X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao106.cox.net ([68.230.241.40] verified) by logan.com (CommuniGate Pro SMTP 5.2.3) with ESMTP id 2977550 for flyrotary@lancaironline.net; Fri, 20 Jun 2008 23:34:14 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.40; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao106.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20080621033324.SCKU7004.fed1rmmtao106.cox.net@fed1rmimpo03.cox.net> for ; Fri, 20 Jun 2008 23:33:24 -0400 Received: from wills ([68.105.85.56]) by fed1rmimpo03.cox.net with bizsmtp id gTZT1Z00R1CvZmk04TZabf; Fri, 20 Jun 2008 23:33:34 -0400 Message-ID: <004101c8d34f$9232f7b0$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: The SAGA continues; More checking basics and development progress Date: Fri, 20 Jun 2008 20:33:27 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003E_01C8D314.E51ED970" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_003E_01C8D314.E51ED970 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I too still have intermittent surging issues that havent been fully = conquered. Doesnt happen all the time. Always in the 2000 - 3000 RPM = range. Usually happens when I'm taxiing and back off the throttle. In my = case the A/F reading is useless. The engine surges rhythmically at about = a 1Hz rate with RPMs varying several hundred, MAP varying from high to = low (hard to pin down exact numbers - its moving around too much), and = the A/F bouncing back and forth from the rich stop to the lean stop. = Fiddling with mixture always stops it, but its a little disconcerting = (and embarassing) when it happens (usually as I'm taxiing away from the = crowd at the local EAA chapter while everyone is watching). For a while = I thought adding some capacity to the MAP sensing line (Dave Leonard's = suggestion) had cured it, but not entirely. I'll need to get this = figured out before it flies. Could be a real problem if it happens on = short final. I occasionally have a pretty good backfire at the secondary staging = point. The operational solution seems to be to not linger in the area - = just advance the throttle or retard it right on through and it seems to = be OK. Advancing the throttle too slowly almost guarantees a big pop! = I'm told it's particularly impressive after dark! I havent worked on the tuning in months while I've been tweaking other = little issues in prep for my DAR inspection. Just about ready to get = back to it. I'm sure i'll get it more or less figured out eventually. Mike Wills RV-4 N144MW ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Friday, June 20, 2008 7:06 PM Subject: [FlyRotary] Re: The SAGA continues; More checking basics and = development progress Chris,=20 As you've probably read from the archives surging is usually caused by = an overly lean air-fuel ratio. What is your A/F reading during the = surging? =20 Mark S. On Fri, Jun 20, 2008 at 8:41 PM, Christopher Barber = wrote: Well, to continue the saga, I have not run the new 13b much since I = got it running a few weeks ago due to the EM2 not showing oil pressure = as it should. It was giving me erratic readings like -1, -3 etc. I = hand propped the engine before I ran it and oil pumped through the = system fine....much onto the hangar floor...alas, the sacrifices for = certainty ;-). Also, during my short runs everything heated up in the = oil system evenly and the oil temp stayed pretty much in line with = coolant temp. BUT, since I was not sure if this was a gage/sender issue = or an actual oil system problem I was very cautious about my few short = engine runs. Well, today while dreading the idea of dropping my pan, I happened = across an extra oil pressure sender (still in the package) I happened to = have. I had seen it laying around for a while, but didn't give it much = thought until I was thinking about dropping the pan. Low and behold, The = problem was the sender. I am getting good pressure reading now, along = with coolant and oil temp. Yeah. I am surprised at the temps as they = seem to be staying in check considering the 95 + degree Houston weather. I am able to start the engine, shut it down and restart it = (something I was not able to do with the old engine). It is somewhat = difficult, but seems to be getting easier as I continue to tweak things = (ie timing). I am trying to do the various tuning via Tracy's manual. = To be honest a lot of the information in the manual is seemingly = abstract until I actually get to the step and/or problem. So, tonight, = I got it to run, and it seems to run better, but...... I am having a surging problem. It seems intermittent, but it just = may be I have not been setting the throttle quite the same way as I get = use to it all. Also, I have had the coil C/B pop on me several times = now....it seems as if this is when the engine is near or at idle. I = have not had a chance to look into this as of yet. Also, I have gotten = a number of horrendously loud/powerful backfires. Not sure what changes = as the engine may have run fine. It backfires when attempting to start. = I wait a few minutes and it may then start. Gee, isn't inconsistent = crap fun I just did a search of the archives on the surging issue, but have = just started reading the 105 post on the topic. Seems our own Mr. Slade = had the same problem back in the day . Well, it is the middle of my work week and I gotta turn in soon, but = I wanted to share that it seems as if actual progress is being made = (hmmmm, wonder what will screw this positive statement up) as the = Saga continues. All the best, Chris ------=_NextPart_000_003E_01C8D314.E51ED970 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I too still have intermittent surging = issues that=20 havent been fully conquered. Doesnt happen all the time. Always in the = 2000 -=20 3000 RPM range. Usually happens when I'm taxiing and back off the = throttle. In=20 my case the A/F reading is useless. The engine surges rhythmically at = about a=20 1Hz rate with RPMs varying several hundred, MAP varying from high to low = (hard=20 to pin down exact numbers - its moving around too much), and the A/F = bouncing=20 back and forth from the rich stop to the lean stop. Fiddling with = mixture always=20 stops it, but its a little disconcerting (and embarassing) when it = happens=20 (usually as I'm taxiing away from the crowd at the local EAA chapter = while=20 everyone is watching). For a while I thought adding some capacity to the = MAP=20 sensing line (Dave Leonard's suggestion) had cured it, but not = entirely.=20 I'll need to get this figured out before it flies. Could be a real = problem if it=20 happens on short final.
 
