X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3888706 for flyrotary@lancaironline.net; Fri, 16 Oct 2009 18:07:15 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (sv1-1.per.aanet.com.au [203.24.100.68]) by poplet2.per.eftel.com (Postfix) with ESMTP id 5EC87173938 for ; Sat, 17 Oct 2009 06:06:37 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id DB7F6BEC00F for ; Sat, 17 Oct 2009 06:06:35 +0800 (WST) Message-ID: <2157061E808C478DBCA0FF620E1A1AA6@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Stoich A/F Ratio?? : [FlyRotary] Re: where's the missing power? Date: Sat, 17 Oct 2009 08:06:37 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0026_01CA4F00.BFDE4650" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 091016-0, 10/16/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0026_01CA4F00.BFDE4650 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ed, Isn't the wide band sensor more prone to giving false readings ( = corruption) due to fouling. George ( down under) Hi Bill, =20 I could be wrong, but, I'm fairly certain that the position of the Ec2 = manual mixture control does not necessarily have any deterministic = relationship to air/fuel ratio of the EC2. The resulting air/fuel ratio = is a combination of (among other things) the MCT bin (pointed to by = manifold pressure) in which the engine is operating plus the effect of = the manual mixture control knob. =20 =20 The narrow band O2 sensor response curve is pretty crappy for any sort = of linear interpolation - but, most have a range of from a few 10 = millivolts to approx 1.1 volt. With the higher voltage 1.0 representing = higher air/fuel ratios - somewhere in the vicinity of 12 - 10 :1 = air/fuel ratio. Stioch (14.7:1) voltage is normally around 0.45 volts = (or 450 millvolts) and that is generally the only value that is really = rather accurate on a narrow band O2 sensor. =20 =20 So with my EFISM if the air/fuel ratio indictor is in the middle of = its range on the display, it should be yellow in color. I also have a = feature that when looking at the air/fuel indicator screen (the one with = fuel flow and fuel used values displayed), if you press button b3 and b4 = together you will get displayed in the air/fuel ratio window of the = actual voltage being read from the O2 sensor. So if the EFISM indicator = is yellow and in the middle the voltage should read somewhere close to = 450 mv. IF it is green and near the right hand limit the voltage will = probably be reading around 900 mv indicating an higher air/fuel ratio. = If red and to the left side then it will be reading less than 450 mv. =20 =20 However, remember that the curve for the narrow band O2 sensor is not = very suitable for interpolation. The wide band O2 sensor is much better = and therefore you can get more accurate indication of air/fuel ratio. =20 So almost all narrow band O2 air/fuel ratio indictors are only useful = in giving you a relative indication of leaner or richer. =20 In fact, I am considering a future modification/option/user selectable = Narrow band or wide band O2 sensor for the EFISM. Initially the wide = band O2 sensors were in the $250 -$300 range, but now have dropped down = to around $80 for the borsch model which makes them more cost feasible. =20 I probably did not answer your question, but that is as close as I = could come. =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Bill Bradburry Sent: Friday, October 16, 2009 8:57 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Stoich A/F Ratio?? : [FlyRotary] Re: where's = the missing power? =20 Good point, Ed. How much change does the mixture knob on the EC-2/3 allow? Say for = instance, if Mike was at 14.7 at full throttle with the mixture knob at = the center position, how far would he have to turn the knob to the right = to achieve 12.65 AFR? I ask this because the A/F gage will not read = that mixture. It will be topped out well before that mixture ratio = occurs. How do you determine best power mixture? Bill B =20 -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Ed Anderson Sent: Friday, October 16, 2009 8:35 AM To: Rotary motors in aircraft Subject: [FlyRotary] Stoich A/F Ratio?? : [FlyRotary] Re: where's the = missing power? Hi Mike, =20 I guess I'm missing something - If your mixture monitor shows stoich = at full throttle, then it's not solely an airflow problem - it appears = to me that it's the lack of sufficient fuel. IF you are at stoich 14.7:1 = A/F ratio then that means you have more oxygen available in your system = to support burning more fuel =3D more power. You should be able to = enrich the mixture particularly at full throttle (assuming you are = wanting full power at full throttle) to around 12.65:1 air/fuel ratio = for best power. I know you know all of this - that is why I am puzzled = by your statement that you feel it's an airflow problem when on the = surface with the Stoich ratio it would appear it's a lack of sufficient = fuel. =20 =20 =20 =20 Ed. =20 =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Mike Wills Sent: Thursday, October 15, 2009 11:22 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: where's the missing power? =20 Sorry for my absence on a topic I started. My nephew had a = skateboarding accident last weekend and is in the hospital in a = chemically induced coma until his brain swelling is under control. And I = thought car powered airplanes were dangerous. Stay away from = skateboards. =20 Tracy - My mixture monitor shows stoich at full throttle. I suspect an = airflow issue rather than fuel. =20 Al - my vacuum gauge is located in the plenum directly behind the = throttle plates. =20 Lynn - I agree that the TB inlet is horrible and needs a bell mouth. = The inlet is also pretty obstructed by the cowl which isnt visible in = the pics I sent. I think I'll make an attempt to clean this up some and = see if it gets me anywhere. If not I'll live with it for a while. =20 Kelly - always tough to determine if the problem is an engine issue or = if the load is simply too much for the engine to overcome. I'm going to = experiment with the shallow dive several have suggested and see what = happens. =20 Mike ----- Original Message -----=20 From: Bill Bradburry=20 To: Rotary motors in aircraft=20 Sent: Tuesday, October 13, 2009 4:21 PM Subject: [FlyRotary] Re: where's the missing power? =20 Since you have the vacuum gauge, this article will help you use it = for troubleshooting. =20 http://autospeed.com/cms/A_2393/article.html =20 Bill B =20 -------------------------------------------------------------------------= --- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Al Gietzen Sent: Tuesday, October 13, 2009 7:22 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: where's the missing power? I dont have a regular manifold pressure gauge, just an industrial = type vacuum gauge ( I really gotta get an MP gauge). Anyway, the vacuum = gauge was indicating 4" of vacuum. =20 Where are you measuring the 4" vacuum? If it is near the ports it = is no unusual; if it is out before the runners; something is wrong. =20 Al __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ------=_NextPart_000_0026_01CA4F00.BFDE4650 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ed,
Isn't the wide band sensor more prone = to giving=20 false readings ( corruption) due to fouling.
George ( down under)

