X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 30 [X] Return-Path: Received: from fed1rmmtao06.cox.net ([68.230.241.33] verified) by logan.com (CommuniGate Pro SMTP 5.1.4) with ESMTP id 1759311 for flyrotary@lancaironline.net; Sun, 14 Jan 2007 21:38:35 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.33; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao06.cox.net (InterMail vM.6.01.06.03 201-2131-130-104-20060516) with ESMTP id <20070115023748.MTNG2628.fed1rmmtao06.cox.net@fed1rmimpo02.cox.net> for ; Sun, 14 Jan 2007 21:37:48 -0500 Received: from BigAl ([72.192.132.90]) by fed1rmimpo02.cox.net with bizsmtp id BEe51W00D1xAn3c0000000; Sun, 14 Jan 2007 21:38:05 -0500 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] engine surging at low manifold pressure Date: Sun, 14 Jan 2007 18:38:02 -0800 Message-ID: <000001c7384e$2de18f30$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C7380B.1FC0C030" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C7380B.1FC0C030 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 We have recently tuned the Ec2 on a 20B & although it has helped it run a little smoother we still get alot of roughness & surging at idle from 15 to 18 inches Mp& especially when pulling back power Has anyone experienced this problem? The plane has been run on the ground, however the problem was just as bad in air in a descent.=20 =20 Lou & Paul N ES 117ES =20 Lou; =20 You'll probably need to spend a fair amount of time tuning, with an O2 sensor readout. But my first question is about the MAP. MAP at idle = ought to be more in the 10 - 11" range. Second question is have adjusted the mixture knob when it is surging to see if it can be improved. Surging = is most likely with a too lean mixture. =20 The transistion from the 'low' to 'high' table at 3000 rpm on my 20B = occurs around 13.5 -14.5" (table entries 7-9). Tuning in the transition region needs to be good, or it will cause surging as it transitions back and = forth. Also; if the 3000 rpm transition gets close to the staging point, it can = get really messed up if the tuning on across the stage point is not well = set. I found that moving the stage point up to about 17" helps stay away from = that problem. =20 I found that I could not get smooth running below about 1500 - 1600 rpm = when running on the primary injectors (in the housings). It idled much = better down to about 1000 rpm running on the secondary injectors that are out = at the throttle body. In my case, that puts them about 8-9" out from the ports; so either the distance, or the MSD injectors, makes the = difference. =20 =20 If you find it runs better on the secondary only, there is a simple = change to make. In the 20B version of the EC2, with the external staging = relay, you can do what I did and put the stage relay in the primary power = circuit so it runs on secondary only at low MAP; and the primary kick in above = the stage point. =20 Hope this helps. Best of luck. =20 Al G =20 =20 =20 =20 =20 =20 _________________________________________________________________________= ___ ________ Need Mail bonding? Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users. http://answers.yahoo.com/dir/?link=3Dlist&sid=3D396546091 =20 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ ------=_NextPart_000_0001_01C7380B.1FC0C030 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

We have recently tuned the Ec2 on a 20B & although it

has helped it run a little smoother we still get alot

of roughness & surging at idle from 15 to 18 inches

Mp& especially when pulling back power Has anyone

experienced this problem? The plane has been run on

the ground, however the problem was just as bad in air

in a descent.

 

Lou & Paul  N ES 117ES

 <= /font>

Lou;

 <= /font>

You’ll = probably need to spend a fair amount of time tuning, with an O2 sensor readout.  = But my first question is about the MAP.  MAP at idle ought to be more in = the 10 – 11” range.  Second question is have adjusted the mixture knob = when it is surging to see if it can be improved.  Surging is most likely = with a too lean mixture.

 <= /font>

The = transistion from the ‘low’ to ‘high’ table at 3000 rpm on my 20B = occurs around 13.5 -14.5” (table entries 7-9).  Tuning in the = transition region needs to be good, or it will cause surging as it transitions back = and forth.  Also; if the 3000 rpm transition gets close to the staging = point, it can get really messed up if the tuning on across the stage point is = not well set.  I found that moving the stage point up to about 17” = helps stay away from that problem.

 <= /font>

I found that = I could not get smooth running below about 1500 – 1600 rpm when running on = the primary injectors (in the housings).  It idled much better down to = about 1000 rpm running on the secondary injectors that are out at the throttle = body.  In my case, that puts them about 8-9” out from the ports; so = either the distance, or the MSD injectors, makes the difference. =  

 <= /font>

If you find = it runs better on the secondary only, there is a simple change to make.  In the = 20B version of the EC2, with the external staging relay, you can do what I = did and put the stage relay in the primary power circuit so it runs on secondary = only at low MAP; and the primary kick in above the stage = point.

 <= /font>

Hope this = helps.  Best of luck.

 <= /font>

Al = G

 <= /font>

 <= /font>

 

 

 

 

______________________________________________= ______________________________________

Need Mail bonding?

Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers = users.

http://answers.yahoo.com/dir/?link=3Dlist&= sid=3D396546091

 

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Homepage:  http://www.flyrotary.com/

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