X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.25.9.100] verified) by logan.com (CommuniGate Pro SMTP 5.1.2) with ESMTP id 1591023 for flyrotary@lancaironline.net; Tue, 21 Nov 2006 21:18:54 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-098-162.carolina.res.rr.com [24.74.98.162]) by ms-smtp-01.southeast.rr.com (8.13.6/8.13.6) with SMTP id kAM2FwWM010671 for ; Tue, 21 Nov 2006 21:18:26 -0500 (EST) Message-ID: <000901c70ddc$9d62c2d0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" Subject: Spark Plug Fouling and Temperature Date: Tue, 21 Nov 2006 21:16:31 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0003_01C70DB2.50E393A0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0003_01C70DB2.50E393A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Regarding spark plug fouling, I knew I had come across an article that = indicated achieving certain minimum temperatures was a key factor in = improving (lessening) the fouling of spark plugs. IT sure seems that = hotter plugs may be part of the answer. =20 Ed Here is the URL for that article in case anyone is interested=20 http://www.sacskyranch.com/eng23.htm ..........Operating temperature of the spark plug insulator core nose is = one factor that governs formation of troublesome combustion deposits. To = help overcome this problem, selection of spark plugs with the proper = heat range should be made. Spark plugs are susceptible to carbon = deposits when the operating temperature of the core nose insulator is at = or below 800o F, but an increase of just 100o F is sufficient to = eliminate formation of these deposits. Also, lead deposits form because = the bromide scavenger contained in tetraethyl lead is nonactive at low = temperatures. At 900o F temperature, the bromide scavenger is fully = activated, disposing of lead deposits with combustion gases during = exhaust cycle. In this case, an increase of just 100o F was sufficient = to make the difference between a smooth and rough running engine. To = eliminate or keep this problem at a minimum, avoid prolonged idling at = low RPM, avoid power-off let downs, and after flooded starts run engine = at medium RPM before taxiing. Deposits formed between 1000o F and 1300o F are low in volume and = electrical conductivity and are least apt to cause spark plug fouling. = This is the reason for selecting a plug that will operate within the = aforementioned temperature range at all power settings. Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html ------=_NextPart_000_0003_01C70DB2.50E393A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Regarding spark plug fouling, I knew I had come = across an=20 article that indicated achieving certain minimum temperatures was a key = factor=20 in improving (lessening) the fouling of spark plugs. IT sure seems = that=20 hotter plugs may be part of the answer.

Ed

Here is the URL for that article in case = anyone is=20 interested

http://www.sacskyranch.com/= eng23.htm

..........Operating temperature of the spark plug insulator core = nose is=20 one factor that governs formation of troublesome combustion deposits. To = help=20 overcome this problem, selection of spark plugs with the proper heat = range=20 should be made. Spark plugs are susceptible to carbon deposits when the=20 operating temperature of the core nose insulator is at or below 800o F, = but an=20 increase of just 100o F is sufficient to eliminate formation of these = deposits.=20 Also, lead deposits form because the bromide scavenger contained in = tetraethyl=20 lead is nonactive at low temperatures. At 900o F temperature, the = bromide=20 scavenger is fully activated, disposing of lead deposits with combustion = gases=20 during exhaust cycle. In this case, an increase of just 100o F was = sufficient to=20 make the difference between a smooth and rough running engine. To = eliminate or=20 keep this problem at a minimum, avoid prolonged idling at low RPM, avoid = power-off let downs, and after flooded starts run engine at medium RPM = before=20 taxiing.

Deposits formed between 1000o F and 1300o F are low in volume and = electrical conductivity and are least apt to cause spark plug fouling. = This is=20 the reason for selecting a plug that will operate within the = aforementioned=20 temperature range at all power settings.

Ed Anderson
Rv-6A N494BW Rotary = Powered
Matthews,=20 NC
eanderson@carolina.rr.comhttp:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda= /index.html

------=_NextPart_000_0003_01C70DB2.50E393A0--