X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost01.isp.att.net ([207.115.11.51] verified) by logan.com (CommuniGate Pro SMTP 5.3.9) with ESMTP id 4488035 for flyrotary@lancaironline.net; Thu, 30 Sep 2010 17:00:33 -0400 Received-SPF: none receiver=logan.com; client-ip=207.115.11.51; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-85-141-241.mco.bellsouth.net[98.85.141.241]) by isp.att.net (frfwmhc01) with SMTP id <20100930205947H0100dncnae>; Thu, 30 Sep 2010 20:59:47 +0000 X-Originating-IP: [98.85.141.241] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: New SAG Theory Discussions of SAG Date: Thu, 30 Sep 2010 16:59:48 -0400 Message-ID: <5A9F3EAA81CF4DD482BCC228E54C44BE@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01CB60C0.E4B3FF60" X-Mailer: Microsoft Office Outlook 11 Thread-Index: Actg39nnRGwztQBvQvKL5dHnl4c2UgAAntUg X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 This is a multi-part message in MIME format. ------=_NextPart_000_0006_01CB60C0.E4B3FF60 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit You found a plug with a large cavity in the copper core??? Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese Sent: Thursday, September 30, 2010 4:40 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: New SAG Theory Discussions of SAG Ed, That's the way I see it too. The change in the thermal conductivity of the electrode core (if it is indeed a factor) seems to take much longer to become a problem and may simply not be significant when 100LL is the predominant fuel. The longevity of the plugs when not exposed to 100LL seems to support this. Since I have found only the one plug with the large cavity in the copper core, it is not possible to draw general conclusions from this. This plug may have suffered from a manufacturing defect. However, the less dramatic porosity development shown in the SEM photos is seen in all the older plugs and is less likely to be anomalous. Steve Boese _____ From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of Ed Anderson [eanderson@carolina.rr.com] Sent: Thursday, September 30, 2010 9:46 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: New SAG Theory Discussions of SAG Thanks for the clarification, Steve However, that raises a new question. If the porosity is even a significant contributing factor to thermal cycling, I would expect the same thermal cycling deterioration with Mogas or 100LL - not certain why it would be different between the two? IF not significantly different, then that leaves the lead enhanced corrosion as the major culprit - at least that is the way it appears to me. Agree, regardless of cause - the answer is replace the plugs - however, if you discover the colder plugs last longer - then that would permit me to reduce my bushel basket storage of old spark plugs - cleaning (even if it were possible) does not appear to be a option any longer {:>) Ed Edward L. Anderson Anderson Electronic Enterprises LLC 305 Reefton Road Weddington, NC 28104 http://www.andersonee.com http://www.eicommander.com ------=_NextPart_000_0006_01CB60C0.E4B3FF60 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

You found a plug with a large = cavity in the copper core???

 

Bill B

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese
Sent: Thursday, September = 30, 2010 4:40 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = New SAG Theory Discussions of SAG

 

Ed,

 

That's the way I see it = too.  The change in the thermal conductivity of the electrode core (if it is = indeed a factor) seems to take much longer to become a problem and may simply not = be significant when 100LL is the predominant fuel.  The longevity = of the plugs when not exposed to 100LL seems to support = this.

 

Since I have found only the = one plug with the large cavity in the copper core, it is not possible to = draw general conclusions from this.  This plug may have suffered from a = manufacturing defect.  However, the less dramatic porosity development shown in the SEM photos is seen in all the older plugs and is less likely to = be anomalous. 

 

Steve = Boese

 

 

From: = Rotary motors in aircraft [flyrotary@lancaironline.net] On = Behalf Of Ed Anderson [eanderson@carolina.rr.com]
Sent: Thursday, September = 30, 2010 9:46 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = New SAG Theory Discussions of SAG

Thanks for the clarification, = Steve

 

However, that raises a new question.  If the porosity is even  a significant contributing factor to thermal cycling, I would = expect the same thermal cycling deterioration with Mogas or 100LL - not = certain why it would be different between the two?  IF not significantly different, then that leaves the lead enhanced corrosion as the major = culprit - at least that is the way it appears to me.

 

Agree, regardless of cause - the = answer is replace the plugs - however, if you discover the colder plugs last = longer - then that would permit me to reduce my bushel basket storage of old = spark plugs - cleaning (even if it were possible) does not appear to be a option any = longer {:>)

 

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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