X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from web83905.mail.sp1.yahoo.com ([69.147.92.105] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with SMTP id 4487563 for flyrotary@lancaironline.net; Thu, 30 Sep 2010 11:50:23 -0400 Received-SPF: none receiver=logan.com; client-ip=69.147.92.105; envelope-from=keltro@att.net Received: (qmail 59689 invoked by uid 60001); 30 Sep 2010 15:49:41 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=att.net; s=s1024; t=1285861780; bh=/W5pmfa68PVFSQpfAC3T8BZDpxs5MAV8VZhsLdjF6fI=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=Ik8cv1dNkJXSYpK4vEEjaVLRbC5czAMsJ3B5zRXtYCzegSKgmAYUbh8op0DcUQSfafTZTnEq/UdHODvWxRDRpIOBya6qallfPVIsNag3QxbMygG0Tgu/mUuGBuAUffD9ZoEjeKXQX0It7lW3IPZ16F8DMBr0KN+g0ranJCkJb7g= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=att.net; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=fuy0OOAt+p/3h1kTlCTE15hH0skPWsz7KOskpuREUi97x5TSI3fdu1bEHcfDZhcTJ/ud7mLT/uQwohTFvCOGbPSZ4QvVJXAM3NeTfoShb6V8XYy7na9aB1kPDJ/qsbypzDwKNEIvwK5Yy0wAW052AbYxsMl1LBGGdeF3Y1G7Ndc=; Message-ID: <978858.56315.qm@web83905.mail.sp1.yahoo.com> X-YMail-OSG: NYj4ueAVM1nNbUCILILaEizo7v9EykAZlaIB3dCm5sirwIQ vUJktpLgvBvm1Sgk4lx2mZDDs842B04QfMjN8wHoDkxfOpDXTSW5pjlkkvG0 JhG7bTn3vzLbnaMKNs3EWk6mEK2JyaPm54HMtHBmg32AQ8sffKZg036eUojq cxh2MyuTRV5PQ0VGZ46Px7fAoTDwXo484ulOM1EovKRI1bUt_ZGER1FgC7FZ xkUNlzOi5lxYWsMnE1g4t42oqLl4_aA8SJvQ1j2PFNpseyRAHYGfzJY466vU ib4qXIbTTU3sy1OZThN37ip1i3RwU5g-- Received: from [208.114.43.242] by web83905.mail.sp1.yahoo.com via HTTP; Thu, 30 Sep 2010 08:49:40 PDT X-Mailer: YahooMailRC/497 YahooMailWebService/0.8.105.279950 References: Date: Thu, 30 Sep 2010 08:49:40 -0700 (PDT) From: Kelly Troyer Subject: Re: [FlyRotary] New SAG Theory Discussions of SAG To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-61455576-1285861780=:56315" --0-61455576-1285861780=:56315 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Steve and Group,=0A=A0=A0=A0=A0 Another thought............Do other engines= suffer from this =0Aanomaly.............Are the combustion=0Atemperatures = significantly higher for the Rotary or is it some other factor such =0Aas d= uty cycle since=0Athe plugs are asked to do the equivalent=A0work of=A0a si= x cylinder four cycle =0Aengine with essentially=A0=0Ano rest time between = ignition events ??..............=0AKelly Troyer=0A"Dyke Delta"_13B ROTARY E= ngine=0A"RWS"_RD1C/EC2/EM2=0A"Mistral"_Backplate/Oil Manifold =0A=0A=0A=0A= =0A________________________________=0AFrom: Kelly Troyer = =0ATo: Rotary motors in aircraft =0ASent: Thu,= September 30, 2010 10:30:28 AM=0ASubject: [FlyRotary] New SAG Theory Discu= ssions of SAG=0A=0A=0ASteve,=0A=A0=A0 Realizing that=A0any improvement in p= lug life before "SAG" starts=A0have yet to =0Abe proved=0Acan you give us t= he plug make and part # from "Racing Beat"=A0and what heat range =0A# is = =0A=0Aclaimed (Also realizing heat range #'s are not the same between plug = =0Amanufacturers)...=0AKelly Troyer=0A"Dyke Delta"_13B ROTARY Engine=0A"RWS= "_RD1C/EC2/EM2=0A"Mistral"_Backplate/Oil Manifold =0A=0A=0A=0A=0A__________= ______________________=0AFrom: Steven W. Boese =0ATo: Rota= ry motors in aircraft =0ASent: Thu, September = 30, 2010 10:14:06 AM=0ASubject: [FlyRotary] Re: New SAG Theory Discussions = of SAG=0A=0A=0AEd,=0A=A0=0AYou take good notes.=0A=A0=0AJust a couple of cl= arifications:=A0 The decrease in the thermal conductivity of =0Athe copper = core may be the result of thermal cycling=A0causing development of =0Aporos= ity within the copper.=A0 This=A0is independent of the corrosion going on = =0Abetween the Mn alloy electrode sheath and the insulator.=A0 So there are= two =0Aessentially independent mechanisms contributing to the heat range c= hange of the =0Aspark plug with age.=A0 =0A=0A=A0=0AThe development of the = porosity within the copper is not particularly affected =0Aby the type of f= uel whereas the corrosion between the Mn alloy sheath and the =0Ainsulator= =A0is accelerated by the use of 100LL.=0A=A0=0AThe cure is still to install= new spark plugs.=A0 =0A=A0=0AI have colder spark plugs from Racing Beat th= at are recommended for prolonged =0Ause=A0in high RPM high power applicatio= ns.=A0 At best, the colder plugs will merely =0Adelay the onset of SAG but= =A0won't prevent it from happening eventually.