X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db02.mx.aol.com ([205.188.91.96] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTP id 5384775 for flyrotary@lancaironline.net; Mon, 06 Feb 2012 11:16:04 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.96; envelope-from=bktrub@aol.com Received: from mtaomg-ma01.r1000.mx.aol.com (mtaomg-ma01.r1000.mx.aol.com [172.29.41.8]) by imr-db02.mx.aol.com (8.14.1/8.14.1) with ESMTP id q16GFNLU003057 for ; Mon, 6 Feb 2012 11:15:23 -0500 Received: from core-duc003b.r1000.mail.aol.com (core-duc003.r1000.mail.aol.com [172.29.164.137]) by mtaomg-ma01.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 57F43E000092 for ; Mon, 6 Feb 2012 11:15:23 -0500 (EST) References: To: flyrotary@lancaironline.net Subject: Re: [FlyRotary] Re: Upper end tuning In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: bktrub@aol.com X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8CEB301A9AFE82F_1F0C_77E38_webmail-m021.sysops.aol.com" X-Mailer: AOL Webmail 35412-STANDARD Received: from 50.46.146.205 by webmail-m021.sysops.aol.com (64.12.183.102) with HTTP (WebMailUI); Mon, 06 Feb 2012 11:15:22 -0500 Message-Id: <8CEB301A99F3E65-1F0C-1EA14@webmail-m021.sysops.aol.com> X-Originating-IP: [50.46.146.205] Date: Mon, 6 Feb 2012 11:15:22 -0500 (EST) x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1328544923; bh=+iUcaqGfTLeWquUUr9YLKqquYGgMDEzPSPlBheJrxfQ=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=VoqI1bESph7hkomIHJ4gvOwC3owpkfPodVOAEpSX9VW7We+9MgPvDodVKUaUMaUcU AKj8Ca/KB3Uhxc8liFQ3sAgIdofwNZiXnr8DRh1a2gZdZSe6YOjWMfH6ep7myk9T40 hlW7aENZKsoC8ZXZnpmPHS0mWQVMcPlZNCGob/rU= X-AOL-SCOLL-SCORE: 0:2:469203072:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d29084f2ffc9b573e This is a multi-part message in MIME format. ----------MB_8CEB301A9AFE82F_1F0C_77E38_webmail-m021.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" This was at any altitude- I'll take off at sea level and on climb out if t= he rpms get to 6100, the engine stumbles as if it were suddenly way too lea= n. So, what I'm saying is that this can happen at any altitude. It seems to= be more of a RPM issue than of manifold pressure. As far as the EGT goes, it may be an instrumentation error.=20 I've tried to richen up the mixture and then go up past 6100 rpm, but I sti= ll get the power drop. And yes, I have the EM2 set at the factory setting for engine max power, so= all I'm seeing is just an arbitrary number.=20 So, I'm going to change spark plugs and do some more flying. The weather is= nice out here for the next few days so I have some opportunity to fully ex= plore what's going on.=20 Brian Trubee -----Original Message----- From: Tracy To: Rotary motors in aircraft Sent: Mon, Feb 6, 2012 6:00 am Subject: [FlyRotary] Re: Upper end tuning Can't make an educated guess from the data given but here's a few questions= & comments. Can you clarify what you mean by "precipitous power drop"? Does the power = go down at higher MP? (6100 at 22.6" aint bad on a FP prop. What was the = airspeed & altitude? EVERYTHING MATTERS!) Is the EGT imbalance only at high power? Are you sure it's not instrumenta= tion error? As Ed asked, what was the result of varying the mixture control at high pow= er? =20 You say that engine is silky smooth below 6100. Does that imply it is roug= h above 6100? The % power readout of the EM2 is meaningless if the fuel flow function isn= 't calibrated and you haven't plugged in a realistic value for your engine'= s max power. Tracy On Sun, Feb 5, 2012 at 10:01 PM, wrote: I've got just over 20 hours on my plane today, all of the lower- end bugs h= ave been worked out. Right now I'm having power drop off precipitously righ= t at 6100 rpm- 22.6 inches of MP and around 70% power according to the EM2.= This is around 130-140 mph IAS. The fuel injection Map shows a smooth grap= h at that point. I thought that there might be a timing issue so I tried ad= vancing the timing about 2 degrees but that did not change a thing so I set= the timing back where it was previously. I am seeing about a 180 f differe= nce on the two rotors- I went to mode four to try to balance out the egts, = but I could only effect about a 20 degree change. Rotor 2 consistently show= s somewhere above 1800 F, which I tend to question. I'll re-check my calibr= ation. I have had the injectors cleaned and tested so unless one of them = got clogged, that should not be an issue. Still, I should pull them and hav= e them re-checked. I may have an issue with the EGT probes themselves.=20 =20 Down below 6100 rpm the engine is smooth as silk, but obviously there is a= n issue above that .=20 =20 =20 Brian Trubee RV-4 13 BREW =20 ----------MB_8CEB301A9AFE82F_1F0C_77E38_webmail-m021.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii"
This was at any altitude- I'll take off at sea level  and on clim= b out if the rpms get to 6100, the engine stumbles as if it were suddenly w= ay too lean. So, what I'm saying is that this can happen at any altitude. I= t seems to be more of a RPM issue than of manifold pressure.
 
