X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-03.southeast.rr.com ([24.25.9.102] verified) by logan.com (CommuniGate Pro SMTP 5.1.2) with ESMTP id 1595311 for flyrotary@lancaironline.net; Wed, 22 Nov 2006 20:55:48 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; 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-03.southeast.rr.com (8.13.6/8.13.6) with SMTP id kAN1tGaS008605 for ; Wed, 22 Nov 2006 20:55:16 -0500 (EST) Message-ID: <000001c70ea2$6cd333e0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Spark Plug Fouling and Temperature Date: Wed, 22 Nov 2006 20:49:57 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0004_01C70E77.C5293E20" 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_0004_01C70E77.C5293E20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Its interesting, we I use 100LL I usually get 25 hours on a set of = plugs. I wonder what factors might make the difference between your = time interval and mine - "Plugs Up"?. I have not run across any chart = that indicated anything other than a plug digit which indicated a = "hotter" or a "colder version". I think I may try hotter plugs and see = if they make any difference. Ed=20 ----- Original Message -----=20 From: Perry Mick=20 To: Rotary motors in aircraft=20 Sent: Wednesday, November 22, 2006 8:26 PM Subject: [FlyRotary] Spark Plug Fouling and Temperature Ed, thanks for that article. I installed the hotter plugs, BUR6EQ leading and BUR8EQ trailing a = month or so ago. I guess I'll have to start burning 100LL to see if it fixes the = fouling problem. I usually only burn it when I'm travelling and have no other choice, = but don't have any trips planned soon. For me, it only takes 4 hours of continuous 100LL use to get SAG and = fouled leading plugs on the next takeoff. Is there any data anywhere that might tell us what temperature BUR6EQ, = 7EQ, 8EQ, and 9EQ plugs operate at in an RX-7? Perry http://www.ductedfan.com ----- 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_0004_01C70E77.C5293E20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Its interesting, we I use 100LL I usually get 25 = hours on=20 a set of plugs.  I wonder what factors might make the difference = between=20 your time interval and mine - "Plugs Up"?.  I have not run = across any=20 chart that indicated anything other than a plug digit which indicated a = "hotter"=20 or a "colder version".  I think I may try  hotter plugs and = see if=20 they make any difference.
 
Ed 
----- Original Message -----
From:=20 Perry = Mick=20
Sent: Wednesday, November 22, = 2006 8:26=20 PM
Subject: [FlyRotary] Spark Plug = Fouling=20 and Temperature

Ed, thanks for that article.
I installed = the hotter=20 plugs, BUR6EQ leading and BUR8EQ trailing a month or so ago.
I = guess I'll=20 have to start burning 100LL to see if it fixes the fouling = problem.
I=20 usually only burn it when I'm travelling and have no other choice, but = don't=20 have any trips planned soon.
For me, it only takes 4 hours of = continuous=20 100LL use to get SAG and fouled leading plugs on the next = takeoff.
Is there=20 any data anywhere that might tell us what temperature BUR6EQ, 7EQ, = 8EQ, and=20 9EQ plugs operate at in an RX-7?

Perry
http://www.ductedfan.com
-----
Regarding=20 spark plug fouling, I knew I had come across an article that indicated = achieving certain minimum temperatures was a key factor in improving=20 (lessening) the fouling of spark plugs.  IT sure seems that = hotter plugs=20 may be part of the answer. 
 
Ed
 
 
Here is the URL for  that article in case = anyone is=20 interested
 

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

Deposits formed between 1000o F and 1300o F are low in volume = and=20 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.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW=
http://www.dmack.net/mazda/index.html
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