X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 04 May 2008 13:01:28 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-galgo.atl.sa.earthlink.net ([209.86.89.61] verified) by logan.com (CommuniGate Pro SMTP 5.2.2) with ESMTP id 2893020 for lml@lancaironline.net; Sun, 04 May 2008 12:30:31 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.61; envelope-from=rpharis@teamimc.com Received: from [71.80.236.247] (helo=ws1) by elasmtp-galgo.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1Jsh5z-0002C4-FO for lml@lancaironline.net; Sun, 04 May 2008 12:29:51 -0400 Reply-To: From: "Rod Pharis" X-Original-To: "'Lancair Mailing List'" Subject: RE: [LML] Re: Lightspeed Plasma III in Performance Engine X-Original-Date: Sun, 4 May 2008 09:30:37 -0700 X-Original-Message-ID: <005b01c8ae04$30259250$6401a8c0@ws1> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_005C_01C8ADC9.83C6BA50" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1914 In-Reply-To: X-ELNK-Trace: 1293b74446918d85d780f4a490ca6956abb457f1b4332f52c0d0ceb5aa13e98ab5e4460e75391d7f350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 71.80.236.247 This is a multi-part message in MIME format. ------=_NextPart_000_005C_01C8ADC9.83C6BA50 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Gentlemen, I recommend using the Magneto ignition for the top plugs, and electronic ignition for the bottom problematic plugs. Also, consider that the smaller gap specified for the mag is to assure good starting characteristics at cranking speed. Mag current output is proportional to RPM. At high RPM mag output is advertised to be greater than an electronic system which oddly has somewhat the opposite phenomenon. Since a dual combo system has the electronic system which is excellent for starting, even with fouled plugs, why not use a wider gap on the mag fired plugs for even better spark at higher RPM. In my humble opinion, having a get-home backup mag system that functions even when the electrical system goes totally dark including inop electrical ignition system in flight is a fantastic advantage!!!!!!! That was the idea behind the mag in a single ignition system in the first place for many decades. Bottom line ... optimize the overall system by using the inherent advantages of both ignition system types, while offsetting the disadvantages of both. Overall ignition system optimization with true redundancy ... what's not to like? Rod Pharis Principal Engineer Northrop Grumman -----Original Message----- From: Lancair Mailing List [mailto:lml@lancaironline.net]On Behalf Of Sky2high@aol.com Sent: Saturday, May 03, 2008 9:13 PM To: lml@lancaironline.net Subject: [LML] Re: Lightspeed Plasma III in Performance Engine Tom, One of the benefits of a stronger spark is the ability to cross a bigger gap. The fire across the bigger gap provides a greater area for ignition of the mixture. Massive electrode spark plugs are of no great benefit (Iridium aircraft fine wire plugs have very small electrodes) in that the weak spark from a mag requires a small gap (.016 to .018) as opposed the .032 gap (.028 to .036, depending) on the Iridium moped plug that I use with the Lightspeed. Remember that massive electrode plugs had to be gapped again after some use because of erosion of the electrode. Another benefit of an Electronic Ignition is the ability to keep the spark going thru maybe 20 or 30 degrees of crank rotation - This allows for a higher probability of ignition of a non-ideal mixture sometime in that span, even if the consequent event timing might suffer a bit. Certain mags (starts with S and ends with K) are known to experience a fair percentage of misfires at the plugs even though the observer can't detect that happening. No point in discussing another archaic device - mechanical points for spark distribution. One of the weaknesses of the LASAR system I once used was that the aircraft plugs had to have the smaller gap, even when electronically fired, because the backup was reversion to magnetos. What is plug fouling - goop buildup that shorts the plug? Is that easier to occur with tight gaps? Or, is it just because the weak spark can't make the jump if the plug is not pristine? If the plug fires every cycle, it should stay clean. Yep, the systems are different. The results are not misleading. Aircraft plugs foul more easily and bottom plugs have a greater opportunity to become fouled. Old Grayhawk Perhaps you detect a bit of disdain for the systems widely used last century. In a message dated 5/1/2008 9:58:06 P.M. Central Daylight Time, tom.gourley@verizon.net writes: Doesn't Lightspeed use an automotive type plug instead of the massive electrode plugs typically used with mags? I was just wondering if the automotive plug is less prone to fouling. The Lightspeed probably does fire through better, but unless the plug configuration is the same on the Lightspeed and the mag it seems like the results could be a little misleading. ---------------------------------------------------------------------------- -- Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. ------=_NextPart_000_005C_01C8ADC9.83C6BA50 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
Gentlemen,
 