As far as the EGT goes, it may be an instrumentation error.
 
I've tried to richen up the mixture and then go up past 6100 rpm, but = I still get the power drop.
 
And yes, I have the EM2 set at the factory setting for engine max powe= r, so all I'm seeing is just an arbitrary number.
 
So, I'm going to change spark plugs and do some more flying. The weath= er is nice out here for the next few days so I have some opportunity to ful= ly explore what's going on.
 
Brian Trubee


= -----Original Message-----
From: Tracy <rwstracy@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, Feb 6, 2012 6:00 am
Subject: [FlyRotary] Re: Upper end tuning

Can't make an e= ducated guess from the data given but here's a few questions & comments= .

Can you clarify what you mean by "precipitous power drop"?  Does the p= ower go down at higher MP?  (6100 at 22.6" aint bad on a FP prop. = ; What was the airspeed & altitude?  EVERYTHING MATTERS!)

Is the EGT imbalance only at high power?  Are you sure it's not instru= mentation error?

As Ed asked, what was the result of varying the mixture control at high pow= er? 

You say that engine is silky smooth below 6100.  Does that imply it is= rough above 6100?

The % power readout of the EM2 is meaningless if the fuel flow function isn= 't calibrated and you haven't plugged in a realistic value for your engine'= s max power.

Tracy


On Sun, Feb 5, 2012 at 10:01 PM, &= lt;bktrub@aol.com> wrote:
I've got just over 20 hours on my plane today, all of the lower- end b= ugs have been worked out. Right now I'm having power drop off precipitously= right at 6100 rpm- 22.6 inches of MP and around 70% power according to the= EM2. This is around 130-140 mph IAS. The fuel injection Map shows a smooth= graph at that point. I thought that there might be a timing issue so I tri= ed advancing the timing about 2 degrees but that did not change a thing so = I set the timing back where it was previously. I am seeing about a 180 f di= fference on the two rotors- I went to mode four to try to balance out the e= gts, but I could only effect about a 20 degree change. Rotor 2 consistently= shows somewhere above 1800 F, which I tend to question. I'll re-check my c= alibration.   I have had the injectors cleaned and tested so unle= ss one of them got clogged, that should not be an issue. Still, I should pu= ll them and have them re-checked. I may have an issue with the EGT probes t= hemselves.
 
 Down below 6100 rpm the engine is smooth as silk, but obviously = there is an issue above that .
 
 
Brian Trubee
RV-4  13 BREW
 

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