X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from willowsprings.uwyo.edu ([129.72.10.31] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTPS id 3992006 for flyrotary@lancaironline.net; Thu, 26 Nov 2009 11:59:22 -0500 Received-SPF: none receiver=logan.com; client-ip=129.72.10.31; envelope-from=SBoese@uwyo.edu Received: from ponyexpress-ht1.uwyo.edu (ponyexpress-ht1.uwyo.edu [10.84.60.208]) by willowsprings.uwyo.edu (8.14.2/8.14.2) with ESMTP id nAQGwjdS020496 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO) for ; Thu, 26 Nov 2009 09:58:45 -0700 (MST) (envelope-from SBoese@uwyo.edu) Received: from ponyexpress-mb5.uwyo.edu ([fe80::9c55:bfd9:7a5b:5a4]) by ponyexpress-ht1 ([10.84.60.208]) with mapi; Thu, 26 Nov 2009 09:58:45 -0700 From: "Steven W. Boese" To: Rotary motors in aircraft Date: Thu, 26 Nov 2009 09:58:44 -0700 Subject: RE: [FlyRotary] Re: Ground isn't ground Thread-Topic: [FlyRotary] Re: Ground isn't ground Thread-Index: AcpurMzQ4s31DQk4RWOzsWIUnQJiZQAC7Yzx Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 If you refer to archive message# 49009 on Nov 8, traces of coil control and= CAS signals are there. I have 2 EC2's driving LS1 coils and all 4 control= lers show the same behavior. This affects spark intensity and timing only = below about 1200 RPM and is only a factor on start up or very low idle. Ab= ove the transition at about 1200 PM, dwell time are consistently in the ran= ge of 4 to 5 ms regardless of the mode 8 setting or RPM. Steve Boese =20 ________________________________________ From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of = Tracy Crook [tracy@rotaryaviation.com] Sent: Thursday, November 26, 2009 8:25 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Ground isn't ground I haven't noticed the spark being that weak during cranking but haven't mad= e any specific measurements of it either. The spark will be weaker due to t= he voltage drop of the battery if nothing else, even if there is no drop in= the wiring. Dwell on the EC2/3 during cranking (below 400 rpm) depends on the version/e= ngine type but on the 20B it should be well beyond the minimum saturation t= ime of the coils. My concerns have been that it is too long during cranki= ng rather than too short. Dwell time longer than required for coil saturat= ion adds nothing to spark strength but does heat up the electronics in the = igniter. IIRC, Steve is using the RX-7 type igniters which is a different situation.= They control their own dwell internally (after the first cycle) and the E= C2 only controls ignition time with the negative edge of the control pulse. Tracy