X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.12.137.4] (HELO imo-m23.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 931722 for flyrotary@lancaironline.net; Wed, 18 Jan 2006 14:50:26 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.4; envelope-from=WRJJRS@aol.com Received: from WRJJRS@aol.com by imo-m23.mx.aol.com (mail_out_v38_r6.3.) id q.23d.569e1d4 (15862) for ; Wed, 18 Jan 2006 14:49:36 -0500 (EST) Received: from FWM-M20 (fwm-m20.webmail.aol.com [64.12.168.84]) by air-id06.mx.aol.com (v108_r1_b1.2) with ESMTP id MAILINID61-3df643ce9bce2f7; Wed, 18 Jan 2006 14:49:35 -0500 Date: Wed, 18 Jan 2006 14:49:33 -0500 Message-Id: <8C7EA7F7090378C-B18-17CE@FWM-M20.sysops.aol.com> From: wrjjrs@aol.com References: Received: from 66.127.99.234 by FWM-M20.sysops.aol.com (64.12.168.84) with HTTP (WebMailUI); Wed, 18 Jan 2006 14:49:33 -0500 X-MB-Message-Source: WebUI X-MB-Message-Type: User In-Reply-To: X-Mailer: AOL WebMail 15106 Subject: Re: [FlyRotary] Re: LS1 Coil Failures Content-Type: multipart/alternative; boundary="--------MailBlocks_8C7EA7F7086AE28_B18_1797_FWM-M20.sysops.aol.com" MIME-Version: 1.0 To: flyrotary@lancaironline.net X-AOL-IP: 64.12.168.84 X-Spam-Flag: NO ----------MailBlocks_8C7EA7F7086AE28_B18_1797_FWM-M20.sysops.aol.com Content-Type: text/plain; charset="us-ascii" Point well taken Al, We do see these type of coils attached to the valve cover of cars. As was mentioned directly above the exhaust manifold! In slow/no moving trafic this must cause considerable environmental heating. The concern of the coil being fired more often is important and should be considered. The solution is simple just mount the coils away from the engine and use a cool box. The question is how many of these things HAVE failed? A single failure could be a result of a failure anywhere in the manufacturing process. Put more simply, the thing might have been going to fail anyway. How many people have had a LS-1 coil fail in the group? Bill Jepson -----Original Message----- From: Al Gietzen To: Rotary motors in aircraft Sent: Wed, 18 Jan 2006 11:38:10 -0800 Subject: [FlyRotary] Re: LS1 Coil Failures Mark, There may well be a duty cycle problem, but I doubt it. Older ignitions used a single coil of similar type firing all 8 cylinders. I would be more likely to suggest it was a "bathtub failure curve" failure of the solid state "trigger" circuit. Bill Jepson Ah-h-h; and why would duty cycle not have an effect on temperature and failure rate of the ?trigger? circuit? The solid state components do dissipate some heat, and the more cycles, the more heat and other effects leading to failure. Al G ----------MailBlocks_8C7EA7F7086AE28_B18_1797_FWM-M20.sysops.aol.com Content-Type: text/html; charset="us-ascii"

Point well taken Al,

We do see these type of coils attached to the valve cover of cars. As was mentioned directly above the exhaust manifold! In slow/no moving trafic this must cause considerable environmental heating. The concern of the coil being fired more often is important and should be considered. The solution is simple just mount the coils away from the engine and use a cool box. The question is how many of these things HAVE failed? A single failure could be a result of a failure anywhere in the manufacturing process. Put more simply, the thing might have been going to fail anyway. How many people have had a LS-1 coil fail in the group?

Bill Jepson

-----Original Message-----
From: Al Gietzen <ALVentures@cox.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, 18 Jan 2006 11:38:10 -0800
Subject: [FlyRotary] Re: LS1 Coil Failures

Mark,

There may well be a duty cycle problem, but I doubt it. Older ignitions used a single coil of similar type firing all 8 cylinders. I would be more likely to suggest it was a "bathtub failure curve" failure of the solid state "trigger" circuit.

Bill Jepson

Ah-h-h; and why would duty cycle not have an effect on temperature and failure rate of the ?trigger? circuit? The solid state components do dissipate some heat, and the more cycles, the more heat and other effects leading to failure.

Al G

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