X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 09 Jan 2008 13:37:15 -0500 Message-ID: X-Original-Return-Path: Received: from imo-d23.mx.aol.com ([205.188.139.137] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2637600 for lml@lancaironline.net; Wed, 09 Jan 2008 10:03:02 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.139.137; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-d23.mx.aol.com (mail_out_v38_r9.3.) id q.d2d.1c864b75 (39331) for ; Wed, 9 Jan 2008 10:02:17 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Wed, 9 Jan 2008 10:02:16 EST Subject: Re: [LML] Re: One mag, One electronic ignition X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1199890936" X-Mailer: Unknown sub 34 X-Spam-Flag: NO -------------------------------1199890936 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Walter, Would you care to give us more complete information? For any given combustion event in a piston 4-cycle engine with certain compression ratio, A/F ratio, fuel octane, # of ignition points,valve count, piston head and chamber shape there is an optimal timing to deliver appropriate pressure during the power stroke. If the timing is changed, the pressure delivery range is changed. Some of the ways to change the timing of the combustion events would be to change the A/F (lean or rich), the octane, and uncommanded ignition events (pre ignition, detonation). If the event is late, the best pressure applied to piston power stroke may be less effective because there is little work for the piston to do. If the event is too early, the pressure may work against the purpose of the engine - the piston may still be on the compression stroke or too early in the power stroke where the rod angle isn't in a position to smoothly deliver the power to the crankshaft, both causing more stress on the engine than is desirable. The fixed timing compromise delivers less than optimal power under conditions outside the engine design range specified by the designer. One of the negative ways to change the timing of the combustion event is to diddle with the mixture so that the engine is operating 20-30F ROP under high power - this can place abnormally high pressure on the piston/chamber and at the wrong time. When all the engine parameters are appropriately controlled, including ignition timing and A/F ratio, the engine can smoothly and efficiently deliver the power within its design and engineering. Thanks for keeping us within the bounds of reason. Scott Krueger Green efficiency thru the use of appropriate timing. If I could only get my stock market timing right........................... . In a message dated 1/9/2008 8:14:42 A.M. Central Standard Time, walter@advancedpilot.com writes: I think what is happening is that the thetaPP is changed less by the loss of the mag than by the loss of the EI. This had little to do with the amount of fuel being burned. BTW, I just looked at the thetaPP data on a set-up where the timing was changed by as little as 2 degrees, advanced. The thetaPP was advanced to 10dATDC and the peak pressures were above 1100 psi. This is not a good thing. You guys do as you please, but that's not something I want to do to my engine. Spark plugs begin to be blasted out of cylinders at 1200psi--by imperical experience. These are observations of hard data. **************Start the year off right. Easy ways to stay in shape. http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489 -------------------------------1199890936 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
Walter,
 
Would you care to give us more complete information?  For any give= n=20 combustion event in a piston 4-cycle engine with certain compression ratio,=20= A/F=20 ratio, fuel octane, # of ignition points,valve count, piston head and=20 chamber shape there is an optimal timing to deliver appropriate pressure dur= ing=20 the power stroke.  If the timing is changed, the pressure=20 delivery range is changed.  Some of the ways to change t= he=20 timing of the combustion events would be to change the A/F (lean or rich), t= he=20 octane, and uncommanded ignition events (pre ignition, detonation).  If= the=20 event is late, the best pressure applied to piston power stroke may be less=20 effective because there is little work for the piston to do.  If the ev= ent=20 is too early, the pressure may work against the purpose of the engine - the=20 piston may still be on the compression stroke or too early in the power stro= ke=20 where the rod angle isn't in a position to smoothly deliver the power to the= =20 crankshaft, both causing more stress on the engine than is desirable.
 
The fixed timing compromise delivers less than optimal power under=20 conditions outside the engine design range specified by the=20 designer.  One of the negative ways to change the  timing of the=20 combustion event is to diddle with the mixture so that the engine is operati= ng=20 20-30F ROP under high power - this can place abnormally high pressure on the= =20 piston/chamber and at the wrong time.
 
When all the engine parameters are appropriately controlled, including=20 ignition timing and A/F ratio, the engine can smoothly and=20 efficiently deliver the power within its design and engineering.
 
Thanks for keeping us within the bounds of reason.
 
Scott Krueger
Green efficiency thru the use of appropriate timing. If I could only ge= t my=20 stock market timing right...........................
 
. 
In a message dated 1/9/2008 8:14:42 A.M. Central Standard Time,=20 walter@advancedpilot.com writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>
I think what is happening is that the thetaPP is changed less by the=20= loss=20 of the mag than by the loss of the EI.  This had little to do with th= e=20 amount of fuel being burned.

BTW, I just looked at the thetaPP data on a set-up where the timing w= as=20 changed by as little as 2 degrees, advanced.  The thetaPP was advance= d to=20 10dATDC and the peak pressures were above 1100 psi.  This is not a go= od=20 thing.  You guys do as you please, but that's not something I want to= do=20 to my engine.  Spark plugs begin to be blasted out of cylinders at=20 1200psi--by imperical experience.

These are observations of hard data.=20
 



<= FONT style=3D"color: black; font: normal 10pt ARIAL, SAN-SERIF;">
Start the year off right. Easy ways to stay in shape in the new year.
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