Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2946114 for flyrotary@lancaironline.net; Fri, 23 Jan 2004 18:10:41 -0500 Received: from edward (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i0NNAYTf007258 for ; Fri, 23 Jan 2004 18:10:35 -0500 (EST) Message-ID: <003901c3e206$1c260240$2402a8c0@edward> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Air cleaner Date: Fri, 23 Jan 2004 18:10:36 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0036_01C3E1DC.33190BC0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0036_01C3E1DC.33190BC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message ----- Original Message -----=20 From: TWJames=20 To: Rotary motors in aircraft=20 Sent: Friday, January 23, 2004 2:02 PM Subject: [FlyRotary] Re: Air cleaner Hi All, I am so glad to read Rusty's honest appraisal of how it really works = in this experimental stuff. I'm thinking of naming my plane "Do & = Re-do". =20 Ten days ago in Pensacola, duh?, I set about to re-evaluate my mixture = map. (hint to Perry)(Thanks to Ed). I found that the average setting, = from 13" to 30" was 5-6 bars/10 on the meter. I reset in Mode 1 to 7-8 = bars. Went flying and power was good. However, takeoff roll rpm was = still low at 4500. As we accelerated to 5400 in level flight, the = mixture meter showed only 4-5 bars. I adjusted to 7 and kept the = mixture there for local flights at from 3-5000 with nothing but = smoothness. Questions: =20 1.Why would the WOT mixture decline in flight vs. static WOT? =20 2. Should I go for more TO power with slightly less pitch until it = will generate 6000 +- with WOT in level flight? Regards, Tommy the lurker ps WOT Temps never got above 197* with OAT at 60-65*, even at 80kt = climb Hi Tommy, I'll try to answer your questions. First if your take off is 4500 = rpm (which is low) and your can accelerate to 5400 rpm (which is not = high) and your bars are in the 5-6 range then you are basically still = below the air fuel mixture for best power. I suspect that you may be = encountering some airflow challenges with your intake as I would expect = like to see you closer to 5000 rpm for take off and 5900-6000 rpm for = the upper end. OR you simple have more prop pitch than optimum for take = off. =20 Here is what I would suggest. I would set the prop so you can get = 5000 rpm static (you might want to work up to that in several stages and = noting how it effects your top end in flight). AT 5000 rpm static = (ready for take off roll), I would crank the manual mixture control up = until I see around 8-9 on the LED. Asssuming that max LED number 10 can = be make to light up. The reason I state that is the LEDs are measuring = the O2 sensor voltage from approx 0 - 1 volt. Depending on the O2 = sensor (or the calibration of the LED indicator), its possible for the = number 10 LED to be lit and yet you only have an air/fuel ratio of say = 13 instead of the optimum for best power which is around 12.6:1. =20 Air/fuel ratio =3D POWER. So you generally want the maximum - = particularly for take off which generally means around 9-10 on the LED = scale. Also note your EGT, as long as it tends to increase that means = the fuel is being used to produce power, if you advance the mixture too = rich you will note that the EGT starts to drop off. Now if you lean it = too much the EGT will also drop off, but with the LED indicator its = generally easy to tell which one is happening. If you are at 10 LED and = the EGT is dropping then you probably have it too rich. IF you are 5 or = below and the EGT is dropping then you are getting lean. Its not unusually to have to manually adjust the mixture control to = keep it where you want it for your particular regime of flight. Many = factors seems to affect its operating position. When I lean out for = economy cruise the LED are not lit - too lean to show on the scale and = my fuel flow is around 6.7-7 gph.=20 By the way, once we get the fuel flow indicator working for you, you = will find that with the LED and Fuel Flow indicator, you really get a = much better picture of what you are doing with the engine. Hope this helps. Once you get the aircraft to NC , let me know and we = can do some more "experimenting" Ed Anderson =20 ------=_NextPart_000_0036_01C3E1DC.33190BC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
 
 ----- Original Message -----
From:=20 TWJames
Sent: Friday, January 23, 2004 = 2:02=20 PM
Subject: [FlyRotary] Re: Air=20 cleaner

Hi=20 All,
I am=20 so glad to read Rusty's honest appraisal of how it really works in = this=20 experimental stuff.  I'm thinking of naming my plane "Do &=20 Re-do". 
 
