X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-qy0-f174.google.com ([209.85.221.174] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTP id 3992188 for flyrotary@lancaironline.net; Thu, 26 Nov 2009 16:10:05 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.221.174; envelope-from=rwstracy@gmail.com Received: by qyk4 with SMTP id 4so416912qyk.7 for ; Thu, 26 Nov 2009 13:09:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=Ik37iirTgZdQ7xMnUIF8raoznnxj5haYO1oWhuydUus=; b=VvOb9dd1XHu5VkwNVQHZu5eRwvVu2q1twAf7nz4u0Zzdw+rWqaJlAHVOHqbcDRps+c 6OWZ5IK60vqaCBFsn8PqACinz3NfWqW6JXWmobZ9/rG6bXEfYvN0k28+8ltcAuaN0jdz BtQJG5CErRgloRwtfxr3Qm4zdA2+0giUhtqkE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=ag+mP7vN6kAxwoZwJZ1CdSODgFq2y12w6o1iQdyPD00PSsJ42ITUs/tkHXaVPSRpyW rmnTt0qRrXxUemZYAD7hEKbKRSo4MMvplQEVeCoF6/jgJ9VMkUet/ZD9+aNaCuwtBrkr A9eiVp8q5HsihWzRtinjPgGH68wZ/1gfo1YpE= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.224.59.130 with SMTP id l2mr115059qah.73.1259269770325; Thu, 26 Nov 2009 13:09:30 -0800 (PST) In-Reply-To: References: Date: Thu, 26 Nov 2009 16:09:30 -0500 X-Google-Sender-Auth: cafa279796cc615e Message-ID: <1b4b137c0911261309y60838410k761c91f5c19c5b80@mail.gmail.com> Subject: Re: [FlyRotary] Re: Ground isn't ground From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=00c09f99deaf562f1f04794c9788 --00c09f99deaf562f1f04794c9788 Content-Type: text/plain; charset=ISO-8859-1 Good info Steve, guess I didn't remember the coils you were using correctly. In any case, Best I could measure on your photo, the EC2 was delivering about 16 ms of dwell which is way more than enough to fully saturate the coils. I would conclude from this that there is nothing to be gained from increasing dwell at cranking speed. For reference, the dwell during coil test is around 5 ms. Tracy (Happy Thanksgiving Day to all) On Thu, Nov 26, 2009 at 11:58 AM, Steven W. Boese wrote: > > 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 > controllers 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. > Above the transition at about 1200 PM, dwell time are consistently in the > range of 4 to 5 ms regardless of the mode 8 setting or RPM. > > Steve Boese > > > ________________________________________ > 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 > made any specific measurements of it either. The spark will be weaker due to > the 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/engine type but on the 20B it should be well beyond the minimum > saturation time of the coils. My concerns have been that it is too long > during cranking rather than too short. Dwell time longer than required for > coil saturation 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 EC2 > only controls ignition time with the negative edge of the control pulse. > > Tracy > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > --00c09f99deaf562f1f04794c9788 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Good info Steve, guess I didn't remember the coils you were using corre= ctly.=A0

In any case,
Best I could measure on your photo, the EC= 2 was delivering about 16 ms of dwell which is way more than enough to full= y saturate the coils.=A0 I would conclude from this that there is nothing t= o be gained from increasing dwell at cranking speed.=A0=A0 For reference, t= he dwell during coil test is around 5 ms.

Tracy=A0 (Happy Thanksgiving Day to all)



On Thu, Nov 26, 2009 at 11:58 AM, Steven W. Boese <SBoese@uwyo.edu> = wrote:

If you refer to archive message# 49009 on Nov 8, traces of coil control and= CAS signals are there. =A0I have 2 EC2's driving LS1 coils and all 4 c= ontrollers show the same behavior. =A0This affects spark intensity and timi= ng only below about 1200 RPM and is only a factor on start up or very low i= dle. =A0Above the transition at about 1200 PM, dwell time are consistently = in the range of 4 to 5 ms regardless of the mode 8 setting or RPM.

Steve Boese


________________________________________
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&#= 39;t made any specific measurements of it either. The spark will be weaker = due to the 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. =A0 My concerns have been that it is too long during cran= king rather than too short. =A0Dwell time longer than required for coil sat= uration 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.= =A0They control their own dwell internally (after the first cycle) and the= EC2 only controls ignition time with the negative edge of the control puls= e.

Tracy



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Homepage: =A0http:/= /www.flyrotary.com/
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