X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost02.isp.att.net ([204.127.217.102] verified) by logan.com (CommuniGate Pro SMTP 5.4.0) with ESMTP id 5044688 for flyrotary@lancaironline.net; Thu, 07 Jul 2011 09:29:50 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.217.102; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-98-85-108-10.mco.bellsouth.net[98.85.108.10]) by isp.att.net (frfwmhc02) with SMTP id <20110707132913H0200cficme>; Thu, 7 Jul 2011 13:29:14 +0000 X-Originating-IP: [98.85.108.10] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: fuel flow Date: Thu, 7 Jul 2011 09:29:16 -0400 Message-ID: <43CB11E1BA5E46DCB1BA9020364216CB@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0013_01CC3C88.579F0580" X-Mailer: Microsoft Office Outlook 11 Thread-Index: Acw8nRUxwpaIPjCPQBaZDd1PYb1IjgAC6PlQ X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 This is a multi-part message in MIME format. ------=_NextPart_000_0013_01CC3C88.579F0580 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Ernest, Someone could correct me, but I don't think the EC-2 moves the ignition timing a whole lot. Since you are inventing this tuning for your system, why don't you set your timing at a constant spot, say 20 degrees like Lynn suggested, and then tune the fuel map. After you get the fuel pretty good, then you can go back and try and improve it with the ignition. Then do another pass with the fuel. You should be there at that point.well you can always hope! You didn't say anything about the fire extinguisher..that could be more important than the tuning! If you think your wife was upset over the exhaust smell, wait till you smoke damage her new wallpaper! :>) Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ernest Christley Sent: Thursday, July 07, 2011 7:57 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel flow On 07/07/2011 06:51 AM, Lehanover@aol.com wrote: I suggest adding a bunch of fuel first. Then lean back to take off power at about 50 to 100 degrees rich of peak power/EGT, or under 1600 degrees. Or F/A in the 12s. We have people in charge of warping apex seals. You do not need to cover that again. Roger that. The issue is knowing what number to put in to get bunch-o-fuel. I thought my VE numbers set to over 100 would be good. The tuning software came back at me with suggestions of 175 after the short power run. I sense a lack of check list. I detect more than one change at a time. (a dyno room violation) That sixth sense you've got there is still working. This computer does a lot of stuff and I have had a good portion of that set wrong, especially when I'm exploring new areas of the operating regime where I don't really know what the numbers should until I've run the engine there. Things are slowing down and getting more stable now, though. With longer runs and more power, I'll have to be more careful so I don't take the apex seal warper's job. BTW, is that a union gig? Is there at least a 50 pound CO2 fire extinguisher standing there with the pin out? Timing at 20 degrees BTDC is fine up to 9,000 RPM on low octane pump gas. Remember pump gas burns a bit faster than avgas. We are looking for best cylinder pressure at about 50 degrees after TDC not 18 degrees like a piston engine. Turbo engines at high boost can be at 10 degrees BTDC. Too much advance kills HP and adds heat. I think I should dedicate the next few runs to getting a better ignition table. I don't know if you've seen a MegaSquirt setup, or if other controllers are similar, Lynn, but the tuning process consists of modifying a grid of numbers with RPM and MAP values along the axis. There is a real-time ticker that shows where the controller is picking the current number out of the graph. With the arrow keys on the keyboard, you can move a separate ticker around and then use other keys to bump the grid values up and down. Up to this point, my tuning has consisted of letting the computer do it. Here is a good video of that process: http://www.youtube.com/watch?v=wLyk58f-u9I The manual tuning process, as I understand it, is to pick one of the tables. The ignition table in this case. Let the engine warm to operating temp, set the throttle and give it a few seconds to settle. Move to the grid cells surrounding the one where the real-time ticker is and move them up or down until the MAP is minimized. Move the throttle to a different position and repeat. An experienced ear could tell me immediately that I'm running to rich or lean or how the advance should change, but I'm still doing a lot of guessing with the "poke it and see what happens" technique. Do you have any tricks of what to look for when tuning the ignition advance? ------=_NextPart_000_0013_01CC3C88.579F0580 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Ernest,

=

 

Someone could correct me, but I = don’t think the EC-2 moves the ignition timing a whole lot.  Since you = are inventing this tuning for your system, why don’t you set your = timing at a constant spot, say 20 degrees like Lynn suggested, and then tune the fuel map.  After you get the fuel = pretty good, then you can go back and try and improve it with the = ignition.  Then do another pass with the fuel.  You should be there at that = point…well you can always hope!

 

You didn’t say anything about = the fire extinguisher….that could be more important than the = tuning!  If you think your wife was upset over the exhaust smell, wait till you = smoke damage her new wallpaper!  :>)

 

Bill B

 

From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ernest Christley
Sent: Thursday, July 07, = 2011 7:57 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = fuel flow

 

On 07/07/2011 06:51 AM, Lehanover@aol.com wrote: =

I suggest adding a bunch of = fuel first. Then lean back to take off power at about 50 to 100 degrees = rich of peak power/EGT, or under 1600 degrees. Or F/A in the 12s. We have people = in charge of warping apex seals. You do not need to cover that = again.

 

Roger that.  The issue is knowing what = number to put in to get bunch-o-fuel.  I thought my VE numbers set to over = 100 would be good.  The tuning software came back at me with suggestions of = 175 after the short power run.

I sense a lack of check = list. I detect more than one change at a time.

(a dyno room = violation)

That sixth sense you've got there is still working.  This computer does a lot of stuff and I have had a good = portion of that set wrong, especially when I'm exploring new areas of the = operating regime where I don't really know what the numbers should until I've run = the engine there.   Things are slowing down and getting more = stable now, though.  With longer runs and more power, I'll have to be more = careful so I don't take the apex seal warper's job.  BTW, is that a union = gig?

Is there at least a 50 = pound CO2 fire extinguisher standing there with the pin = out?

 

Timing at 20 degrees BTDC is fine up to 9,000 = RPM on low octane pump gas. Remember pump gas burns a bit faster than avgas. We = are looking for best cylinder pressure at about 50 degrees after TDC not 18 = degrees like a piston engine. Turbo engines at high boost can be at 10 degrees = BTDC. Too much advance kills HP and adds = heat.  

 


I think I should dedicate the next few runs to getting a better ignition table.  I don't know if you've seen a MegaSquirt setup, or if other controllers are similar, Lynn, but the tuning process consists of modifying a grid of numbers with RPM = and MAP values along the axis.  There is a real-time ticker that shows = where the controller is picking the current number out of the graph.  With = the arrow keys on the keyboard, you can move a separate ticker around and then use = other keys to bump the grid values up and down.

Up to this point, my tuning has consisted of letting the computer do = it.  Here is a good video of that process:
http://www.youtube.= com/watch?v=3DwLyk58f-u9I

The manual tuning process, as I understand it, is to pick one of the = tables. The ignition table in this case.  Let the engine warm to operating = temp, set the throttle and give it a few seconds to settle.  Move to the = grid cells surrounding the one where the real-time ticker is and move them up = or down until the MAP is minimized.  Move the throttle to a different position and repeat.  An experienced ear could tell me immediately = that I'm running to rich or lean or how the advance should change, but I'm = still doing a lot of guessing with the "poke it and see what = happens" technique.  Do you have any tricks of what to look for when tuning = the ignition advance?

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