad

On Mar 9, 2012, at 11:53 PM, Dave <david.staten@gmail.com> wrote:=

On 3/9/2012 10:22 PM, DLO= MHEIM@aol.com wrote:=20
Tracy wrote:=A0 >As usual, the in-flight symptom was a ri= se=20 in EGT on the affected rotor.
=A0
Can someone describe the science behind a "rise in EGT&= quot; when we=20 lose a single coil.=A0 I would have expected a drop in EGT due to= =20 less thorough burning of the mixture and therefore=A0excess=20 un-burnt fuel which I thought would provide=A0cooler temps of the= =20 exhaust stream as=A0it passes the=A0EGT probe.
=A0
Must be missing something very basic here...
=A0
Thanks for any clarity!=A0 :)
=A0
Doug Lomheim
RV-9A / 13B FWF

The rotor combu= stion=20 space is long and narrow at TDC. If you ignite the fuel air charge = in a=20 rotary at tdc from only one end, the flame front progresses slowly = from=20 one end of the "combustion chamber" to the other. Two plu= gs (and coils)=20 for each rotor are present in order to facilitate complete burning = of=20 the fuel-air charge from opposite ends, and to extract as much powe= r=20 from the charge as possible before the "power stroke" por= tion of rotor=20 rotation uncovers an exhaust port and begins the "exhaust=20 stroke"

So.. in an abnormal condition characterized by = a single=20 coil failure (out of 4 coils).. the affected plug is dead... and th= e=20 affected rotor has incomplete and SLOWER burning of the charge than= =20 normal. This delayed burning persists after the exhaust port is=20 uncovered. So instead of exhaust gases (which have already lost hea= t to=20 the block) passing by the EGT probe, you have actual flame front (f= rom=20 the still burning fuel air charge) passing the probe and combustion= =20 continues in the tailpipe. That explains why EGT on the affected ro= tor=20 would rise in a rotary with dual plugs/coils per rotor. A single de= ad=20 plug from fouling or other causes could also provide the same resul= t.=20

Make Sense?
Dave (a lingering former=20 rotorhead)


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