I recommend using the Magneto = ignition for=20 the top plugs, and electronic ignition for the bottom problematic plugs. =  Also, consider that the smaller gap specified for the = mag is to=20 assure good starting characteristics at cranking speed.  Mag = current=20 output is proportional to RPM.  At high RPM mag output is = advertised=20 to be greater than an electronic system which oddly has somewhat the = opposite=20 phenomenon.  Since a dual combo system has the electronic system = which is=20 excellent for starting, even with fouled plugs, why not use a wider = gap on=20 the mag fired plugs for even better spark at higher RPM.  In my = humble=20 opinion, having a get-home backup mag system that functions = even when=20 the electrical system goes totally dark including inop electrical = ignition=20 system in flight is a fantastic advantage!!!!!!!  That was the idea = behind=20 the mag in a single ignition system in the first place for many = decades. =20 Bottom line ... optimize the overall system by using the inherent=20 advantages of both ignition system types, while offsetting the = disadvantages of=20 both.  Overall ignition system optimization with true = redundancy ...=20 what's not to like?
 
Rod Pharis
Principal Engineer
Northrop Grumman
 

 -----Original=20 Message-----
From: Lancair Mailing List=20 [mailto:lml@lancaironline.net]On Behalf Of=20 Sky2high@aol.com
Sent: Saturday, May 03, 2008 9:13=20 PM
To: lml@lancaironline.net
Subject: [LML] Re: = Lightspeed=20 Plasma III in Performance Engine

Tom,
 
One of the benefits of a stronger spark is the ability = to cross a=20 bigger gap.  The fire across the bigger gap provides a greater = area for=20 ignition of the mixture.  Massive electrode spark plugs are of no = great=20 benefit (Iridium aircraft fine wire plugs have very small electrodes) = in that=20 the weak spark from a mag requires a small gap (.016 to .018) as = opposed the=20 .032 gap (.028 to .036, depending)  on the Iridium moped = plug that I=20 use with the Lightspeed.  Remember that massive electrode plugs = had to be=20 gapped again after some use because of erosion of the = electrode.
 
Another benefit of an Electronic Ignition is the ability to keep = the=20 spark going thru maybe 20 or 30 degrees of crank rotation - This = allows=20 for a higher probability of ignition of a non-ideal = mixture sometime in=20 that span, even if the consequent event timing might suffer a = bit. =20 Certain mags (starts with S and ends with K) are known to = experience a=20 fair percentage of misfires at the plugs even though the = observer=20 can't detect that happening. 
 
No point in discussing another archaic device - mechanical points = for=20 spark distribution.
 
One of the weaknesses of the LASAR system I once used was = that the=20 aircraft plugs had to have the smaller gap, even when electronically = fired,=20 because the backup was reversion to magnetos. 
 
What is plug fouling - goop buildup that shorts the plug?  = Is that=20 easier to occur with tight gaps? Or, is it just because the = weak=20 spark can't make the jump if the plug is not pristine?  If the = plug fires=20 every cycle, it should stay clean.
 
Yep, the systems are different.  The results are not=20 misleading.  Aircraft plugs foul more easily and bottom plugs = have a=20 greater opportunity to become fouled.
 
Old Grayhawk
Perhaps you detect a bit of disdain for the systems widely used = last=20 century.
 
In a message dated 5/1/2008 9:58:06 P.M. Central Daylight Time,=20 tom.gourley@verizon.net writes:
Doesn't Lightspeed use an automotive type plug instead of the = massive=20 electrode plugs typically used with mags?  I was just wondering = if the=20 automotive plug is less prone to fouling.  The Lightspeed = probably does=20 fire through better, but unless the plug configuration is the same = on the=20 Lightspeed and the mag it seems like the results could be a = little=20 misleading.
 



Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL=20 Food.
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