Mailing List flyrotary@lancaironline.net Message #3176
From: Tracy Crook <lors01@msn.com>
Subject: Re: [FlyRotary] Re: EC2 in-flight timing adjustment.
Date: Sun, 21 Sep 2003 15:50:03 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Yes, Ed summarized it very well.   Think of the 5.625 degrees as 'Vacuum advance' on the old distributors. 
 
Tommy also asked if best power timing was the same as best economy timing.   The manifold pressure advance was an attempt to achieve both.  I think its pretty close.  If anyone wants to prove other wise, I would welcome the info and will promptly incorporate it into the EC2 software.
 
Tracy
 
----- Original Message -----
Sent: Sunday, September 21, 2003 1:17 PM
Subject: [FlyRotary] Re: EC2 in-flight timing adjustment.

Not Tracy, although sometimes I fool folks when I don't have a mustach {:>)
 
However, I think I can answer your question, Tommy.
 
What Tracy is saying is that he is playing with his timing advance/retard.  Normally if you set the static timing like Tracy says to do in his instructions, you would have the plug firing at between 20-23 degrees Before Top Dead Center at any rpm greater that 3600 rpm. (Remember, Tracy's system only retards the timing, it does not ADVANCE it.  When you think you are advancing the ignition time what you are really doing is dialing in LESS retard.  That is why setting the static timing per Tracy's instructions is important because what you are really setting -is the maximum advance for the system through the physical adjustment of the crank angle sensor.  Then when you adjust the timing you are backing off of that advance.  In other words, your maximum advance on the controller is actually the minimum Retard position)  However, if you do what Tracy mentions in the first, clipped part of that sentence, then your timing above 3600 rpm would be closer to 20-23+5.625 or timing may range from 25.625 to 28.625 BTDC.
 
Ed Anderson
----- Original Message -----
Sent: Sunday, September 21, 2003 12:26 PM
Subject: [FlyRotary] Re: EC2 in-flight timing adjustment.

Tracy, 
Would you further explain this line?
 
 
"....  The timing is advanced by 5.625 degrees more than nominal timing which is typically 20 - 23 deg BTDC at rpm > 3600. "
Tracy
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster