X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ispmxmta06-srv.alltel.net ([166.102.165.167] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with ESMTP id 1149466 for flyrotary@lancaironline.net; Sat, 10 Jun 2006 21:53:34 -0400 Received-SPF: none receiver=logan.com; client-ip=166.102.165.167; envelope-from=trpeters@alltel.net Received: from ispmxaamta05-gx.alltel.net ([69.40.76.32]) by ispmxmta06-srv.alltel.net with ESMTP id <20060611015249.GNCV7967.ispmxmta06-srv.alltel.net@ispmxaamta05-gx.alltel.net> for ; Sat, 10 Jun 2006 20:52:49 -0500 Received: from 3F8JX51SHAW ([69.40.76.32]) by ispmxaamta05-gx.alltel.net with SMTP id <20060611015248.IPAZ19332.ispmxaamta05-gx.alltel.net@3F8JX51SHAW> for ; Sat, 10 Jun 2006 20:52:48 -0500 Message-ID: <002601c68cf9$c453f620$6400a8c0@shaw.shawinc.com> From: "Timothy Peters" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Ignition Failure Date: Sat, 10 Jun 2006 21:52:59 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0023_01C68CD8.3D0FFB80" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 This is a multi-part message in MIME format. ------=_NextPart_000_0023_01C68CD8.3D0FFB80 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Perry! That was what I was looking for. =20 I didn't mention names because I didn't want things to get personal, but = I guess everything is out in the open now... =20 Every conversion I have seen so far has some non-redundant items. One = example on the Subaru side, I have seen backup ignition controllers, but = all the engines I have seen only have one sparkplug per cylinder. Is = redundancy needed there? I'm not certain. Normally I would say no. = But I just had a plug failure strand me while riding my motorcycle. = (First time ever for me... and no, it's not a V-Twin) So now it raises = a red flag... there have been other red flags, but this was just the = first thing to come to mind. =20 I do know that a 91 Porsche 911 engine had dual plugs, dual distributor, = dual coils. Maybe replace the distributors with electronic ignition. = Parts would be pricey though... typing out loud again.=20 So now I have confirmation that a crank angle sensor failure will shut = down an engine. But it also appears that a crank angle sensor failure = is extremely rare (difficult to quantify, but there seems to be a = general consensus on this). Something else that would be interesting to = find out is if failure usually occurs during operation (stress), or = during idle time (corrosion, etc.). If the primary failure point is = before startup, then the risk is relatively benign (not happening in the = air). I hope everyone here (and other mailing lists for that matter) continue = to report their successes and failures. I have been following (and = cheering on! :-) ) John Slade for a while now. I just hope you don't = give up on the A/C system John, now that you have moved out of the = tropics and north of the Mason-Dixon line! =20 Back to lurking! -TP ----- Original Message -----=20 From: Perry Mick=20 To: Rotary motors in aircraft=20 Sent: Saturday, June 10, 2006 11:49 AM Subject: [FlyRotary] Re: Ignition Failure The crank angle sensor is a single point of failure. There is only = one, so it's not redundant even if you have two controllers. However = from my experience driving RX-7s (70 miles round trip to work for the = last 10 years) I've never seen one fail. Haven't seen an ECU fail = either. Occassionally one of my cars wouldn't start, I would unplug and = then reseat the crank angle sensor connector and it would then start. = I've only seen this phenomenon on one car. Probably just needed some = contact cleaner. Generally I think any problem with the crank angle sensor would mean = the engine wouldn't run at all.=20 Might be good to have one controller running on the stock crank angle = sensor and a second running from an independent sensor on the e-shaft = front pulley. You can't have redundancy everywhere. I have one cranks sensor and one = ecu and my engine has never quit running in 600 hours. If you really = want redundancy build a plane like a twin-engine Defiant, that can truly = fly on one engine.=20 Perry ----------------- I understand that it's totally natural to feel defensive in this = situation. I know you may find this hard to believe, but the goal of the = post is to help others reduce risk. It's not a personal attack. There's = no rotary reference in it anywhere. As far as the readers know it's a = piston engine. But I hope there's at least one person on this list that = sees value of looking at the other causes. The essence of the post is accurate. Doesn't matter if you are near = home base or not. Ignition failure is very high risk item. An ECU that = was better at self diagnoses would have greatly reduced your risk. On = your car, it would be recognized immediately. Ecu would say "Hey, my cam = sensor just went thru it's normal 50 pulses per revolution with the = normal 5 and 8 ms. gaps. But I didn't get the normal 20 pulses and = signal gaps from the crank sensor. Turn on warning lamp and crank code. = Use cam sensor for timing info." You don't see value in discussing stuff = like this? If you guys just used toothed wheel with pulse gaps, then the = ECU could easily self diagnose.=20 You know what was cool on the other list? Guys came back with = "confessions" of how this parallels a problem they encountered. 2 guys = said, "yeah, I had partial failure, thought it was x, took off only to = find it was y". Then other guys described changes they made to system = that totally eliminated the risk. Some really creative stuff. Then we = discussed just how risky crank sensor really is...we see one ever 1 1/2 = to 2 years. Etc. Etc. Very positive experience that may save someone's = life. That's the goal. -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru = 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design = info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Fri, 09 Jun 2006 23:30:00 -0400 John Slade = writes: Hi Tim, Isn't it wonderful how stories get twisted around as they fly from = list to list. Obviously this particular twisted story relates to my = recent experience, so let's dilute the fun a little by adding some = truth. ------=_NextPart_000_0023_01C68CD8.3D0FFB80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks Perry!
 
