X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from wx-out-0506.google.com ([66.249.82.234] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2331824 for flyrotary@lancaironline.net; Fri, 14 Sep 2007 22:34:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=66.249.82.234; envelope-from=msteitle@gmail.com Received: by wx-out-0506.google.com with SMTP id i27so889079wxd for ; Fri, 14 Sep 2007 19:34:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; bh=pL3vsof99SuKg0IhZlpDj+otZJlAvmq2EDDoQv2lb/k=; b=n5A3W7sgvrCsZNQJ/8TsWdPbE9r3DHwtsziyxwzTiQTuVMssUdchMMR/opZp2BRh02XRT7iYZJpVU2UDDDm1E45lVIsZYYPmpUtV/h6hOlmqU8zqjNqD3YPdZ7/IDQRNUpsP2bf0scqx0Et8mvZCgRUwrecs/WdcYVhcZ7H8Glg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=O5P6nKFdaXc2SgaUe/PxNNwQpPVS6xtq3JLjiVdv4dMQTxxQWQuSz6XvwZXqwmLBtF2fLbhNhC4x95TFvA0QuQtLYBGTebHDEpt2sZpqnSCOfRzlDE2GtEwUAYWROiOdkWzqHX3N+hKxp5xP26v7u8SnKpk9L+uwI/qkfne/byo= Received: by 10.90.102.20 with SMTP id z20mr665642agb.1189823658150; Fri, 14 Sep 2007 19:34:18 -0700 (PDT) Received: by 10.90.35.16 with HTTP; Fri, 14 Sep 2007 19:34:18 -0700 (PDT) Message-ID: <5cf132c0709141934g40ceaf0g86a9d3b7cc4831b8@mail.gmail.com> Date: Fri, 14 Sep 2007 21:34:18 -0500 From: "Mark Steitle" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: One for the smart guys In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_3205_1038394.1189823658140" References: ------=_Part_3205_1038394.1189823658140 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Ed, You're correct on the first assumption (problem was not related to pumps, filters, or fuel plumbing). I didn't mention it, but I had tried to adjust mixture during the mis-firing, but changing the mixture did not make any improvemnt. This was not an easy task to do while accelerating down the runway in a 300hp airplane that you've never flown before, all the while trying to keep it from becoming airborn. Most of the spark plug changing was due to gas fouling. The snubber upgrade fixed that problem. As for the injectors, they are not the problem (trust me on this one, ED). Although before the snubber fix came along I removed all six injectors and had them cleaned and flow checked. That little effort made no difference. (Kiss that $200 bucks good-bye.) Are you guys beginning to get the sense of how frustrated I had gotten. I was even considering switching to a carburetor (gag). I can sure understand Buly's frustration. OK, I'll give you a hint... it was related to my decision to change over from the original CAS to the Renesis CAS. I got that bright idea from last year's rotary get together at Tracy's. Mark S. On 9/14/07, Ed Anderson wrote: > Ok since it ran well in those rpm ranges before, we can assume its not > related to your pumps, filters or fuel plumbing since the EC2 does not > control those. > > If you had the auto tune feature and are using a narrow band O2 sensor, it > could be leaning out at the higher rpm due to the Z shape of the voltage > curve. But, I think that would be too subtle. > > If missing at higher rpm then its either fuel or spark. The higher rpm > mean higher manifold pressure and SAG is worst at high manifold pressure - > so if you changed your spark plugs and it got better, I would bet on the > SAG. > > I guess another possibility (just guessing) is that your third pair of > injectors were not firing at higher rpm. Another guess, is you never got > around to retuning your fuel map at the higher rpm after the snubber fix. > > OK, I give up > > Ed > > ----- Original Message ----- > *From:* Mark Steitle > *To:* Rotary motors in aircraft > *Sent:* Friday, September 14, 2007 7:54 PM > *Subject:* [FlyRotary] One for the smart guys > > > OK guys, here's one to think about. > > Problem: Major mis-fire at 6600 - 7000 rpm. Engine runs great up until > it begins mis-firing. This is a 20B running an EC-2 that's been updated > with the latest s/w (as of 9/1/07). This includes the snubber fix and a > modification for the Renesis CAS. Before the snubber upgrade, the engine > ran good in the upper rpm range, but not in the lower rpm range. After the > snubber upgrade & Renesis CAS modification, it ran great in the lower rpm > range, but had a serious mis-fire beginning around 3800 rpm. An attempt was > made to correct the mis-firing problem by installing a resistor/zener diode > circuit in the CAS lead (this strategy worked for another Renesis flyer). > This approach was partially successful, but only up to the mid 6K range. > > Multiple phone calls to Tracy resulted in no fix. I think he's hiding in > Colorado so he won't have to take my calls. (I'm kidding, of course.) > > Finally, today (after months of struggling) I discovered what was causing > the problem. It now runs great up to 7300 rpm, verified by a full-power run > down the runway. Anyone want to guess as to what the problem turned out to > be? > > Mark S. > > > > > ------=_Part_3205_1038394.1189823658140 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline
Ed,
 
