X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 12 Aug 2006 00:03:28 -0400 Message-ID: X-Original-Return-Path: Received: from imo-d22.mx.aol.com ([205.188.144.208] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with ESMTP id 1319326 for lml@lancaironline.net; Fri, 11 Aug 2006 23:24:10 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.144.208; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-d22.mx.aol.com (mail_out_v38_r7.6.) id q.4bf.570e4e80 (39954) for ; Fri, 11 Aug 2006 23:23:19 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: <4bf.570e4e80.320ea3a7@aol.com> X-Original-Date: Fri, 11 Aug 2006 23:23:19 EDT Subject: Re: [LML] EI timing X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1155352999" X-Mailer: 9.0 Security Edition for Windows sub 5330 X-Spam-Flag: NO -------------------------------1155352999 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 8/11/2006 7:20:55 P.M. Central Standard Time, glcasey@adelphia.net writes: Do you have enough data to allow one to reconstruct the timing algorithm of the Lightspeed system? Gary, Enough to know the normal ranges to expect as I noted. For most of the normal operating range of NA engines that have lower CRs, 25 DBTDC, + or - a bit, is fine (let's say for 65-85% power). EIs will advance the timing when the power is reduced below 75%, frequently this is beneficially seen as the cruise altitude goes higher - 10,000 - 12,000 - 15,000 MSL cruise operation (since the cruise RPM probably is a constant, but the MAP decreases). Have you used a timing light to check the advance of individual cylinders to see if the advance is being computed equally for all? Hey, I only have 4 and two of them have been checked while the other two should match cause of the waste spark logic..... Just curious, as in my system for a 6-cylinder system I see a few unusual indications. For example, one EGT consistently runs higher than the others by maybe 40 degrees, but this is only with the LSE on. Hah. Have you considered a bad ign wire? bad plug? Bad connection to the plug? On the EI side only, of course.... I must assume that if you can turn off the EI, you have some 12th century device backing up the ignition - like a mag. I would expect that a mag-fired half an engine would run totally different than the EI half since the timing and spark energy may be different. When running on the other side (magneto) the temperatures are very uniform. Yes, the F/A mixture and spark may be just right. Perhaps your engine, and the mag spark, fuel supply, and air may be better suited for x degrees BTDC. Perhaps the engine would run better with 2 mags. Perhaps...... I had a failure of the LSE after about 30 where I heard a distinct combustion knock for a few cycles and then the EGT for 2 cylinders from two different channels went up by almost 100. Then all EGT's went up and became uniform - that's when it blew the fuse and I was running on the mag alone. Klaus fixed it just fine and it's been running good since, but that's only been a couple of hours. Another odd thing is that since it was repaired I have 3 cylinders that run about 40 higher than the others, 3,4 and 6. 3 and 4 are the same channel. I'm nervous about the ignition timing not being uniform from cylinder to cylinder. Did Klaus explain what was wrong? Generally, EIs raise CHTs and lower EGTs because of the more complete combustion in the cylinder. There are many possibilities. Anyhow, as I understand it, there are 2 timing events per revolution. The computer calculates when to start firing from those two events. If the events do not always occur because the magnets/sensors are not quite spaced right, the marks can be missed and timing errors can occur. 4 cylinders are so simple............ But, there are other conditions to consider - bad plugs, bad wires, bad connections, bad grounds, etc - on the EI side. The same problems can occur with mags although from your description, the mag seems to be fine. I have no problems running a dual LSE EI with the crank sensor on a lyc engine. It is very difficult to debug ignition problems when there is a mix with EI and mag as the mag (or the EI) may cover the failings of the other. To go down another path, if I over prime my engine, I get a horrendous backfire on start-up because of the EI waste spark system and the fact that even a cylinder due for an exhaust stroke has been filled with fuel - thus a competing explosion (uh, burn). What happens with continuous fuel injection and bad valve overlap? I dunno. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Abnegate Exigencies! -------------------------------1155352999 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 8/11/2006 7:20:55 P.M. Central Standard Time,=20 glcasey@adelphia.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
