X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 23 Nov 2011 22:05:32 -0500 Message-ID: X-Original-Return-Path: Received: from nm7.bullet.mail.ac4.yahoo.com ([98.139.52.204] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with SMTP id 5211105 for lml@lancaironline.net; Tue, 22 Nov 2011 23:36:11 -0500 Received-SPF: none receiver=logan.com; client-ip=98.139.52.204; envelope-from=chris_zavatson@yahoo.com Received: from [98.139.52.193] by nm7.bullet.mail.ac4.yahoo.com with NNFMP; 23 Nov 2011 04:35:36 -0000 Received: from [98.139.52.160] by tm6.bullet.mail.ac4.yahoo.com with NNFMP; 23 Nov 2011 04:35:36 -0000 Received: from [127.0.0.1] by omp1043.mail.ac4.yahoo.com with NNFMP; 23 Nov 2011 04:35:36 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 602818.8083.bm@omp1043.mail.ac4.yahoo.com Received: (qmail 71130 invoked by uid 60001); 23 Nov 2011 04:35:36 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=HAuhUoAQsNSA0Nw5+oD/d/rszS7Uz97iowLl5pP9CMOXEzsnP6plq4VLLX/jz7ffIj6G144BmLLDUbGI+ohfkgj1vU3l/FC4B6jS1tiP7T6NiO+rJJYbOy0FVBbvrjVGJKiwlxHHdPlOZw/FTPo2qKcYs1eMcF0h6rAmybeQdVw=; X-YMail-OSG: ZzpOvOUVM1kWjH9i9q3EvcwaVC3k7JnrEFjBpNrYc6oqiEM 79uTDZ4bHlLidXdz.rAb2kMAtAtAjL5zcltApZZwUSaLREPb7V0Au_KMRaNO XsPpPxCAYCZ.L1D5gxpiBMoCgpUbRMWLIQ31rw1jHlyR0a730vkMz5z7MQNw AtrIRY7bR.mVV4KD_jNDcmx4Sj.jS_Nt_I7F5bgGsHlAO7z5u4iKaPHicXcn YwU9NnxhRRXikf9C_JM7lLLLjVVoHPKU8QqY3_Km_n3gZ9bAJQKBqEwLql54 mMlz1dVlkUTH.vMid7ta9_ncmHBGkIMQ1qGHigtbIzR7vuFJq6TlC2grCAWk .wNNeCg_lTky0_8VEr_EsJc8iEjKl0kz8AQz.VP4OoKxWUozUFBLxBeAEqPR C2IPqU0naWgcGJAzvAYvUZCndfw.uvy_BxBqmzIT2NySC3GJS9xjVa728zB8 604ASFFjZh5tG.5npY6BKViZ5_AS6mnLqaoyDADEHFZ0i7eD.jhwCpbY0EEI oZL_hCw-- Received: from [99.137.192.233] by web36903.mail.mud.yahoo.com via HTTP; Tue, 22 Nov 2011 20:35:36 PST X-Mailer: YahooMailWebService/0.8.115.325013 References: X-Original-Message-ID: <1322022936.28313.YahooMailNeo@web36903.mail.mud.yahoo.com> X-Original-Date: Tue, 22 Nov 2011 20:35:36 -0800 (PST) From: Chris Zavatson Reply-To: Chris Zavatson Subject: Re: [LML] Re: E-Mag/P-Mag X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-2114655128-1217238687-1322022936=:28313" ---2114655128-1217238687-1322022936=:28313 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Gary,=0ACould you elaborate on the performance benefits to be expected=A0fr= om advanced spark at altitude.=A0 Efficiency, power, etc.=0A-just curious a= s I spend a lot of time between 13 and 18k with my Slick mags and carb. and= haven't really studied the topic.=0Athanks,=0A=A0=0AChris Zavatson=0AN91CZ= =0A360std=0Awww.N91CZ.net=0A=0AFrom: Gary Casey =0ATo= : lml@lancaironline.net =0ASent: Thursday, November 17, 2011 8:44 AM=0ASubj= ect: [LML] Re: E-Mag/P-Mag=0A=0A=0AIt all depends on the spark advance sche= dule built into the units, and I don't know much about the p-mag. =A0I'm to= ld that at high altitude cruise (low manifold pressures) the Lightspeed wil= l advance the spark by at least 7 degrees over the base timing. =A0That sho= uld (will) give a substantial performance benefit at altitude. =A0Low-eleva= tion takeoffs won't be any different because there is no spark advance chan= ge over a standard mag. =A0All I can tell is that my non-turbocharged ES wi= ll degrade significantly less than a normal plane as the altitude goes up. = =A0It is very happy above 12,000 feet and still has good performance at 17,= 000. =A0Some say 10 to 20 percent, but I'm not sure I buy that. =A0"Up to 1= 0 percent", as the ads say, is certainly believable. =A0If you fly a lot ab= ove 12,000 feet having a system that advances the timing is well worth it, = in my opinion. =A0If you routinely fly at 3,000 feet throttled back to less= than 20 inches manifold pressure you probably wouldn't be subscribed to the Lancair list :-)=0A=0AOn the other = hand, I wouldn't go to the trouble for a turbocharged engine, as the engine= will never - or rarely - operate at low manifold pressure for any length o= f time. =A0The only operational problem with a mag is potential cross-firin= g at high altitude, high boost conditions. =A0So for that reason you might = want a distributorless system(Lightspeed, e-mag, p-mag or whatever), I don'= t know.=0A=0AAgain, the important thing is not so much about how the spark = is formed, but WHEN it fires. =A0Regarding the question from Scott about ef= ficiency or performance - the engine always inhales the same amount of air = and fuel, so the spark advance just increases the power derived - which is = the same as efficiency. =A0More power on the same fuel. =A0The difference i= s greater as the engine is run leaner of peak as well as at high altitude. = =A0Both slow the burn rate, so more advance is welcome.=0A=0AThese comments= apply to any open-loop system. =A0Adaptive systems, such as the PRISM, are= a different story.=0AGary Casey=0A=0A=0A=0A=A0For those using the p-mag.= =A0 Is there any significant increase in fuel efficiency or=0Aincrease in p= erformance noticed?=0A=A0=0AThanks=0AScott Keighan ---2114655128-1217238687-1322022936=:28313 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Gar= y,
Could you elaborate on the performance benefits t= o be expected from advanced = spark at altitude.  Efficiency, power, etc.
<= SPAN style=3D"RIGHT: auto" id=3Dyiv436715057yui_3_2_0_16_1321842896010409>-= just curious as I spend a lot of time between 13 and 18k with my Slick mags= and carb. and haven't really stu= died the topic.
thanks,
 