Hi=20 Bill,

 

I could be = wrong,=20 but, I=92m fairly certain that the position of the Ec2  manual = mixture=20 control does not necessarily have any deterministic relationship to = air/fuel=20 ratio of the EC2. The resulting air/fuel ratio is a combination of = (among=20 other things) the MCT bin (pointed to by manifold pressure)  in = which the=20 engine is operating plus the effect of the manual mixture control = knob. =20

 

The narrow = band O2=20 sensor response curve is pretty crappy for any sort of linear = interpolation =96=20 but, most have a range of from a few 10 millivolts to approx 1.1 = volt. =20 With the higher voltage 1.0 representing higher air/fuel ratios =96 = somewhere in=20 the vicinity of 12 =96 10 :1 air/fuel ratio.  Stioch =  (14.7:1) voltage=20 is normally around 0.45 volts (or 450 millvolts) and that is generally = the=20 only value that is really rather accurate on a narrow band O2 = sensor. =20

 =20

So with my = EFISM if=20 the air/fuel ratio indictor is in the middle of its range on the = display, it=20 should be yellow in color.  I also have a feature that when = looking at=20 the air/fuel indicator screen (the one with fuel flow and fuel used = values=20 displayed), if you press button b3 and b4 together you will get = displayed in=20 the air/fuel ratio window of the actual voltage being read from the O2 = sensor.  So if the EFISM indicator is yellow and in the middle = the=20 voltage should read somewhere close to  450 mv.  IF it is = green and=20 near the right hand limit the voltage will probably be reading around = 900 mv=20 indicating an higher air/fuel ratio.  If red and to the left side = then it=20 will be reading less than 450 mv. 

 

However, = remember=20 that the curve for the narrow band O2 sensor is not very suitable for=20 interpolation.  The wide band O2 sensor is much better and = therefore you=20 can get more accurate indication of air/fuel=20 ratio.

 

So almost = all narrow=20 band O2 air/fuel ratio indictors are only useful in giving you a = relative=20 indication of leaner or richer.

 

In fact, I = am=20 considering a future modification/option/user selectable Narrow band = or wide=20 band O2 sensor for the EFISM.  Initially the wide band O2 sensors = were in=20 the $250 -$300 range, but now have dropped down to around $80 for the = borsch=20 model which makes them more cost = feasible.

