X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [129.116.87.143] (HELO MAIL01.austin.utexas.edu) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 931754 for flyrotary@lancaironline.net; Wed, 18 Jan 2006 15:25:05 -0500 Received-SPF: none receiver=logan.com; client-ip=129.116.87.143; envelope-from=mark.steitle@austin.utexas.edu X-MimeOLE: Produced By Microsoft Exchange V6.5.7226.0 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C61C6D.29C436E3" Subject: RE: [FlyRotary] Re: LS1 Coil Failures Date: Wed, 18 Jan 2006 14:24:20 -0600 Message-ID: <87DBA06C9A5CB84B80439BA09D86E69E036D0A24@MAIL01.austin.utexas.edu> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: LS1 Coil Failures Thread-Index: AcYcZUXViS/Ut70cTw+qZ7LldwkG2AABu2Bw From: "Mark R Steitle" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C61C6D.29C436E3 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Bill, I feel it is a fair assumption that the LS1 coil was never intended to run at 12,000 rpm, as would be the equivalent of what we're doing with the rotary at 6,000 rpm. So, we're clearly operating it outside the design range. Does this shorten their life? Don't know, but Tracy's experience seems to indicate this could be the case. Couple this with other extremes, such as temperature and frequency and they might not be up to the task. =20 =20 The coils on my 126,000 mile LS1 truck are all factory stock. No failures (knock on wood).=20 =20 Mark S. =20 =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of wrjjrs@aol.com Sent: Wednesday, January 18, 2006 1:27 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: LS1 Coil Failures =20 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 =20 -----Original Message----- From: Mark R Steitle To: Rotary motors in aircraft Sent: Wed, 18 Jan 2006 10:51:47 -0600 Subject: [FlyRotary] Re: LS1 Coil Failures Sorry, that's what I get for doing "head math". Anyway, my point is still valid. It fires 8 times more often in the rotary than in the truck/auto. Could the duty-cycle be the culprit? It would be interesting to see the specs on these coils. =20 Mark S.=20 =20 =20 ------_=_NextPart_001_01C61C6D.29C436E3 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Bill,

I feel it is a fair assumption that = the LS1 coil was never intended to run at 12,000 rpm, as would be the = equivalent of what we’re doing with the rotary at 6,000 rpm. So, = we’re clearly operating it outside the design range. Does this shorten = their life? Don’t know, but Tracy’s experience seems to indicate this could be the case. Couple this = with other extremes, such as temperature and frequency and they might not be = up to the task.

The coils on my 126,000 mile LS1 = truck are all factory stock. No failures (knock on wood). =

Mark S. =

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of wrjjrs@aol.com
Sent: Wednesday, January = 18, 2006 1:27 PM
To: Rotary motors in aircraft
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

-----Original Message-----
From: Mark R Steitle <mark.steitle@austin.utexas.edu>
To: Rotary motors in = aircraft <flyrotary@lancaironline.net>
Sent: Wed, 18 Jan 2006 10:51:47 -0600
Subject: [FlyRotary] Re: LS1 Coil Failures

Sorry, that's what I get for doing "head math". Anyway, my point is still valid. It = fires 8 times more often in the rotary than in the truck/auto. Could the duty-cycle be the culprit? It would be interesting to see the = specs on these coils.

Mark S. =

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