X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 04 Jan 2011 14:07:50 -0500 Message-ID: X-Original-Return-Path: Received: from web57507.mail.re1.yahoo.com ([66.196.100.74] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with SMTP id 4663419 for lml@lancaironline.net; Tue, 04 Jan 2011 09:26:14 -0500 Received-SPF: none receiver=logan.com; client-ip=66.196.100.74; envelope-from=casey.gary@yahoo.com Received: (qmail 44850 invoked by uid 60001); 4 Jan 2011 14:25:38 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:References:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=uHyEL0bjCIeSS8QsgDWBaOEHulHFZu4LnpWPEipF//Dh7s1GoAeAYnE1ecn1MVC5yBeLqv1858VkQe0hvwD/ugQ9NNSVjnsmq0XYbrL+VWmR5FXn1rhgOShFX8vOhd89s3p+V+8b8XqM2R++r1QJL0H8zAfY/+BiVlRDwb3038E=; X-Original-Message-ID: <305578.44586.qm@web57507.mail.re1.yahoo.com> X-YMail-OSG: oQLZytMVM1m8SoeeUxtXe.YQkMzIgb1eGYeFf.Gph9BRBgO Hsmoz7P2Ay8lAfLPHPKfRS_8jkhVsT_i6Sh5DnvDuwDZpRBdJ7i3YtUrr4gm QtuO1mwD5WDS8a6lC.T8rDaEDHVJK8hmGkndPHRay93QQq5kfHlhWIkrTtiW V2tdwD8rHgNq7uROKxMQCPBFuX6RyV7HOr62UgjBwRIEwK_O_0o58P5YMlfT yfxon6PinKpotfRPTjtu1RDEVcjL.A7eK7dyyxeTw.ch5Ftenwzv3x6rK_yW OV7L.wqwizNVaskycXzF.tqRJeEbpyp7LXLKall2.bdYHWQAO0vxIoUf7qxq RLgy3HNAx Received: from [97.122.152.1] by web57507.mail.re1.yahoo.com via HTTP; Tue, 04 Jan 2011 06:25:38 PST X-Mailer: YahooMailRC/553 YahooMailWebService/0.8.107.285259 References: X-Original-Date: Tue, 4 Jan 2011 06:25:38 -0800 (PST) From: Gary Casey Subject: Re: spark plug gap X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-1553607818-1294151138=:44586" --0-1553607818-1294151138=:44586 Content-Type: text/plain; charset=us-ascii I'll have to disagree with part of this post: With a standard 6-cylinder magneto system all plugs receive alternating polarity, so rotating the plugs top to bottom or cylinder to cylinder won't do anything (I'm 92.35% sure :-). On a 4-cylinder system the plugs will indeed receive opposite polarities, so rotating the plugs will work if rotated to one step in firing order. On a 6 the mag rotates at 1.5 times engine speed, so each plug will be fired in the opposite polarity every time, so rotating the plugs will have no effect. With most electronic systems, such as the Lightspeed, 2 plugs are fired from each coil, reversing the polarity on half of the plugs, so in this case you could presumably rotate the plugs and gain something. But in this case the plugs would be rotated to a cylinder opposite the firing order, not adjacent. I think the idea of rotating the plugs was to equalize any long-term effects due to temperature and oil consumption variations between cylinders. In that way all plugs will presumably be ready for replacement at the same time. Is that worth the trouble? I don't know, but I don't bother. Gary Casey ES 157, Lyc. 6-cylinder, one mag and one Lightspeed another issue to consider is the direction of electron flow. I was taught t= rotate the plugs on servicing. I was told to advance each plug on reinser=ion one hole. as example from cylinder 1 top to cylinder 3 bottom. then 3 =op to 5 bottom etc.. etc. What does this accomplish? It reverses electr=n flow from center to outer to outer to central thus reducing the wear one=the center. ie it ovals out slower prolonging the life of the plug. Only o=her tip is to be sure and use antisieze (One small drop on threads and a t=rq wrench to accurately tighten to 35 foot lbs. (important) --0-1553607818-1294151138=:44586 Content-Type: text/html; charset=us-ascii
I'll have to disagree with part of this post:  With a standard 6-cylinder magneto system all plugs receive alternating polarity, so rotating the plugs top to bottom or cylinder to cylinder won't do anything (I'm 92.35% sure :-).  On a 4-cylinder system the plugs will indeed receive opposite polarities, so rotating the plugs will work if rotated to one step in firing order.  On a 6 the mag rotates at 1.5 times engine speed, so each plug will be fired in the opposite polarity every time, so rotating the plugs will have no effect.  With most electronic systems, such as the Lightspeed, 2 plugs are fired from each coil, reversing the polarity on half of the plugs, so in this case you could presumably rotate the plugs and gain something.  But in this case the plugs would be rotated to a cylinder opposite the firing order, not adjacent.  I think the idea of rotating the plugs was to equalize any long-term effects due to temperature and oil consumption variations between cylinders.  In that way all plugs will presumably be ready for replacement at the same time.  Is that worth the trouble?  I don't know, but I don't bother.
Gary Casey
ES 157, Lyc. 6-cylinder, one mag and one Lightspeed

another issue to consider is the direction of electron flow. I was taught t= rotate the plugs on servicing. I was told to advance each plug on reinser=ion one hole. as example from cylinder 1 top to cylinder 3 bottom. then 3 =op to 5 bottom etc.. etc.  What does this accomplish? It reverses electr=n flow from center to outer to outer to central thus reducing the wear one=the center. ie it ovals out slower prolonging the life of the plug. Only o=her tip is to be sure and use antisieze (One small drop on threads and a t=rq wrench to accurately tighten to 35 foot lbs. (important)


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