 

I probably = did not=20 answer your question, but that is as close as I could=20 come.

 

Ed

 

Ed=20 Anderson

Rv-6A = N494BW Rotary=20 Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Bill Bradburry
Sent: Friday, October 16, 2009 = 8:57=20 AM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: Stoich = A/F=20 Ratio?? : [FlyRotary] Re: where's the missing=20 power?

 

Good point, Ed.

How much change does the mixture knob on the = EC-2/3=20 allow?  Say for instance, if Mike was at 14.7 at full throttle = with the=20 mixture knob at the center position, how far would he have to turn the = knob to=20 the right to achieve 12.65 AFR?  I ask this because the A/F gage = will not=20 read that mixture.  It will be topped out well before that = mixture ratio=20 occurs.  How do you determine best power=20 mixture?

Bill B

 

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Ed Anderson
Sent: Friday, October 16, 2009 = 8:35=20 AM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Stoich A/F = Ratio?? :=20 [FlyRotary] Re: where's the missing = power?

Hi=20 Mike,

 

I guess = I=92m missing=20 something - If your mixture monitor shows stoich at full throttle, = then it=92s=20 not solely an airflow problem =96 it appears to me that it=92s the = lack of=20 sufficient fuel. IF you are at stoich 14.7:1 A/F ratio then that means = you=20 have more oxygen available in your system to support burning more fuel = =3D more=20 power.   You should be able to enrich the mixture = particularly at=20 full throttle (assuming you are wanting full power at full throttle) = to around=20 12.65:1 air/fuel ratio for best power.  I know you know all of = this -=20 that is why I am puzzled by your statement that you feel it=92s an = airflow=20 problem when on the surface with the Stoich ratio it would appear = it=92s a lack=20 of sufficient fuel. 

 

 

 

Ed. =20

 

Ed=20 Anderson

Rv-6A = N494BW Rotary=20 Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.r= otaryaviation.com/Rotorhead%20Truth.htm

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Mike Wills
Sent: Thursday, October 15, = 2009 11:22=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: = where's the=20 missing power?

 

Sorry for my absence on = a=20 topic I started. My nephew had a skateboarding accident last = weekend and=20 is in the hospital in a chemically induced coma until his brain = swelling is=20 under control. And I thought car powered airplanes were dangerous. = Stay away=20 from skateboards.

 

Tracy - My=20 mixture monitor shows stoich at full throttle. I suspect an airflow = issue=20 rather than fuel.

 

Al - my vacuum gauge is = located in=20 the plenum directly behind the throttle=20 plates.

 

Lynn - I agree=20 that the TB inlet is horrible and needs a bell mouth. The inlet is = also pretty=20 obstructed by the cowl which isnt visible in the pics I sent. I think = I'll=20 make an attempt to clean this up some and see if it gets me anywhere. = If not=20 I'll live with it for a while.

 

Kelly - always tough to = determine=20 if the problem is an engine issue or if the load is simply too much = for the=20 engine to overcome. I'm going to experiment with the shallow dive = several have=20 suggested and see what happens.

 

Mike

----- Original Message = -----=20

From: Bill=20 Bradburry

To: Rotary motors in = aircraft=20

Sent:=20 Tuesday, October 13, 2009 4:21 PM

Subject:=20 [FlyRotary] Re: where's the missing=20 power?

 

Since you have the vacuum gauge, this = article will=20 help you use it for troubleshooting.

 

 http://autospeed.co= m/cms/A_2393/article.html

 

Bill B

 

From:=20 Rotary motors in = aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Al Gietzen
Sent: Tuesday, October 13, = 2009 7:22=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: = where's the=20 missing power?

I dont have a regular = manifold=20 pressure gauge, just an industrial type vacuum gauge ( I really = gotta get an=20 MP gauge). Anyway, the vacuum gauge was indicating 4" of=20 vacuum.

 

Where = are you=20 measuring the 4=94 vacuum?  If it is near the ports it is no = unusual; if=20 it is out before the runners; something is=20 wrong.

 

Al



__________ Information from ESET = NOD32=20 Antivirus, version of virus signature database 3267 (20080714)=20 __________

The message was checked by ESET NOD32 = Antivirus.

http://www.eset.com



__________ Information from ESET = NOD32=20 Antivirus, version of virus signature database 3267 (20080714)=20 __________

The message was checked by ESET NOD32 = Antivirus.

http://www.eset.com

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