X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db02.mx.aol.com ([205.188.91.96] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5514793 for flyrotary@lancaironline.net; Sun, 29 Apr 2012 22:18:30 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.96; envelope-from=Lehanover@aol.com Received: from mtaomg-da03.r1000.mx.aol.com (mtaomg-da03.r1000.mx.aol.com [172.29.51.139]) by imr-db02.mx.aol.com (8.14.1/8.14.1) with ESMTP id q3U2Hn5n019511 for ; Sun, 29 Apr 2012 22:17:49 -0400 Received: from core-moc001a.r1000.mail.aol.com (core-moc001.r1000.mail.aol.com [172.29.195.1]) by mtaomg-da03.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 2313EE000085 for ; Sun, 29 Apr 2012 22:17:49 -0400 (EDT) From: Lehanover@aol.com Message-ID: <5a181.124c7774.3ccf504c@aol.com> Date: Sun, 29 Apr 2012 22:17:49 -0400 (EDT) Subject: Re: [FlyRotary] Re: Hiccup To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_5a181.124c7774.3ccf504c_boundary" X-Mailer: AOL 9.6 sub 5004 X-Originating-IP: [173.88.30.23] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1335752269; bh=eUObrzfMU4kSd6WJCSl6cNwfRAZnF4jaZXjM4B14q0o=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=MQcShNEGN4YUp3pIsW1+au13RYnJPsoyinrCQEd5KUjBJZm8rJisq63VSLu2vFyMQ d0Mvf4wkeTwRMqSxqmAiUOOBRuSEgYm3X5Xj+hK/diwt2A4qcN9sXQ8ml3C6u3jUPA S5aogvRscpxxEs2B441sG+fLMjMxhWsKxvCBS3l4= X-AOL-SCOLL-SCORE: 0:2:464821280:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d338b4f9df64d5364 --part1_5a181.124c7774.3ccf504c_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Sounds like a bit of air leaking into the headers proving enough oxygen to light unburned fuel in the headers or muffler. Look for combustion products leaking from any joints. Lowest pressure is closer to the flange right on the engine. Lynn E. Hanover In a message dated 4/29/2012 5:53:12 P.M. Eastern Daylight Time, bbradburry@bellsouth.net writes: I am not talking about a closed throttle descent. I am talking about a full throttle descent. When I started to descend, I just set the autopilot for a 500ft/min descent and let er go. Prop and throttle were left alone. The mixture was already at the mid-point because I can't tell where I am since the mixture graph is not working at present. I am also getting this hiccup at idle. I have always had that, so I thought it was normal. It is not as strong at idle as it is at cruise. But still a quick BUHT! From time to time... Bill B -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ernest Christley Sent: Sunday, April 29, 2012 5:05 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Hiccup You can cut the fuel on descent, just like in a car, and still get the lube from mixed oil by cutting the ignition a few cycles ahead of the fuel cut. Tracy wrote: >The only thing I can think of that would match that symptom is an intermittent open in one of the crank sensor connections. > >If it happened only at high throttle, that would match the symptom I had way back when I had a failure of the welds that fixed the sun gear to the input shaft. I assume your drive is either a later model after I went to the pinned input shaft or it has been retrofitted with a pin. In this case, The symptom FEELS exactly like an engine miss or backfire but is really a momentary slipping of the input shaft before it temporarily friction welds itself back to the sun gear. This happens at high power setting, not at low throttle in a descent though so I don't think that's what's happening here unless you have two unrelated problems. > >An engine miss during descent can be caused by the engine running at a very low MP (due to windmilling prop) where there is not enough combustion chamber pressure to give reliable combustion. Cars avoid this (in a downhill coasting situation) by cutting the fuel injection completely. I chose not to do this on the EC2/3 because we depend on a little fuel-oil injection to lubricate the apex seals. What many builders perceive as a MISS is often an occasional FIRE when there happens to be enough fuel and MP to combust. > >This is only general info so don't take it as the gospel on what your engine is doing. I'm a long way from your engine and going on very little info. > >Tracy > >Sent from my iPad > >On Apr 28, 2012, at 6:34 AM, "Bill Bradburry" wrote: > >> The hiccup is like a backfire. It really shakes the engine. You can feel it thru the airframe. But it is quick, like it was a single event. BUP! Then it is smooth again for a minute or two. Much closer together if you are in a powered decent. >> >> Bill >> >> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy >> Sent: Friday, April 27, 2012 5:36 PM >> To: Rotary motors in aircraft >> Subject: [FlyRotary] Re: Hiccup >> >> Don't know about the hiccup but you can easily calibrate the airspeed. Go to calibration screen for TAS, adjust the sensor offset parameter to one less than the current ADC reading. Do this at zero airspeed of course. >> >> Tracy >> Sent from my iPad >> >> On Apr 27, 2012, at 2:58 PM, "Bill Bradburry" wrote: >> >>> I am experiencing an occasional hiccup while in cruise and more often during a decent under power. I am pretty certain that I saw a comment on this previously from Tracy but I have not been able to find it. Can someone set me straight on what to do about this? >>> >>> My mixture graph is not working and I will be sending the EM-2 to Tracy as soon as he returns from Colorado. I also show a true airpspeed of 22 mph in the hangar and it seems to be about that much or a little more in error in cruise. I don't think I can calibrate this item? >>> >>> Bill B >> -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html --part1_5a181.124c7774.3ccf504c_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Sounds like a bit of air leaking into the headers proving enough oxyge= n to=20 light unburned fuel in the headers or muffler. Look for combustion products= =20 leaking from any joints. Lowest pressure is closer to the flange right on t= he=20 engine.
 