That was what I was looking for. =20
 
I didn't mention names because I didn't = want things=20 to get personal, but I guess everything is out in the open now... =20
 
Every conversion I have seen so = far has some=20 non-redundant items.  One example on the Subaru side, I have = seen=20 backup ignition controllers, but all the engines I have seen only have = one=20 sparkplug per cylinder.  Is redundancy needed there?  I'm not=20 certain.  Normally I would say no.  But I just had a plug = failure=20 strand me while riding my motorcycle.  (First time ever for me... = and no,=20 it's not a V-Twin)  So now it raises a red flag...  there have = been=20 other red flags, but this was just the first thing to come to = mind. =20
 
I do know that a 91 Porsche 911 engine = had dual=20 plugs, dual distributor, dual coils.  Maybe replace the = distributors with=20 electronic ignition.  Parts would be pricey though... = typing out=20 loud again.
 
So now I have confirmation that a crank = angle=20 sensor failure will shut down an engine.  But it also appears that = a crank=20 angle sensor failure is extremely rare (difficult to quantify, but there = seems=20 to be a general consensus on this).  Something else that would be=20 interesting to find out is if failure usually occurs during operation = (stress),=20 or during idle time (corrosion, etc.).  If the primary failure = point is=20 before startup, then the risk is relatively benign (not happening in the = air).
 
I hope everyone here (and other mailing = lists for=20 that matter) continue to report their successes and failures.  I = have been=20 following (and cheering on! :-) ) John Slade for a while now.  I = just hope=20 you don't give up on the A/C system John, now that you have moved = out of=20 the tropics and north of the Mason-Dixon line! 
 
Back to lurking!
 
-TP
----- Original Message -----
From:=20 Perry = Mick=20
Sent: Saturday, June 10, 2006 = 11:49=20 AM
Subject: [FlyRotary] Re: = Ignition=20 Failure

The crank angle sensor is a single point of failure. = There is=20 only one, so it's not redundant even if you have two controllers. = However from=20 my experience driving RX-7s (70 miles round trip to work for the last = 10=20 years) I've never seen one fail. Haven't seen an ECU fail either.=20 Occassionally one of my cars wouldn't start, I would unplug and then = reseat=20 the crank angle sensor connector and it would then start. I've only = seen this=20 phenomenon on one car. Probably just needed some contact=20 cleaner.

Generally I think any problem with the crank angle = sensor=20 would mean the engine wouldn't run at all.

Might be good to = have one=20 controller running on the stock crank angle sensor and a second = running from=20 an independent sensor on the e-shaft front pulley.

You can't = have=20 redundancy everywhere. I have one cranks sensor and one ecu and my = engine has=20 never quit running in 600 hours. If you really want redundancy build a = plane=20 like a twin-engine Defiant, that can truly fly on one engine.=20

Perry

-----------------
I understand that it's totally natural to feel defensive in this=20 situation. I know you may find this hard to believe, but the goal of = the post=20 is to help others reduce risk. It's not a personal attack. There's no = rotary=20 reference in it anywhere. As far as the readers know it's a piston=20 engine.  But I hope there's at least one person on this list that = sees value of looking at the other causes.
 
The essence of the post is accurate. Doesn't matter if you are = near home=20 base or not. Ignition failure is very high risk item. An ECU that was = better=20 at self diagnoses would have greatly reduced your risk. On your car, = it would=20 be recognized immediately. Ecu would say "Hey, my cam sensor just went = thru=20 it's normal 50 pulses per revolution with the normal 5 and 8 ms. gaps. = But I=20 didn't get the normal 20 pulses and signal gaps from the crank = sensor.=20 Turn on warning lamp and crank code. Use cam sensor for timing info." = You=20 don't see value in discussing stuff like this? If you guys just used = toothed=20 wheel with pulse gaps, then the ECU could easily self diagnose.
 
You know what was cool on the other list? Guys came back with=20 "confessions" of how this parallels a problem they encountered. 2 = guys=20 said, "yeah, I had partial failure, thought it was x, took off only to = find it=20 was y". Then other guys described changes they made to system that = totally=20 eliminated the risk. Some really creative stuff. Then we discussed = just how=20 risky crank sensor really is...we see one ever 1 1/2 to 2 years. Etc. = Etc.=20 Very positive experience that may save someone's life. That's the = goal.
 

-al wick
Artificial intelligence in cockpit, Cozy IV = powered by=20 stock Subaru 2.5
N9032U 200+ hours on engine/airframe from = Portland,=20 Oregon
Prop construct, Subaru install, Risk assessment, Glass panel = design=20 info:
http://www.maddyhome.com/canardpages/pages/alwick/index.h= tml
 
 
 
On Fri, 09 Jun 2006 23:30:00 -0400 John Slade <sladerj@bellsouth.net> writes:
Hi = Tim,
Isn't it=20 wonderful how stories get twisted around as they fly from list to = list.=20 Obviously this particular twisted story relates to my recent = experience, so=20 let's dilute the fun a little by adding some=20 truth.

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