=A0 It will =0Abe some time b= efore the results of using those plugs will be known.=0A=A0=0ASteve Boese= =0A=A0=0A=A0=A0 =0A=A0=0A=0A________________________________=0AFrom: Rotary= motors in aircraft [flyrotary@lancaironline.net] On Behalf Of Ed =0AAnders= on [eanderson@carolina.rr.com]=0ASent: Thursday, September 30, 2010 8:46 AM= =0ATo: Rotary motors in aircraft=0ASubject: [FlyRotary] New SAG Theory Disc= ussions of SAG=0A=0A=0AIn a nut shell, Steve's excellent data gathering (ho= w many of use have access to =0Aa scanning electron microscope or spectrum = analyzer {:>)) and analysis indicates =0Aa possible alternative reason for = SAG other than fouling.=A0=0A=A0=0A=A0It basically boils down to a theory o= f pre-ignition based on the deteorating =0Aheat removal capacity of the plu= g.=A0 =0A=0A=A0=0AThere is a copper core (the photos showing the two cores)= in the center of the =0Aceramic cone which is responsible for conducting 9= 0% of the heat away from the =0Acenter electrode.=A0 Based on Steve's' elec= tron microscope viewing of two cores =0A(one new and one having been used i= n a 100LL environment), it appears that the =0Aplug using leaded gasoline h= as corrosion occurring on the boundary between this =0Acopper core and the = surrounding (hot) elements.=A0 This layer of corrosion hinders =0Aheat remo= val from the plug leading to parts of the plug becoming hot enough to =0Atr= igger pre-ignition.=0A=A0=0AThis SAG tends to happened at high power settin= gs and reducing power tends to =0Amake it go away (for a while).=A0 Steve's= theory is that the plug encounters max =0Aheat and temperature at high pow= er settings and that reducing the power permits =0Athe plug to cool off eno= ugh for the pre-ignition to go away (for a while).=0A=A0=0ASo we now have t= wo theories - one is the fouled plug and one of the overheated =0Aplug caus= ing SAG.=A0 Preignition generally leads to detonation which does not =0Aapp= ear to be happening (at least no one is finding the typical detonation dama= ge =0Ato the rotary engine).=A0 A possible reason is the quenching effect o= f the less =0Athan optimum shape of the rotary combustion space may tend to= delay or prevent =0Athe onset of detonation damage that one would expect f= rom continuous preignition =0Acaused by a too hot plug.=0A=A0=0AI believe S= teve intends to see if he can find some colder plugs (the ones that =0Acond= uct heat better) and see if that extends the time between SAG.=A0 Currently= I =0Afind that roughly 25-30 hours is about the max I can get using 100LL = before SAG =0Asets in, whereas Tracy and others have well over 150 hours us= ing unleaded =0AMogas.=A0 So if the colder plugs extend the time before SAG= , I would say that =0Apretty much would suggest Steve's theory is correct -= if Not, then perhaps the =0Afouled Plug theory still has merit or it could= be some other phenomena =0Ahappening.=0A=A0=0ASteve, my apologies if I did= not present your case as well as you could=0A=A0=0AEd=0A=A0=0AEdward L. An= derson=0AAnderson Electronic Enterprises LLC=0A305 Reefton Road=0AWeddingto= n, NC 28104=0Ahttp://www.andersonee.com=0Ahttp://www.eicommander.com=0A=0A= =A0=0A.=0A=A0=0A=A0=0A=0A=0AFrom: Bill Bradburry =0ASent: Thursday, Septemb= er 30, 2010 9:59 AM=0ATo: Rotary motors in aircraft =0ASubject: [FlyRotary]= Discussions of SAG=0A=0AI understand that there was a presentation on SAG = at the meeting.=A0 Can someone =0Ago over the alternative theory with the o= nes of us that were not in attendance?=A0 =0AIt looked like someone had a s= canning electron microscope photo that they were =0Ashowing!=A0 Wow!=A0 Are= we getting sophisticated or what!!=A0 Was this an explanation =0Aof the ca= use, or ideas for prevention, both??=0A=A0=0ABill B --0-61455576-1285861780=:56315 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
=0A
Steve and Group,
=0A
   &nb= sp; Another thought............Do other engines suffer from this anomaly...= ..........Are the combustion
=0A
temperatures significantly higher= for the Rotary or is it some other factor such as duty cycle since
= =0A
the plugs are asked to do the equivalent work of a six cy= linder four cycle engine with essentially 
=0A
no rest time b= etween ignition events ??..............
=0A
 