Lynn E. Hanover 
 
In a message dated 4/29/2012 5:53:12 P.M. Eastern Daylight Time,=20 bbradburry@bellsouth.net writes:
= I am not=20 talking about a closed throttle descent.  I am talking about a=20 full
throttle descent.  When I started to descend, I just set the= =20 autopilot for a
500ft/min descent and let er go.  Prop and thrott= le=20 were left alone.  The
mixture was already at the mid-point becaus= e I=20 can't tell where I am since
the mixture graph is not working at=20 present.

I am also getting this hiccup at idle.  I have alway= s had=20 that, so I thought
it was normal.  It is not as strong at idle as= it=20 is at cruise.  But still a
quick BUHT! From time to=20 time...

Bill B

-----Original Message-----
From: Rotary m= otors=20 in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Ernest= =20 Christley
Sent: Sunday, April 29, 2012 5:05 PM
To: Rotary motors in= =20 aircraft
Subject: [FlyRotary] Re: Hiccup

You can cut the fuel o= n=20 descent, just like in a car, and still get the lube
from mixed oil by= =20 cutting the ignition a few cycles ahead of the fuel cut.



T= racy=20 <rwstracy@gmail.com> wrote:

>The only thing I can think o= f=20 that would match that symptom is an
intermittent open in one of the cr= ank=20 sensor connections.
>
>If it happened only at high throttle, = that=20 would match the symptom I had
way back when I had a failure of the wel= ds=20 that fixed the sun gear to the
input shaft.  I assume your drive = is=20 either a later model after I went to
the pinned input shaft or it has = been=20 retrofitted with a pin.   In this
case, The symptom FEELS ex= actly=20 like an engine miss or backfire but is
really a momentary slipping of = the=20 input shaft before it temporarily
friction welds itself back to the su= n=20 gear.  This happens at high power
setting, not at low throttle in= a=20 descent though so I don't think that's
what's happening here unless yo= u=20 have two unrelated problems.
>
>An engine miss during descent= can=20 be caused by the engine running at a very
low MP (due to windmilling p= rop)=20 where there is not enough combustion
chamber pressure to give reliable= =20 combustion.   Cars avoid this (in a
downhill coasting situat= ion)=20 by cutting the fuel injection completely.  I
chose not to do this= on=20 the EC2/3 because we depend on a little fuel-oil
injection to lubricat= e the=20 apex seals.  What many builders perceive as a
MISS is often an=20 occasional FIRE when there happens to be enough fuel and MP
to=20 combust.
>
>This is only general info so don't take it as the= =20 gospel on what your
engine is doing.  I'm a long way from your en= gine=20 and going on very little
info. =20
>
>Tracy
>
>Sent from my iPad
>
>On = Apr=20 28, 2012, at 6:34 AM, "Bill Bradburry"=20 <bbradburry@bellsouth.net>
wrote:
>
>> The hiccup= is=20 like a backfire.  It really shakes the engine.  You can
feel= it=20 thru the airframe.  But it is quick, like it was a single event.
= BUP!=20 Then it is smooth again for a minute or two.  Much closer together= =20 if
you are in a powered decent.
>> 
>>=20 Bill
>> 
>> From: Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On
Behalf Of Tracy
>> Se= nt:=20 Friday, April 27, 2012 5:36 PM
>> To: Rotary motors in=20 aircraft
>> Subject: [FlyRotary] Re: Hiccup
>> =20
>> Don't know about the hiccup but you can easily calibrate the= =20 airspeed.
Go to calibration screen for TAS, adjust the sensor offset= =20 parameter to one
less than the current ADC reading.  Do this at z= ero=20 airspeed of course.
>>
>> Tracy
>> Sent from = my=20 iPad
>>
>> On Apr 27, 2012, at 2:58 PM, "Bill Bradburr= y"=20 <bbradburry@bellsouth.net>
wrote:
>>
>>> I= am=20 experiencing an occasional hiccup while in cruise and more often
durin= g a=20 decent under power.  I am pretty certain that I saw a comment on
= this=20 previously from Tracy but I have not been able to find it.  Can=20 someone
set me straight on what to do about this?
>>> = ;=20
>>> My mixture graph is not working and I will be sending th= e=20 EM-2 to Tracy
as soon as he returns from Colorado.  I also show a= true=20 airpspeed of 22 mph
in the hangar and it seems to be about that much o= r a=20 little more in error
in cruise.  I don't think I can calibrate th= is=20 item?
>>> 
>>> Bill B
>>=20

--
Homepage:  http://www.flyrotary.com/
Archive and=20 UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
<= BR>
--
Homepage: =20 http://www.flyrotary.com/
Archive and UnSub:  =20 http://mail.lancaironline.net:81/lists/flyrotary/List.html
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