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 3992414 for flyrotary@lancaironline.net; Thu, 26 Nov 2009 22:06:34 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.221.174; envelope-from=rwstracy@gmail.com Received: by qyk4 with SMTP id 4so489316qyk.7 for ; Thu, 26 Nov 2009 19:06:00 -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=81an6ViPUCAXTaswAEXXHUyhpkpgi02bw2gllUWR0RM=; b=J0UApl+VjkvGaLGiN1jcDNNv3hfxMv9UmAR5Kgp9QF88qTbSupoAanje2dlB6lPVp+ /cK5pejzdW48sNb4ZUuDn71EYXHZhEWx+B0ikDCyOBxsvzs55u3mNVTRu63nf2s1jFNa G9LCZnj+HMaQFmGXA/5FbIraRyliSO9aPMiLw= 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=r2IOzRyq0TiEPSFn1Kq0sUub3Xg5Jb8xzGxi+gKJhvq2fCR1YDTrS9mjTYOOa52a4N 8VLDMPdc8i8+psi6BrSSa+T6EEHfJm4toSGXdWugrK95p4Vs7AbDqXZIUyC7DjM7/jon 75yIfz+XDHhcOewsQvO5KkhW63CAXQZ7EdbN8= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.224.53.15 with SMTP id k15mr250619qag.44.1259291160037; Thu, 26 Nov 2009 19:06:00 -0800 (PST) In-Reply-To: References: Date: Thu, 26 Nov 2009 22:05:59 -0500 X-Google-Sender-Auth: 15e152a28be93aad Message-ID: <1b4b137c0911261905s3396adfds450983971d9a8a14@mail.gmail.com> Subject: Re: [FlyRotary] Re: Ground isn't ground From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=00c09f923198434aa4047951928d --00c09f923198434aa4047951928d Content-Type: text/plain; charset=ISO-8859-1 Steve, I was looking at the wrong image (the one you sent of the CAS & dwell at cranking speed of ~150 rpm.) . I must have missed this other one when you posted it. I'll take a look at the 1200 rpm dwell behavior again. I never noticed that. Possibly because 1200 is well above cranking speed but below my idle speed of 1600 rpm. Do you recall the date of your last EC2 update? The low rpm dwell algorithm has changed a few times. Tracy On Thu, Nov 26, 2009 at 8:04 PM, Steven W. Boese wrote: > First let me echo the wish expressed by Tracy and others that a Happy > Thanksgiving be enjoyed by all. > > It is a privilege to participate in this list where the messages are always > positive in nature. > > I am obviously not presenting the data from my EC2's concerning the coil > control signals in such a way as to clearly show my concerns. In the > labeled image referred to previously, a dwell time of <0.3 ms is shown below > the "ignition threshold" (on the left) and above this threshold, a dwell > time of 4.3 ms is shown on the right. In the unlabled image, a dwell time > of 106 ms is shown below the threshold (on the left) and a dwell time of 4-5 > ms is shown on the right. I don't see a dwell signal in the 16 ms > neighborhood. > > I agree that dwell times longer than longer than 16 ms would have no > benefit. This is because the coil modules limit the dwell time to about 8 > ms internally and generate a good spark at that time regardless of a coil > control signal that is still high. It makes sense for the coil module to do > this to limit the internally generated heat. > > An image is attached which shows the coil control signals obtained using > the EC2's ignition diagnostic function at the top. Shown at the bottom are > the CAS signal and #1 rotor leading coil control signal obtained at about > 1200 RPM using a mode 8 setting of 8 degrees advanced. The time scales of > the top and bottom plots are as close as I could make them. Hopefully, this > attachment shows what I am referring to as "short" dwell times which result > in very weak sparks. > > Finally let me stress that once the engine is started and running, my EC2's > have never failed to get me home. > > Steve Boese > > > > ________________________________________ > From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of > Tracy Crook [tracy@rotaryaviation.com] > Sent: Thursday, November 26, 2009 2:09 PM > To: Rotary motors in aircraft > Subject: [FlyRotary] Re: Ground isn't ground > > 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 SBoese@uwyo.edu>> 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 > > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > --00c09f923198434aa4047951928d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Steve, I was looking at the wrong image (the one you sent of the CAS & = dwell at cranking speed of ~150 rpm.)=A0 .=A0 I must have missed this other= one when you posted it.=A0=A0 I'll take a look at the 1200 rpm dwell b= ehavior again.=A0=A0 I never noticed that.=A0 Possibly because 1200 is well= above cranking speed but below my idle speed of 1600 rpm.

Do you recall the date of your last EC2 update?=A0 The low rpm dwell al= gorithm has changed a few times.

Tracy

On Thu, Nov 26, 2009 at 8:04 PM, Steven W. Boese <= ;SBoese@uwyo.edu> wrote:
First let me echo= the wish expressed by Tracy and others that a Happy Thanksgiving be enjoye= d by all.

It is a privilege to participate in this list where the messages are always= positive in nature.

I am obviously not presenting the data from my EC2's concerning the coi= l control signals in such a way as to clearly show my concerns. =A0 In the = labeled image referred to previously, a dwell time of <0.3 ms is shown b= elow the "ignition threshold" (on the left) =A0and =A0above this = threshold, a dwell time of 4.3 ms is shown on the right. =A0In the unlabled= image, a dwell time of 106 ms is shown below the threshold (on the left) a= nd a dwell time of 4-5 ms is shown on the right. =A0I don't see a dwell= signal in the 16 ms neighborhood.

I agree that dwell times longer than longer than 16 ms would have no benefi= t. =A0This is because the coil modules limit the dwell time to about 8 ms i= nternally and generate a good spark at that time regardless of a coil contr= ol signal that is still high. =A0It makes sense for the coil module to do t= his to limit the internally generated heat.

An image is attached which shows the coil control signals obtained using th= e EC2's ignition diagnostic function at the top. =A0Shown at the bottom= are the CAS signal and #1 rotor leading coil control signal obtained at ab= out 1200 RPM using a mode 8 setting of 8 degrees advanced. =A0The time scal= es of the top and bottom plots are as close as I could make them. =A0Hopefu= lly, this attachment shows what I am referring to as "short" dwel= l times which result in very weak sparks.

Finally let me stress that once the engine is started and running, my EC2&#= 39;s have never failed to get me home.

Steve Boese



________________________________________
From: Rotary motors in aircraft [flyrotary@lancaironline.net] On Behalf Of Tracy Crook [tracy@rotaryaviation.com]
Sent: Thursday, November 26, 2009 2:09 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Ground isn't ground

Good info Steve, guess I didn't remember the co= ils you were using correctly.

In any case,
Best I could measure on your photo, the EC2 was delivering about 16 ms of d= well which is way more than enough to fully saturate the coils. =A0I would = conclude from this that there is nothing to be gained from increasing dwell= at cranking speed. =A0 For reference, the dwell during coil test is around= 5 ms.

Tracy =A0(Happy Thanksgiving Day to all)



On Thu, Nov 26, 2009 at 11:58 AM, S= teven W. Boese <SBoese@uwyo.edu&l= t;mailto:SBoese@uwyo.edu>> wro= te:

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




--
Homepage: =A0http:/= /www.flyrotary.com/
Archive and UnSub: =A0 http://mail.lancaironline.net:81/lists= /flyrotary/List.html


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