You're correct on the first assumption (problem was not related to pumps, filters, or fuel plumbing).
 
I didn't mention it, but I had tried to adjust mixture during the mis-firing, but changing the mixture did not make any improvemnt.  This was not an easy task to do while accelerating down the runway in a 300hp airplane that you've never flown before, all the while trying to keep it from becoming airborn.
 
Most of the spark plug changing was due to gas fouling.  The snubber upgrade fixed that problem. 
 
As for the injectors, they are not the problem (trust me on this one, ED).  Although before the snubber fix came along I removed all six injectors and had them cleaned and flow checked.  That little effort made no difference.  (Kiss that $200 bucks good-bye.) 
 
Are you guys beginning to get the sense of how frustrated I had gotten.  I was even considering switching to a carburetor (gag).  I can sure understand Buly's frustration.
 
OK, I'll give you a hint... it was related to my decision to change over from the original CAS to the Renesis CAS.  I got that bright idea from last year's rotary get together at Tracy's. 
 
Mark S.
 
On 9/14/07, Ed Anderson <eanderson@carolina.rr.com> wrote:
Ok since it ran well in those rpm ranges before, we can assume its not related to your pumps, filters or fuel plumbing since the EC2 does not control those.
 
If you had the auto tune feature and are using a narrow band O2 sensor, it could be leaning out at the higher rpm due to the Z shape of the voltage curve.  But, I think that would be too subtle.
 
If missing at higher rpm then its either fuel or spark.  The higher rpm mean higher manifold pressure and SAG is worst at high manifold pressure - so if you changed your spark plugs and it got better, I would bet on the SAG.
 
I guess another possibility (just guessing) is that your third pair of injectors were not firing at higher rpm.  Another guess, is you never got around to retuning your fuel map at the higher rpm after the snubber fix.
 
OK, I give up
 
Ed
----- Original Message -----
Sent: Friday, September 14, 2007 7:54 PM
Subject: [FlyRotary] One for the smart guys

 
OK guys, here's one to think about. 
 
Problem:  Major mis-fire at 6600 - 7000 rpm.  Engine runs great up until it begins mis-firing.  This is a 20B running an EC-2 that's been updated with the latest s/w (as of 9/1/07).  This includes the snubber fix and a modification for the Renesis CAS.  Before the snubber upgrade, the engine ran good in the upper rpm range, but not in the lower rpm range.  After the snubber upgrade & Renesis CAS modification, it ran great in the lower rpm range, but had a serious mis-fire beginning around 3800 rpm.  An attempt was made to correct the mis-firing problem by installing a resistor/zener diode circuit in the CAS lead (this strategy worked for another Renesis flyer).  This approach was partially successful, but only up to the mid 6K range. 
 
Multiple phone calls to Tracy resulted in no fix.  I think he's hiding in Colorado so he won't have to take my calls. (I'm kidding, of course.) 
 
Finally, today (after months of struggling) I discovered what was causing the problem.  It now runs great up to 7300 rpm, verified by a full-power run down the runway.  Anyone want to guess as to what the problem turned out to be? 
 
Mark S.
 
 
 

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