X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao105.cox.net ([68.230.241.41] verified) by logan.com (CommuniGate Pro SMTP 5.3.0) with ESMTP id 4068794 for flyrotary@lancaironline.net; Thu, 07 Jan 2010 22:47:40 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.41; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao105.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100108034705.CXML12229.fed1rmmtao105.cox.net@fed1rmimpo01.cox.net> for ; Thu, 7 Jan 2010 22:47:05 -0500 Received: from willsPC ([68.105.91.112]) by fed1rmimpo01.cox.net with bizsmtp id Srn41d00A2RT1vG03rn5B3; Thu, 07 Jan 2010 22:47:05 -0500 X-VR-Score: -160.00 X-Authority-Analysis: v=1.1 cv=4cmh2gL1a6RJOvq2diO5/mV5P7W7DelkioqUudxRLMU= c=1 sm=1 a=Fd91bCVGJ9sA:10 a=lTdc4wscJffengO6xjBlCw==:17 a=N8B9JuSIAAAA:8 a=kviXuzpPAAAA:8 a=c2J9_UBuMQ9AUelZnsAA:9 a=v-YDHMkG5NoRlTVyfblEni3B4sMA:4 a=4vB-4DCPJfMA:10 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=GI45IrtxVHm12ZCPx3YA:9 a=1KSV4FyKycjgxBErBh8A:7 a=gVUJIJiN2MoTgnsUXv_m3Vr07q0A:4 a=MSl-tDqOz04A:10 a=EzXvWhQp4_cA:10 a=lTdc4wscJffengO6xjBlCw==:117 X-CM-Score: 0.00 Message-ID: <37D4B29A7B134DEB86F50684F857DAD5@willsPC> From: "Mike Wills" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: first flight of the new year Date: Thu, 7 Jan 2010 19:47:05 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0076_01CA8FD2.309E1110" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_0076_01CA8FD2.309E1110 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Dave (and Al), Thanks for the data points. I havent done any experimenting yet with = lean of peak ops. My EGTs seem to be pretty well balanced with only a 10 = - 20 degree spread max at cruise settings. So I should be pretty well = set for LOP, just havent messed with it yet. French Valley is outside my test area. So far I havent really flown = anywhere but Borrego and back, but I'm going to start expanding that a = little. The trip to Borrego is getting boring. Mike=20 From: David Leonard=20 Sent: Thursday, January 07, 2010 9:07 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: first flight of the new year Again, my experience is very similar to Al's. I cruse between 6k' and = 17k' depending on the winds. That gives quite a range of variables. = Interestingly though, regardless of altitude and RPM etc, about 8 gph = seems to hit the narrow sweet spot with my EGT's (actually TOT) below = 900C (about 1600F) and yet the engine not running too rough (giving me = about 155KTAS). Yes, the RPM decreases quite noticeably when going to = the lean side of peak and the engine is not as smooth (I have grown used = to it, but I think Al really notices when he flies in my plane). In = order to help my turbo last longer, I avoid peak EGT pretty religiously = (that seems to be working so far, over 200 hrs on current turbo). At = the lean setting, the O2 sensor off the lean end of the scale. Because of my turbo Manifold, I am unable to install individual EGT = sensors for each rotor, so my rotors are still slightly unbalanced = (probably most of the problem with roughness). Besides, even if you = were able to get them perfectly balanced at one RPM, it would change = slightly at a different RPM/power setting. =20 Without the turbo, you should be able to safely run closer to peak EGT = or best power without risk of damaging anything. --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Wed, Jan 6, 2010 at 10:19 PM, Al Gietzen wrote: For cruise do you lean enough that you notice any reduction in engine = RPM? What sort of fuel flows, manifold pressure, and cruise speeds are = you getting and at what altitude? For it to run well very lean the mixtures to the rotors need to be = balanced =96 similar EGTs; so you may want to do whatever mode that is. = You can get a handle on good lean cruise and max power by watching the = EGT. I tend to run about 100 lean of peak for cruise. Although it will = do fine leaner, it doesn=92t fell quite as smooth. You=92ll have to add = some throttle to maintain rpm. Max power is somewhere about 150+ rich of = peak IIRC from the dyno runs. I typically cruise 5400-5500 rpm, 9.5 =96 10.5 Kft, maybe 9.7 gph on = my 3-rotor; so you should get the 2-rotor in the area of 6.5. That gives = me 165+ KTAS in my 4-place Velocity =96 not bad. Could get better = economy going slower, but unless I=92m just sight-seeing, I wanna get = there. Does your test area extend to French Valley? Al ------=_NextPart_000_0076_01CA8FD2.309E1110 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Dave (and Al),
 
