X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from lincoln.lisco.com ([69.18.32.37] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5438885 for flyrotary@lancaironline.net; Mon, 12 Mar 2012 15:15:43 -0400 Received-SPF: none receiver=logan.com; client-ip=69.18.32.37; envelope-from=rob@mum.edu Received: from robertsdellxp (76-76-232-229.lisco.net [76.76.232.229]) by lincoln.lisco.com (Postfix) with SMTP id 168D92BF0F for ; Mon, 12 Mar 2012 14:15:06 -0500 (CDT) Message-ID: <3859EFC6A33F48D1859FE1A1C7620796@robertsdellxp> From: "Rob" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Failure of an LS-1 D-580 type ignition coil Date: Mon, 12 Mar 2012 14:15:05 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000B_01CD005A.85C96F40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 This is a multi-part message in MIME format. ------=_NextPart_000_000B_01CD005A.85C96F40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Lynn nd Tracy. These insights will help me figure this out.=20 ----- Original Message -----=20 From: Tracy=20 To: Rotary motors in aircraft=20 Sent: Monday, March 12, 2012 1:35 PM Subject: [FlyRotary] Re: Failure of an LS-1 D-580 type ignition coil 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.=20 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.=20 Does this sound reasonable. Robert Bollinger EC2 EM2 works great. In Ford V6 ----- Original Message -----=20 From: Tracy=20 To: Rotary motors in aircraft=20 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 -----=20 From: Tracy=20 To: Rotary motors in aircraft=20 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:=20 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.=20 Make Sense? Dave (a lingering former rotorhead) ------=_NextPart_000_000B_01CD005A.85C96F40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks Lynn nd Tracy. These insights = will help me=20 figure this out.
 
----- Original Message -----
From:=20 Tracy
Sent: Monday, March 12, 2012 = 1:35=20 PM
Subject: [FlyRotary] Re: = Failure of an=20 LS-1 D-580 type ignition coil

Quite possible you are running WAY too much fuel at = lower MP if=20 you haven't checked the monitor  (ALWAYS check the monitor when = in=20 doubt).   I didn't even consider the possibility that you = had it so=20 rich that the excess is running up the EGT as Lynn suggested.  = Auto tune=20 is to be used after you rough it in manually,  definitely check = the=20 monitor before invoking auto tune.

Tracy

On Mon, Mar 12, 2012 at 12:14 PM, Rob <rob@mum.edu> wrote:
Thanks for you input Tracy.
 
I haven't checked my mixture monitor under = this=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=20 and the EGT increases. I have been told that I should try to avoid = EGT's=20 above 1550 degrees and definatelly not above 1600. In spite of these = high=20 temps upon decent I look for overheated spark plugs and damage = piston top=20 and don't see any indication of over heating. I really have to = richen the=20 mixture a lot to keep the EGT under control so the question is am I = just=20 adding more fuel where it is not needed when I'm reducing power.=20
I have been meaning to use the auto mixture = feature in=20 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.
 
Robert Bollinger
EC2 EM2 works great.
In Ford V6
 
----- Original Message -----
From: = Tracy
To: Rotary = motors in=20 aircraft
Sent: Monday, March 12, = 2012 7:19=20 AM
Subject: [FlyRotary] Re: = Failure of=20 an LS-1 D-580 type ignition coil

This is a different thing entirely.   My = guess is=20 that your mixture is changing at lower MP and raising the = EGT.  =20 Assuming the ignition timing is OK, this is probably what you = want. =20 Higher EGT due to leaner mixture at low power wont hurt anything = within=20 limits.   I don't know the limits of this engine of=20 course.   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> wrote:
Is this the same thing that happens when = manifold=20 pressure is reduced but RPM is increased, like when I reduce = throttle to=20 go to a lower altitude or for landing? When I do this my EGT = starts to=20 climb to 1600 or even 1700 degrees. This in on my Ford V6 with = Tracy's=20 EC2 and EM2.   It dosen't make cents in this case = either so it=20 must be the same phenomenon. Do I need to worry about this = climbing EGT=20 or not?
Thanks for any insights?
 
Robert Bollinger
----- Original Message ----- =
From: Tracy
To: Rotary motors=20 in aircraft
Sent: Saturday, March = 10, 2012=20 8:22 AM
Subject: [FlyRotary] = Re: Failure=20 of an LS-1 D-580 type ignition coil

The other guys pretty much nailed it.   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, DLOMHEIM@aol.com wrote:=20
Tracy wrote:  >As usual, the in-flight = symptom was a=20 rise in EGT on the affected rotor.
 
Can someone describe the science behind a "rise in = EGT" when=20 we lose a single coil.  I would have expected a drop = in EGT=20 due to less thorough burning of the mixture and=20 therefore excess un-burnt fuel which I thought would=20 provide cooler temps of the exhaust stream as it = passes=20 the EGT probe.
 
Must be missing something very basic here...
 
Thanks for any clarity!  :)
 
Doug Lomheim
RV-9A / 13B FWF

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

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

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

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