X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from willowsprings.uwyo.edu ([129.72.10.31] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTPS id 4488476 for flyrotary@lancaironline.net; Thu, 30 Sep 2010 22:29:50 -0400 Received-SPF: none receiver=logan.com; client-ip=129.72.10.31; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht2.uwyo.edu (ponyexpress-ht2.uwyo.edu [10.84.60.209]) by willowsprings.uwyo.edu (8.14.4/8.14.4) with ESMTP id o912TD8d005228 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL) for ; Thu, 30 Sep 2010 20:29:13 -0600 (MDT) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9813:248c:2d68:a28b]) by ponyexpress-ht2 ([10.84.60.209]) with mapi; Thu, 30 Sep 2010 20:29:12 -0600 From: "Steven W. Boese" To: "flyrotary@lancaironline.net" Date: Thu, 30 Sep 2010 20:29:11 -0600 Subject: lead fouled plugs Thread-Topic: lead fouled plugs Thread-Index: AQHLYRBufxHuAqntB0GH90Mu608jyw== Message-ID: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: multipart/alternative; boundary="_000_E1AA3B1AF41D8049B1E3FBD5E225626004E2453FEAponyexpressmb_" MIME-Version: 1.0 --_000_E1AA3B1AF41D8049B1E3FBD5E225626004E2453FEAponyexpressmb_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable The following is an exchange between Ed and me earlier today. I hope Ed do= esn't mind my forwarding it to the list. For some reason, my replies to the list are unreasonably large and cannot b= e read (at least by me) in the archives. I hope that I'm not distributing = a virus and that creating new messages instead of simply replying works OK. It has occurred to me that it may be possible to initiate SAG by going to a= hotter plug instead of waiting for a used one to malfunction. If I can do= this with the engine on the test stand, that may enable studying the SAG p= henomenon with less risk (to me- not necessarily the engine). A starting p= oint may be using stock leading plugs (BUR7EQ) in all four locations. Steve Boese Ed and all, The replacement colder plugs I thought I'd try are: 11524-NGK Spark Plug<br>BR10EIX Racing @ 9.44 as copied from the order to Racing Beat. As I mentioned in the talk at Paducah, I tried all sorts of chemical cleani= ng methods and the lead remained on the insulator. My thought is that the = lead may be incorporated into a glass type of phase that has significantly = less thermal conductivity than the alumina insulator. I agree that the fac= t that the room temperature resistance of the material on the insulator bei= ng over 10 raised to the 13th power ohms with the connecting points as clos= e as possible (about 0.030" apart) does not mean that the material does no= t become conductive at higher temperatures. The fact that the EGT drops and the coolant and oil temperatures rise durin= g SAG whereas the EGT rises and the coolant and oil temperatures drop when = disabling either the leading or trailing ignition coil suggests to me that = SAG is not a result of the spark plug misfiring. I have not seen the kind of damage to my spark plugs that the photo of the = pre-ignition shows either. Alternative explanations for the observations are more than welcome and I a= m willing to try to test these alternatives as much as I am able and encour= age others to do the same within the limits of acceptable risk. I have no = personal investment in one theory over another, but am just interested in u= nderstanding what is going on. Steve Boese ________________________________ From: Ed Anderson [eanderson@carolina.rr.com] Sent: Thursday, September 30, 2010 11:39 AM To: Steven W. Boese Subject: Lead Fouled Plugs Hi Steve, Was looking into colder plugs myself and came up on this at the Champion SP= site http://www.championsparkplugs.com/sparkplug411.asp?kw=3DLead+Fouling&mfid= =3D2 Lead fouling can be difficult to diagnose. Although it usually ap= pears as yellowish brown deposits on the insulator nose, some fu= el additives may also cause similar discoloration (and are harmless). Also,= a fouled plug can typically be detected with a simple resistance tester, w= hereas a lead fouled plug will read within specs (while at room temperature= ). Also, the ease of fouling will vary on different engines even = with the same lead exposure; this is because lead compounds combine at diff= erent temperatures. Those formed at 370-470=B0C (700-790=B0F) having the gr= eatest likelihood of causing lead resistance (fouling) on a plug. I thought this was interesting , I know you attempted to measure the resi= stance of the Lead coating. It appears (if I read this correctly) that whi= le normally (carbon?) fouled plugs will give you a lower resistance reading= , it appears that Lead fouled plugs will give a normal resistance reading a= t room temperature. So apparently the lead conduction (fouling) must take = place at elevated (running ) temperatures. Just thought I would throw it i= n the hopper {:>). Here is a photo of what they say a pre-ignition plug looks like - My plugs = never looked like that except for the one time during first 60 hours of fli= ght when I inadvertently set the static ignition timing to 45 Deg BTDC. Sa= gged plugs never approach this condition in my experience. Ed [https://wyosecure.uwyo.edu/owa/,DanaInfo=3Duwmail.uwyo.edu,SSL+attachment.= ashx?id=3DRgAAAACySZi3%2fqPKTZDbCPHiI%2fCkBwBcR9RI8y6EQKsAkSX0zTfIAAAABjqyA= ADhqjsa9B2ASbHj%2b9XiJWJgAATiRWFBAAAJ&attcnt=3D1&attid0=3DEACma1xHGgilT6Yz4= jT7NreE] plug damaged due to Sustained pre-Ignition Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com --_000_E1AA3B1AF41D8049B1E3FBD5E225626004E2453FEAponyexpressmb_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
The following is an exchange between Ed and me earlier today.&nbs= p; I hope Ed doesn't mind my forwarding it to the list.
 
