X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 932935 for flyrotary@lancaironline.net; Thu, 19 Jan 2006 12:55:11 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-025-165.carolina.res.rr.com [24.74.25.165]) by ms-smtp-04-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id k0JHsK1w022054 for ; Thu, 19 Jan 2006 12:54:22 -0500 (EST) Message-ID: <000a01c61d21$672b1200$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" Subject: Spark Plug Fouling Date: Thu, 19 Jan 2006 12:54:32 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01C61CF7.7E0FEAB0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0007_01C61CF7.7E0FEAB0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I believe that most of us understood that leaded gasoline can lead to = spark plug fouling. It turns out even with the "Scavenger" compounds = it apparently will still happened. See article below: I also read one report that address aircraft engine effect. It = basically said that if the CHT is not kept over 350F the scavenger = effectiveness is minimal. So this may be why aircraft sparkplugs do not = seem to foul as often as the auto plugs (higher CHT). =20 URL :http://www.petroleumbazaar.com/MS/msappli2.htm During combustion TEL (Tetraethyl lead ) forms an oxide of lead which is = not volatile and so should tend to deposit on the combustion chamber, = valves, spark plugs, etc. with harmful effects. To counteract this. = "Scavenger" compounds, such as ethylene dibromide and ethylene = dichloride, are mixed with TEL so that on combustion more volatile = compounds of lead are formed, resulting in most of the metal passing out = with exhaust gas. The TEL together with the scavengers and a dye to = indicate the poisonous nature of the compound is known as "ethyl fluid". = Despite the use of decavenger compounds, it can give rise to such = difficulties as: sparkplug fouling, surface ignition, exhaust valve = failure and octane requirement increase. Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ------=_NextPart_000_0007_01C61CF7.7E0FEAB0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I believe that most of us understood that leaded = gasoline=20 can lead to spark plug fouling.   It turns out even with the=20 "Scavenger" compounds it apparently will still happened.  See = article=20 below:
 
I also read one report that address aircraft = engine=20 effect.  It basically said that if the CHT is not kept over 350F = the=20 scavenger effectiveness is minimal.  So this may be why aircraft = sparkplugs=20 do not seem to foul as often as the auto plugs (higher CHT).  =
 
 
URL=20 :http://www.petroleumbazaar.com/MS/msappli2.htm
 
 
During combustion TEL (Tetraethyl=20 lead ) forms an oxide of lead which is not volatile and so = should tend=20 to deposit on the combustion chamber, valves, spark plugs, etc. with = harmful=20 effects. To counteract this. "Scavenger" compounds, such as ethylene = dibromide=20 and ethylene dichloride, are mixed with TEL so that on combustion more = volatile=20 compounds of lead are formed, resulting in most of the metal passing out = with=20 exhaust gas. The TEL together with = the scavengers=20 and a dye to indicate the poisonous nature of the compound is known as = "ethyl=20 fluid".
 
 
Despite the use of decavenger = compounds, it can=20 give rise to such difficulties as: sparkplug fouling, surface ignition, = exhaust=20 valve failure and octane requirement increase.
 
 
Ed Anderson
Rv-6A N494BW Rotary = Powered
Matthews,=20 NC
eanderson@carolina.rr.com
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