Ten=20 days ago in Pensacola, duh?, I set about to re-evaluate my mixture = map. =20 (hint to Perry)(Thanks to Ed).  I found that the average setting, = from=20 13" to 30" was 5-6 bars/10 on the meter.  I reset in Mode 1 to = 7-8=20 bars.  Went flying and power was good. However, takeoff = roll rpm was=20 still low at 4500.  As we accelerated to 5400 in level flight, = the=20 mixture meter showed only 4-5 bars.  I adjusted to 7 and kept the = mixture=20 there for local flights at from 3-5000 with nothing but=20 smoothness.
Questions: 
1.Why would the WOT mixture decline in flight vs. static = WOT? =20
2. Should I go for more TO power with slightly less = pitch=20 until it will generate 6000 +- with WOT in level = flight?
 
Regards,
Tommy the lurker
ps=20 WOT Temps never got above 197* with OAT at 60-65*, even at 80kt=20 climb
 
Hi=20 Tommy,
 
   =20 I'll try to answer your questions.  First if your take off is = 4500 rpm=20 (which is low) and your can accelerate to 5400 rpm (which is not high) = and=20 your bars are in the 5-6 range then you are basically still below the = air fuel=20 mixture for best power.    I suspect that you may be=20 encountering some airflow challenges with your intake as I would = expect like=20 to see you closer to 5000 rpm for take off and 5900-6000 rpm for the = upper=20 end.  OR you simple have more prop pitch than optimum for take = off. =20
 
   Here=20 is what I would suggest.  I would set the prop so you = can get=20 5000 rpm static (you might want to work up to that in several stages = and=20 noting how it effects your top end in flight).  AT 5000 rpm = static (ready=20 for take off roll), I would crank the manual mixture control up until = I see=20 around 8-9 on the LED.  Asssuming that max LED number 10 can be = make to=20 light up.  The reason I state that is the LEDs are measuring the = O2=20 sensor voltage from approx 0 - 1 volt.  Depending on the O2 = sensor (or=20 the calibration of the LED indicator), its possible for the number 10 = LED to=20 be lit and yet you only have an air/fuel ratio of say 13 instead of = the=20 optimum for best power which is around 12.6:1.  =
 
   =20 Air/fuel ratio =3D POWER.  So you generally want the maximum - = particularly=20 for take off which generally means around 9-10 on the LED scale.  = Also=20 note your EGT, as long as it tends to increase that means the fuel is = being=20 used to produce power, if you advance the mixture too rich you will = note that=20 the EGT starts to drop off.  Now if you lean it too much the EGT = will=20 also drop off, but with the LED indicator its generally easy to tell = which one=20 is happening.  If you are at 10 LED and the EGT is dropping then = you=20 probably have it too rich.  IF you are 5 or below and the EGT is = dropping=20 then you are getting lean.
 
Its = not unusually=20 to have to manually adjust the mixture control to keep it where you = want it=20 for your particular regime of flight.  Many factors seems to = affect its=20 operating position.  When I lean out for economy cruise the LED = are not=20 lit - too lean to show on the scale and my fuel flow is around 6.7-7 = gph.=20
 
By = the way, once=20 we get the fuel flow indicator working for you, you will find that = with the=20 LED and Fuel Flow indicator, you really get a much better picture of = what you=20 are doing with the engine.
 
Hope = this=20 helps.  Once you get the aircraft to NC , let me know and we can = do some=20 more "experimenting"
 
Ed=20 Anderson
 
  =20
 
   =20
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