Do you have enough data= to=20 allow one to reconstruct the timing algorithm of the Lightspeed=20 system?
Gary,
Enough to know the normal ranges to expect as I noted.&n= bsp;=20 For most of the normal operating range of NA engines that have lower CRs, 25= =20 DBTDC, + or - a bit, is fine (let's say for 65-85% power).  EIs wi= ll=20 advance the timing when the power is reduced below 75%, frequently this is=20 beneficially seen as the cruise altitude goes higher - 10,000 - 12,000 -=20 15,000 MSL cruise operation (since the cruise RPM probably is a=20 constant, but the MAP decreases). 
<= FONT=20 size=3D2>  Have you used a timing light to check the advance of indiv= idual=20 cylinders to see if the advance is being computed equally for=20 all?
Hey, I only have 4 and two of them have been checked whi= le the=20 other two should match cause of the waste spark logic.....
<= FONT=20 size=3D2>  Just curious, as in my system for a 6-cylinder system I se= e a=20 few unusual indications.  For example, one EGT consistently runs high= er=20 than the others by maybe 40 degrees, but this is only with the LSE=20 on.
Hah.  Have you considered a bad ign wire?  bad= =20 plug?   Bad connection to the plug?  On the EI side only, of=20 course....  I must assume that if you can turn off the EI, you have som= e=20 12th century device backing up the ignition - like a mag.  I would expe= ct=20 that a mag-fired half an engine would run totally different than the EI= =20 half since the timing and spark energy may be different.
<= FONT=20 size=3D2>  When running on the other side (magneto) the temperatures=20= are=20 very uniform.
Yes, the F/A mixture and spark may be just right.&n= bsp;=20 Perhaps your engine, and the mag spark, fuel supply, and air may be better=20 suited for x degrees BTDC.  Perhaps the engine would run better with 2=20 mags.  Perhaps......
<= FONT=20 size=3D2>  I had a failure of the LSE after about 30 where I heard a=20 distinct combustion knock for a few cycles and then the EGT for 2 cylinder= s=20 from two different channels went up by almost 100.  Then all EGT's we= nt=20 up and became uniform - that's when it blew the fuse and I was running on=20= the=20 mag alone.  Klaus fixed it just fine and it's been running good since= ,=20 but that's only been a couple of hours.  Another odd thing is that si= nce=20 it was repaired I have 3 cylinders that run about 40 higher than the other= s,=20 3,4 and 6.  3 and 4 are the same channel.  I'm nervous about the= =20 ignition timing not being uniform from cylinder to=20 cylinder.
Did Klaus explain what was wrong?  Generally, EIs r= aise=20 CHTs and lower EGTs because of the more complete combustion in the=20 cylinder.  There are many possibilities.  
 
Anyhow, as I understand it, there are 2 timing events pe= r=20 revolution. The computer calculates when to start firing from those two= =20 events.  If the events do not always occur because the magnets/sensors=20= are=20 not quite spaced right,  the marks can be missed and timing errors= can=20 occur.  4 cylinders are so simple............  But, there are othe= r=20 conditions to consider - bad plugs, bad wires, bad connections, bad grounds,= etc=20 - on the EI side.  The same problems can occur with mags although from=20= your=20 description, the mag seems to be fine.
 
I have no problems running a dual LSE EI with the crank=20= sensor=20 on a lyc engine.
 
It is very difficult to debug ignition problems=20 when there is a mix with EI and mag as the mag (or the EI) may cover th= e=20 failings of the other.
 
To go down another path,=20= if I=20 over prime my engine, I get a horrendous backfire on start-up because of the= =20 EI waste spark system and the fact that even a cylinder due for an exha= ust=20 stroke has been filled with fuel - thus a competing explosion (uh,=20 burn).   What happens with continuous fuel injection and bad valve= =20 overlap?  I dunno.
 
   =20
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL=20 (KARR)

Abnegate=20 Exigencies!
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