Chris Zavatson
N91CZ
360std
www.N91CZ.net

From: Gary Casey <casey.gary@yahoo.com>
To: lml@lancaironline.net
Sent: Thursday, November 17, 2011= 8:44 AM
Subject: [LML] = Re: E-Mag/P-Mag

It all depends on the spark advance schedule built into the units, and= I don't know much about the p-mag.  I'm told that at high altitude cr= uise (low manifold pressures) the Lights= peed will advance the spark by at least 7 degrees over the base timi= ng.  That should (will) give a substantial performance benefit at alti= tude.  Low-elevation takeoffs won't be any different because there is = no spark advance change over a standard mag.  All I can tell is that m= y non-turbocharged ES will degrade significantly less than a normal plane a= s the altitude goes up.  It is very happy above 12,000 feet and still = has good performance at 17,000.  Some say 10 to 20 percent, but I'm no= t sure I buy that.  "Up to 10 percent", as the ads say, is certainly b= elievable.  If you fly a lot above 12,000 feet having a system that ad= vances the timing is well worth it, in my opinion.  If you routinely fly at 3,000 feet throttled back to less than 20 inches manifold= pressure you probably wouldn't be subscribed to the Lancair list :-)

On the other hand, I wouldn't go to the trouble for a turbocharged eng= ine, as the engine will never - or rarely - operate at low manifold pressur= e for any length of time.  The only operational problem with a mag is = potential cross-firing at high altitude, high boost conditions.  So fo= r that reason you might want a distribut= orless system(Lightspeed, = e-mag, p-mag or whatever), I don't know.

Again, the important thing is not so much about how the spark is forme= d, but WHEN it fires.  Regarding the question from Scott about efficie= ncy or performance - the engine always inhales the same amount of air and f= uel, so the spark advance just increases the power derived - which is the s= ame as efficiency.  More power on the same fuel.  The difference = is greater as the engine is run leaner of peak as well as at high altitude.=  Both slow the burn rate, so more advance is welcome.

These comments apply to any open-loop system.  Adaptive systems, = such as the PRISM, are a different story.
Gary Casey


 For those using the p-mag.  Is there any sign= ificant increase in fuel efficiency or
increase in performance noticed?<= BR> 
Thanks
Scott Keighan


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