X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 04 Jan 2008 19:55:41 -0500 Message-ID: X-Original-Return-Path: Received: from elasmtp-mealy.atl.sa.earthlink.net ([209.86.89.69] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2630783 for lml@lancaironline.net; Fri, 04 Jan 2008 10:08:26 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.69; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=YN/2gDWsGaEtRUU7rD6mfBHPxOZJxSFyPUWSqt+gbrlk/MIEYgps8JaFtpQgT21z; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.89] (helo=ccaselt2) by elasmtp-mealy.atl.sa.earthlink.net with asmtp (Exim 4.34) id 1JAo9C-0007xj-0d for lml@lancaironline.net; Fri, 04 Jan 2008 10:07:46 -0500 X-Original-Message-ID: <051f01c84ee3$90135d30$0202a8c0@nvidia.com> From: "Colyn Case on earthlink" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] One mag, One electronic ignition X-Original-Date: Fri, 4 Jan 2008 10:07:45 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_051C_01C84EB9.A68CC9E0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da9407e0b51b9539655bc340cce0545b4d340350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.89 This is a multi-part message in MIME format. ------=_NextPart_000_051C_01C84EB9.A68CC9E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [LML] One mag, One electronic ignitionHey Doug, you went and changed the subject line.....bad news for those of us = that sort by subject. anyway, my $.02 - more power: in theory you can set up a mag engine to get the same = power in one config. In other words, if the main thing you care about = is cruise, you could set your spark timing to be just right for your = favorite mixture and your favorite rpm. - engine damage. lacking variable timing, all you have is mixture to = protect your engine from harm. With fixed timing it's clear what to do = (e.g. if you take APS). With some unknown timing curve in an electronic = ignition box, I don't know what to do. I asked Klaus what his timing = curve was really and he just blew me off. Lacking that information, I = wasn't willing to have his box in my airplane. - open loop control systems. As far as I know, all electronic ignition = systems that are for sale are open loop. ....meaning they determine = timing based on control inputs but don't actually have any sensors in = the cylinder to determine what is happening. PRISM's approach is = radically different in that it measures the angle of peak pressure and = tries to keep it in a very narrow range no matter what you do to the = engine controls. As a result, you can run right at peak, ROP, LOP, = whatever you want. ...and this has obvious advantages both in terms of = power and engine longevity. Unfortunately PRISM isn't for sale at this = point. - one mag and one electronic. Seems plausible but you lose timing = control if you leave the mag on. If I were going to do this I would = want to run most of the time with the mag off I think.....and that would = mean different timing curves. I don't know if any of the electronic = setups deal with that properly or not. - backup power. GAMI does have a supplenator for sale. It's a = self-exciting replacement for your backup alternator with automatic load = shedding. I'm also intrigued with the e-mag idea. conclusion: I decided to stick with 2 mags until I see a) a seriously = bullet proof backup power solution. b) a closed loop ignition system = or an open loop system that is clearly documented and backed up by test = stand analysis. For what I care about I can get most of what I want = by cruising LOP and just using a lot of gas in max power configurations. = A good electronic system would allow cruising AT PEAK without damaging = the engine and that would mean some incremental power. =20 Colyn ------=_NextPart_000_051C_01C84EB9.A68CC9E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable [LML] One mag, One electronic ignition
Hey Doug,
 
    you went and changed = the subject=20 line.....bad news for those of us that sort by subject.  anyway, my = $.02
 
- more power:  in theory you can = set up a mag=20 engine to get the same power in one config.   In = other words,=20 if the main thing you care about is cruise, you could set your spark = timing to=20 be just right for your favorite mixture and your favorite = rpm.
 
- engine damage.  lacking variable = timing, all=20 you have is mixture to protect your engine from harm.  With fixed = timing=20 it's clear what to do (e.g. if you take APS).  With some unknown = timing=20 curve in an electronic ignition box, I don't know what to do.  I = asked=20 Klaus what his timing curve was really and he just blew me = off.  =20 Lacking that information, I wasn't willing to have his box in my=20 airplane.
 
- open loop control = systems.   As far as=20 I know, all electronic ignition systems that are for sale are open=20 loop.   ....meaning they determine timing based on control = inputs but=20 don't actually have any sensors in the cylinder to determine what is=20 happening.   PRISM's approach is radically different in that = it=20 measures the angle of peak pressure and tries to keep it in a very = narrow range=20 no matter what you do to the engine controls.   As a result, = you can=20 run right at peak, ROP, LOP, whatever you want.  ...and this has = obvious=20 advantages both in terms of power and engine longevity.  =20 Unfortunately PRISM isn't for sale at this point.
 
- one mag and one = electronic.   Seems=20 plausible but you lose timing control if you leave the mag = on.   =20 If I were going to do this I would want to run most of the time with the = mag off=20 I think.....and that would mean different timing = curves.    I=20 don't know if any of the electronic setups deal with that properly or=20 not.
 
- backup power.   GAMI does = have a=20 supplenator for sale.  It's a self-exciting replacement for your = backup=20 alternator with automatic load shedding.   I'm also intrigued = with the=20 e-mag idea.
 
conclusion:  I decided to = stick with 2=20 mags until I see a) a seriously bullet proof backup power = solution.  =20 b) a closed loop ignition system or an open loop system that is clearly=20 documented and backed up by test stand analysis.    For = what I=20 care about I can get most of what I want by cruising LOP and just using = a lot of=20 gas in max power configurations.   A good electronic system = would=20 allow cruising AT PEAK without damaging the engine and that would mean = some=20 incremental power.  
 
Colyn
 
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