Kelly Troy= er
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Bac= kplate/Oil Manifold =0A

=0A

=0A
=0A
=0AFrom: Kelly Troyer <keltro@att.net>
To: Rotary motors in aircraft <flyrotary@lancaironl= ine.net>
Sent: Thu, S= eptember 30, 2010 10:30:28 AM
Subje= ct: [FlyRotary] New SAG Theory Discussions of SAG

= =0A
can you give us the plug make and part # from "Racing Beat" and = what heat range # is
=0A
claimed (Also realizing heat range #'s a= re not the same between plug manufacturers)...
=0A
 
Kel= ly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistr= al"_Backplate/Oil Manifold =0A

=0A

=0A
=0A
=0A= From: Steven W. Boese <SBoese@uwyo.edu>
To: Rotary motors in aircraft <flyrota= ry@lancaironline.net>
Sent: Thu, September 30, 2010 10:14:06 AM
Subject: [FlyRotary] Re: New SAG Theory Discussions of S= AG

=0A=0A=0A=0A=0A=0A=0A
=0A
Ed,
=0A<= DIV> 
=0A
You take good notes.
=0A
 
=0A
Just a co= uple of clarifications:  The decrease in the thermal conductivity of t= he copper core may be the result of thermal cycling causing developmen= t of porosity within the copper.  This is independent of the corr= osion going on between the Mn alloy electrode sheath and the insulator.&nbs= p; So there are two essentially independent mechanisms contributing to the = heat range change of the spark plug with age. 
=0A
 
=0A
The development of the porosity within the copper is not particul= arly affected by the type of fuel whereas the corrosion between the Mn allo= y sheath and the insulator is accelerated by the use of 100LL.<= /DIV>=0A
 