For some reason, my replies to the list are unre= asonably large and cannot be read (at least by me) in the archives.  I= hope that I'm not distributing a virus and that creating new messages inst= ead of simply replying works OK.
 
It has occurred to me that it may be possible to= initiate SAG by going to a hotter plug instead of waiting for a used one t= o malfunction.  If I can do this with the engine on the test stand,&nb= sp;that may enable studying the SAG phenomenon with less risk (to me- not necessarily the engine).  A starting point= may be using stock leading plugs (BUR7EQ) in all four locations.
 
Steve Boese
 
Ed and all,
 
The replacement colder plugs I though= t I'd try are:
 
11524-NGK Spark Plug&lt;br&gt;BR10EIX Racing @ 9.4= 4
=  
as copi= ed from the order to Racing Beat.
 
As I mentioned in the tal= k at Paducah, I tried all sorts of chemical cleaning methods and the lead r= emained on the insulator.  My thought is that the lead may be&nbs= p;incorporated into a glass type of phase that has significantly less thermal conductivity than the alumina insulator.&nb= sp; I agree that the fact that the room temperature resistance of the mater= ial on the insulator being over 10 raised to the 13th power ohms with the c= onnecting points as close as possible (about 0.030" apart)  does not mean that the material does not b= ecome conductive at higher temperatures.
 
The fact that the EG= T drops and the coolant and oil temperatures rise during SAG wh= ereas the EGT rises and the coolant and oil temperatures drop w= hen disabling either the leading or trailing ignition coil suggests to me that SAG is not a result of the spark plug misfir= ing.
 
I have not seen the = kind of damage to my spark plugs that the photo of the pre-ignition sh= ows either.
 
Alternative explanations = for the observations are more than welcome and I am willing to try to test = these alternatives as much as I am able and encourage others to do the same= within the limits of acceptable risk.  I have no personal investment in one theory over another, but am just inte= rested in understanding what is going on.
 
Steve Boese
 
 
From: Ed Anderson= [eanderson@carolina.rr.com]
Sent: Thursday, September 30, 2010 11:39 AM
To: Steven W. Boese
Subject: Lead Fouled Plugs

Hi Steve,
 
Was looking into colder plugs myself and came up = on this at the Champion SP site
 
Lead fouling can be difficult to diagnose. Although it usually appears as ye= llowish brown deposits on the insulator nose, some fuel additives may also cause simi= lar discoloration (and are harmless). Also, a fouled plug can typically be = detected with a simple resistance tester, whereas a lead fouled plug will read within= specs (while at room temperature). Also, the ease of fouling will vary on different engines even with the same lead exposure= ; this is because lead compounds combine at different temperatures. Those f= ormed at 370-470=B0C (700-790=B0F) having the greatest likelihood of causin= g lead resistance (fouling) on a plug.
 
I thought this was interesting ,  I kno= w you attempted to measure  the resistance of the Lead coating.&n= bsp; It appears (if I read this correctly) that while normally (carbon?) fo= uled plugs will give you a lower resistance reading, it appears that Lead fouled plugs will give a normal resistance reading at room tempe= rature.  So apparently the lead conduction (fouling) must take place a= t elevated (running ) temperatures.  Just thought I would throw it in = the hopper {:>).
 
Here is a photo of what they say a pre-ignition p= lug looks like - My plugs never looked like that except for the one time du= ring first 60 hours of flight when I inadvertently set the static ignition = timing to 45 Deg BTDC.  Sagged plugs never approach this condition in my experience.
 
Ed
plug damaged due to Sustained pre-Ignition<= /font>
 
 
Ed
 
Edward L. Anderson
Anderson Electronic Enterprises LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee.com
http://www.eicommander.com
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