 Thanks for the data points. I havent = done any=20 experimenting yet with lean of peak ops. My EGTs seem to be pretty well = balanced=20 with only a 10 - 20 degree spread max at cruise settings. So I should be = pretty=20 well set for LOP, just havent messed with it yet.
 
French Valley is outside my test area. So far = I havent=20 really flown anywhere but Borrego and back, but I'm going to start=20 expanding that a little. The trip to Borrego is getting = boring.
 
Mike 

Sent: Thursday, January 07, 2010 9:07 AM
Subject: [FlyRotary] Re: first flight of the new=20 year

Again, my experience is very similar to Al's.  I cruse between = 6k' and=20 17k' depending on the winds.  That gives quite a range of = variables. =20 Interestingly though, regardless of altitude and RPM etc, about 8 = gph seems=20 to hit the narrow sweet spot with my EGT's (actually = TOT) below=20 900C (about 1600F) and yet the engine not running too rough (giving = me=20 about 155KTAS).  Yes, the RPM decreases quite noticeably when going = to the=20 lean side of peak and the engine is not as smooth (I have grown used to = it, but=20 I think Al really notices when he flies in my plane).  In = order to=20 help my turbo last longer, I avoid peak EGT pretty religiously (that = seems to be=20 working so far, over 200 hrs on current turbo).  At the lean = setting, the=20 O2 sensor off the lean end of the scale.
 
Because of my turbo Manifold, I am unable to install individual EGT = sensors=20 for each rotor, so my rotors are still slightly unbalanced (probably = most of the=20 problem with roughness).  Besides, even if you were able to get = them=20 perfectly balanced at one RPM, it would change slightly at a different = RPM/power=20 setting. 
 
Without the turbo, you should be able to safely run closer to peak = EGT or=20 best power without risk of damaging anything.
 
--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.nethttp://RotaryRoster.net


<= /DIV>
On Wed, Jan 6, 2010 at 10:19 PM, Al Gietzen = <ALVentures@cox.net> = wrote:

 

For cruise do you lean = enough=20 that you notice any reduction in engine RPM? What sort of fuel flows, = manifold=20 pressure, and cruise speeds are you getting and at what=20 altitude?

 

For it to = run well=20 very lean the mixtures to the rotors need to be balanced =96 similar = EGTs; so=20 you may want to do whatever mode that is.  You can get a handle = on good=20 lean cruise and max power by watching the EGT.  I tend to run = about 100=20 lean of peak for cruise.  Although it will do fine leaner, it = doesn=92t=20 fell quite as smooth. You=92ll have to add some throttle to maintain = rpm. Max=20 power is somewhere about 150+ rich of peak IIRC from the dyno=20 runs.

 

I = typically cruise=20 5400-5500 rpm, 9.5 =96 10.5 Kft, maybe 9.7 gph on my 3-rotor; so you = should get=20 the 2-rotor in the area of 6.5. That gives me 165+ KTAS in my 4-place=20 Velocity =96 not=20 bad.  Could get better economy going slower, but unless I=92m = just=20 sight-seeing, I wanna get there.

 

Does your = test area=20 extend to French=20 Valley?

Al

 



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