X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 28 Apr 2006 21:25:24 -0400 Message-ID: X-Original-Return-Path: Received: from smtp112.sbc.mail.mud.yahoo.com ([68.142.198.211] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with SMTP id 1084118 for lml@lancaironline.net; Fri, 28 Apr 2006 02:56:09 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.198.211; envelope-from=elippse@sbcglobal.net Received: (qmail 38709 invoked from network); 28 Apr 2006 06:55:24 -0000 Received: from unknown (HELO Computerroom) (elippse@sbcglobal.net@70.237.146.93 with login) by smtp112.sbc.mail.mud.yahoo.com with SMTP; 28 Apr 2006 06:55:23 -0000 X-Original-Message-ID: <000501c66a90$be861150$5d92ed46@Computerroom> From: "Paul Lipps" X-Original-To: "Marv Kaye" Subject: Detonation & pre-ignition X-Original-Date: Thu, 27 Apr 2006 23:55:29 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0002_01C66A56.1045A810" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 This is a multi-part message in MIME format. ------=_NextPart_000_0002_01C66A56.1045A810 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Contact! magazine, issue #54, had an excellent article on detonation, = often called "pinging", and pre-ignition. He states that pre-ignition = can actually occur as much as 90 degrees before TDC, which is why the = piston gets eroded or holed in just a few revolutions. The piston is = being pushed up against the pressure and heat of the burning charge. An = engine can be run continuously while pinging, and it will only cause = some pitting on the top of the piston. I used to adjust the timing on my = cars so that I got a slight ping under a load. Where detonation can be = harmful is if it causes a hot spot to develop which in turn can cause = pre-ignition. Back issues of #54 are available at = www.contactmagazine.com . ISSUE 54 =20 a.. Engine basics: Detonation and Pre-ignition GM engine designer = Allen Cline warns of catastrophic engine failure modes inherent in = modern high output engines (>.5 HP/in3). =20 ------=_NextPart_000_0002_01C66A56.1045A810 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Contact! magazine, issue #54, had an = excellent=20 article on detonation, often called "pinging", and pre-ignition. He = states that=20 pre-ignition can actually occur as much as 90 degrees before TDC, which = is why=20 the piston gets eroded or holed in just a few revolutions. The piston is = being=20 pushed up against the pressure and heat of the burning charge. An engine = can be=20 run continuously while pinging, and it will only cause some pitting = on the=20 top of the piston. I used to adjust the timing on my cars so that I got = a slight=20 ping under a load. Where detonation can be harmful is if it causes = a hot=20 spot to develop which in turn can cause pre-ignition. Back issues of #54 = are available at www.contactmagazine.com=20 .
 
ISSUE 54 
  • Engine basics: Detonation and=20 Pre-ignition GM engine designer = Allen Cline=20 warns of catastrophic engine failure modes inherent in modern high = output=20 engines (>.5 HP/in3). 
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