X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Wed, 16 Aug 2006 02:54:02 -0400 Message-ID: X-Original-Return-Path: Received: from smtp104.sbc.mail.mud.yahoo.com ([68.142.198.203] verified) by logan.com (CommuniGate Pro SMTP 5.1c.3) with SMTP id 1333605 for lml@lancaironline.net; Wed, 16 Aug 2006 02:30:15 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.198.203; envelope-from=elippse@sbcglobal.net Received: (qmail 16901 invoked from network); 15 Aug 2006 21:29:28 -0000 Received: from unknown (HELO Computerroom) (elippse@sbcglobal.net@75.15.127.89 with login) by smtp104.sbc.mail.mud.yahoo.com with SMTP; 15 Aug 2006 21:29:28 -0000 X-Original-Message-ID: <003601c6c0b1$e35b8c90$597f0f4b@Computerroom> From: "Paul Lipps" X-Original-To: "Marv Kaye" Subject: EI HV wiring X-Original-Date: Tue, 15 Aug 2006 14:29:23 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0033_01C6C077.34636C10" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 This is a multi-part message in MIME format. ------=_NextPart_000_0033_01C6C077.34636C10 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable The LSE CDI uses $1.69 NipponDenso automotive sparking plugs and = very high quality, unshielded, silicon HV leads, unlike the shielded = leads used with magnetos. These leads have distributed resistance which = does away with most ignition noise. Usually when there is noise, it is = due to a loose connection, generally at the plug, which results in some = arcing with its attendent arc-discharge radio frequency spectrum. This = noise may also be a sign of arcing through pin-holes in the wiring to = nearby engine structure. Keeping the wires separated from the engine = reduces the voltage pressure across the insulation to mitigate this = punch-through. Wires should be kept clean, too. This goes double for the = "cigarettes" in shielded plugs. They, and the well in the plug, should = be cleaned and never touched by the hands during assembly. Skin oils = from handling can lead to arc-breakdown in the plug, especially at = higher-altitude flying.=20 BTW, a lot of "alternator whine" takes place because of a high = frequency oscillation which occurs when the crossover switching from one = stator winding to another takes place. This may be reduced by placing a = large value electrolytic capacitor on the output, or film capacitors = across each winding to lower its resonant frequency. It's also very = important to provide a wide braid conductor from the alternator ground = terminal to the engine to provide a high conductance path for alternator = currents. Depending on mounting brackets for this pupose is not good = practice. It's also good practice to have a braid from the engine to the = firewall. ------=_NextPart_000_0033_01C6C077.34636C10 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

The LSE CDI uses = $1.69 NipponDenso=20 automotive sparking plugs and very high quality, unshielded, = silicon HV=20 leads, unlike the shielded leads used with magnetos. These leads have=20 distributed resistance which does away with most ignition noise. Usually = when=20 there is noise, it is due to a loose connection, generally at the plug, = which=20 results in some arcing with its attendent arc-discharge radio = frequency=20 spectrum. This noise may also be a sign of arcing through pin-holes = in the=20 wiring to nearby engine structure. Keeping the wires separated from the = engine=20 reduces the voltage pressure across the insulation to mitigate=20 this punch-through. Wires should be kept clean, too. This goes = double for=20 the "cigarettes" in shielded plugs. They, and the well in the = plug, should=20 be cleaned and never touched by the hands during assembly. Skin oils = from=20 handling can lead to arc-breakdown in the plug, especially at = higher-altitude=20 flying.

BTW, a lot of "alternator = whine" takes=20 place because of a high frequency oscillation which occurs when=20 the crossover switching from one stator winding to = another=20 takes place. This may be reduced by placing a large value=20 electrolytic capacitor on the output, or film capacitors across = each=20 winding to lower its resonant frequency. It's also very important to = provide a=20 wide braid conductor from the alternator ground terminal to the = engine to=20 provide a high conductance path for alternator currents. Depending on = mounting=20 brackets for this pupose is not good practice. It's also good = practice to=20 have a braid from the engine to the firewall.

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