X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm6-vm0.bullet.mail.bf1.yahoo.com ([98.139.213.146] verified) by logan.com (CommuniGate Pro SMTP 6.0c2) with ESMTPS id 5801141 for flyrotary@lancaironline.net; Mon, 08 Oct 2012 13:26:27 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.213.146; envelope-from=echristley@att.net Received: from [98.139.212.152] by nm6.bullet.mail.bf1.yahoo.com with NNFMP; 08 Oct 2012 17:25:50 -0000 Received: from [98.139.221.53] by tm9.bullet.mail.bf1.yahoo.com with NNFMP; 08 Oct 2012 17:25:50 -0000 Received: from [127.0.0.1] by smtp106.sbc.mail.bf1.yahoo.com with NNFMP; 08 Oct 2012 17:25:49 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=att.net; s=s1024; t=1349717149; bh=IoQuxYA7yJur3c7s4Ue72FRPEzGtWdo3LHpSh3ksM8A=; h=X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:References:In-Reply-To:Content-Type; b=SQKe1MavHcDtqxsm2gGWKye1BM/LvxQJmiWgHXGqbWrG7PkLzd4ug/rnoT0HWFjblwYZks8zbHOcZ0xcsO4lj8LXYIAQrvLZzF/pzhxrbH3Qg20yZZWTJKuaaezGbRCv20sjDb/zbZodUHDwpe/Hfr+imDf3ylbCqm5XfuI3PdU= X-Yahoo-Newman-Id: 984646.11405.bm@smtp106.sbc.mail.bf1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: AgmYEqkVM1lH9YJCNNOoTuBHE2fLp5jTCg_8VPMZy0ai8Dn .bA_ejpM.ICLPKU.ssNgTYgLs2S.VI2ALxCnnzdWhy40SOi5f3g2HHCWlH0M zCiNtMkXUPj9xRV6xJRaeR6NdREm3w_v8EsYtQi0EWA_ECtOlUxQQ7p0PnaL GoxNpRFaXq1jn2X81WvSDq4Bcor6ghNfDD1pslxIQRbh5q6YSDO_xZIr_qm6 5Ziz6ceOR4H2hLnQodFFivm5K5ScUbMRDJZxfIK2uh.yAvVrg4.7l_MES2jX yMRncgrxJa1NEq.1vqaUTw2Pj3t04gQH9yFp1MmGrn_7q.RYMvFzoXfU6P1C ijEskpVdTeq28PLZCE7_gIk6W8UHDWBMuMVQ_heJz6FMGW4Oj2KUAr_hCeSY K1M9jBCTjBXHxzn12N85IfvmbHbdsWVOBDxVwqRWXceDl X-Yahoo-SMTP: 40RP3pGswBDvPav1a.I8eMv.KS8bdgWBnCloVoKaow-- Received: from [10.62.203.45] (echristley@216.240.30.4 with plain) by smtp106.sbc.mail.bf1.yahoo.com with SMTP; 08 Oct 2012 10:25:49 -0700 PDT Message-ID: <50730C98.9080501@att.net> Date: Mon, 08 Oct 2012 13:25:44 -0400 From: Ernest Chrisltey User-Agent: Mozilla/5.0 (X11; Linux i686; rv:15.0) Gecko/20120907 Thunderbird/15.0.1 MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: colder spark plugs References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------000605030605010105000403" This is a multi-part message in MIME format. --------------000605030605010105000403 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit On 10/08/2012 01:11 PM, Steven W. Boese wrote: > > It's my opinion that heat sinks or sources on the insulator on the > spark plug wire side would have minimal effect on the temperature of > the electrode tip. The proof, of course, would be to try it and see. > I would encourage you to do so. > > I was encouraged by the statement in the link I provided that the temp difference in a hot and cold plug was 10*C to 20*C. My supposition (hard to even call it a hypothesis at this point), is that those experiencing SAG are riding on the ragged edge. Pulling just a little more heat out of the plug would be enough to make them last dependably. How about this for an experimental setup. Fit the engine leading plugs with spark-plug CHT probes. Fashion a heat sink for just one of the LE plugs. Monitor the temps, and cut the plugs open after 25hrs, looking for the deterioration you noted in the first installment. Sounds like an experiment to run, just as soon as I start flying. --------------000605030605010105000403 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit

On 10/08/2012 01:11 PM, Steven W. Boese wrote:

It's my opinion that heat sinks or sources on the insulator on the spark plug wire side would have minimal effect on the temperature of the electrode tip. The proof, of course, would be to try it and see. I would encourage you to do so.

I was encouraged by the statement in the link I provided that the temp difference in a hot and cold plug was 10*C to 20*C. My supposition (hard to even call it a hypothesis at this point), is that those experiencing SAG are riding on the ragged edge. Pulling just a little more heat out of the plug would be enough to make them last dependably.

How about this for an experimental setup. Fit the engine leading plugs with spark-plug CHT probes. Fashion a heat sink for just one of the LE plugs. Monitor the temps, and cut the plugs open after 25hrs, looking for the deterioration you noted in the first installment.

Sounds like an experiment to run, just as soon as I start flying.
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