=0A
The cure is still to install new= spark plugs. 
=0A
 
=0A
I have colder spark plugs from Racing Beat th= at are recommended for prolonged use in high RPM high power applicatio= ns.  At best, the colder plugs will merely delay the onset of SAG but&= nbsp;won't prevent it from happening eventually.  It will be some time= before the results of using those plugs will be known.
= =0A
 
=0A
Steve Boese
=0A
 
=0A
   <= /FONT>
=0A
=  
=0A
=0A=0AFrom:= Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of Ed An= derson [eanderson@carolina.rr.com]
Sent: Thursday, September 30, = 2010 8:46 AM
To: Rotary motors in aircraft
Subject: [Fl= yRotary] New SAG Theory Discussions of SAG

=0A
=0A
=0A
In a nut shell, Steve's excellent data= gathering (how many of use have access to a scanning electron microscope o= r spectrum analyzer {:>)) and analysis indicates a possible alternative = reason for SAG other than fouling. 
=0A
 
=0A
 It basically boils= down to a theory of pre-ignition based on the deteorating heat removal cap= acity of the plug. 
=0A
&nb= sp;
=0A
There is a copper core (the photos show= ing the two cores) in the center of the ceramic cone which is responsible f= or conducting 90% of the heat away from the center electrode.  Based o= n Steve's' electron microscope viewing of two cores (one new and one having= been used in a 100LL environment), it appears that the plug using leaded g= asoline has corrosion occurring on the boundary between this copper core an= d the surrounding (hot) elements.  This layer of corrosion hinders hea= t removal from the plug leading to parts of the plug becoming hot enough to= trigger pre-ignition.
=0A
 =
=0A
This SAG tends to happened at high power s= ettings and reducing power tends to make it go away (for a while).  St= eve's theory is that the plug encounters max heat and temperature at high p= ower settings and that reducing the power permits the plug to cool off enou= gh for the pre-ignition to go away (for a while).
=0A
 
=0A
So we now have = two theories - one is the fouled plug and one of the overheated plug causin= g SAG.  Preignition generally leads to detonation which does not appea= r to be happening (at least no one is finding the typical detonation damage= to the rotary engine).  A possible reason is the quenching effect of = the less than optimum shape of the rotary combustion space may tend to dela= y or prevent the onset of detonation damage that one would expect from cont= inuous preignition caused by a too hot plug.
=0A
 
=0A
I believe Steve inte= nds to see if he can find some colder plugs (the ones that conduct heat bet= ter) and see if that extends the time between SAG.  Currently I find t= hat roughly 25-30 hours is about the max I can get using 100LL before SAG s= ets in, whereas Tracy and others have well over 150 hours using unleaded Mo= gas.  So if the colder plugs extend the time before SAG, I would say t= hat pretty much would suggest Steve's theory is correct - if Not, then perh= aps the fouled Plug theory still has merit or it could be some other phenom= ena happening.
=0A
 
= =0A
Steve, my apologies if I did not present your ca= se as well as you could
=0A
 = ;
=0A
Ed
=0A
 
=0A
Edward L. Anderson
Anders= on Electronic Enterprises LLC
305 Reefton Road
Weddington, NC 28104http://www.andersonee.com
http://www.eicommander.com
= =0A
 
=0A
.<= /FONT>
=0A
 
=0A
 
=0A
=0A
=0A
=0A=0A
Sent: Thursday, September 30, 2010 9:59 A= M
=0A= =0A
Subject: [FlyRotary] Discussions of SAG
=0A=

=0A
=0A

I understand that there was a presentation on SAG at th= e meeting.  Can someone go over the alternative theory with the ones o= f us that were not in attendance?  It looked like someone had a scanni= ng electron microscope photo that they were showing!  Wow!  Are w= e getting sophisticated or what!!  Was this an explanation of the caus= e, or ideas for prevention, both??

=0A

 

=0A

Bill B

--0-61455576-1285861780=:56315--