I occasionally have a pretty good = backfire at the=20 secondary staging point. The operational solution seems to be to not = linger in=20 the area - just advance the throttle or retard it right on through and = it seems=20 to be OK. Advancing the throttle too slowly almost guarantees a big = pop!=20 I'm told it's particularly impressive after dark!
 
I havent worked on the tuning in months = while I've=20 been tweaking other little issues in prep for my DAR inspection. Just = about=20 ready to get back to it. I'm sure i'll get it more or less figured out=20 eventually.
 
Mike Wills
RV-4 N144MW
----- Original Message -----
From:=20 Mark = Steitle=20
Sent: Friday, June 20, 2008 = 7:06 PM
Subject: [FlyRotary] Re: The = SAGA=20 continues; More checking basics and development progress

Chris,

As you've probably read from the = archives=20 surging is usually caused by an overly lean air-fuel ratio.  What = is your=20 A/F reading during the surging? 

Mark S.

On Fri, Jun 20, 2008 at 8:41 PM, Christopher = Barber=20 <CBarber@texasattorney.net&g= t;=20 wrote:
Well, to continue the saga, I have = not run the=20 new 13b much since I got it running a few weeks ago due to the EM2 = not=20 showing oil pressure as it should.  It was giving me erratic = readings=20 like -1, -3 etc.  I hand propped the engine before I ran it and = oil=20 pumped through the system fine....much onto the hangar floor...alas, = the=20 sacrifices for certainty ;-).  Also, during my short runs = everything=20 heated up in the oil system evenly and the oil temp stayed pretty = much in=20 line with coolant temp.  BUT, since I was not sure if this was = a=20 gage/sender issue or an actual oil system problem I was very = cautious about=20 my few short engine runs.
 
Well, today while dreading the idea = of dropping=20 my pan, I happened across an extra oil pressure sender (still in the = package) I happened to have.  I had seen it laying around for a = while,=20 but didn't give it much thought until I was thinking about dropping = the pan.=20 Low and behold, The problem was the sender.  I am getting good = pressure=20 reading now, along with coolant and oil temp. Yeah.  I am = surprised at=20 the temps as they seem to be staying in check considering the 95 + = degree=20 Houston weather.
 
I am able to start the engine, shut = it down and=20 restart it (something I was not able to do with the old = engine).  It is=20 somewhat difficult, but seems to be getting easier as I continue to = tweak=20 things (ie timing).  I am trying to do the various tuning via = Tracy's=20 manual.  To be honest a  lot of the information in the = manual is=20 seemingly abstract until I actually get to the step and/or = problem. =20 So, tonight, I got it to run, and it seems to run better,=20 but......
 
I am having a surging = problem.  It seems=20 intermittent, but it just may be I have not been setting the = throttle quite=20 the same way as I get use to it all.  Also, I have had the coil = C/B pop=20 on me several times now....it seems as if this is when the engine is = near or=20 at idle.  I have not had a chance to look into this as of = yet. =20 Also, I have gotten a number of horrendously loud/powerful = backfires. =20 Not sure what changes as the engine may have run fine.  It = backfires=20 when attempting to start.  I wait a few minutes and it may then = start.  Gee, isn't inconsistent crap fun <g>
 
I just did a search of the archives = on the=20 surging issue, but have just started reading the 105 post on the=20 topic.  Seems our own Mr. Slade had the same problem back in = the=20 day <g>.
 
Well, it is the middle of my work = week and I=20 gotta turn in soon, but I wanted to share that it seems as if actual = progress is being made (hmmmm, wonder what will screw this positive=20 statement up<g>) as the Saga continues.
 
All the best,
 
Chris

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