X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.123] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3888935 for flyrotary@lancaironline.net; Fri, 16 Oct 2009 22:33:29 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.123; envelope-from=eanderson@carolina.rr.com Received: from computername ([75.191.186.236]) by cdptpa-omta02.mail.rr.com with ESMTP id <20091017023254194.BIRK16243@cdptpa-omta02.mail.rr.com> for ; Sat, 17 Oct 2009 02:32:54 +0000 From: "Ed Anderson" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Stoich A/F Ratio?? : [FlyRotary] Re: where's the missing power? Date: Fri, 16 Oct 2009 22:32:57 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000C_01CA4EB0.9C6CB120" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 In-Reply-To: Thread-Index: AcpOyphbhJ/ktrIZRzir/VpZ/JaZfQABlWGw X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Message-Id: <20091017023254194.BIRK16243@cdptpa-omta02.mail.rr.com> This is a multi-part message in MIME format. ------=_NextPart_000_000C_01CA4EB0.9C6CB120 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Well, George, my take is the wide band sensor would probably do fine = just providing a voltage output which is all we use for an air/fuel ratio indication. However, in a automobile application they are using it to control the CPU and therefore the engine injectors to keep the engine operating at the ratio of 14.7:1. As I understand it they basically use = a saw tooth wave form that=92s centered around the 14.7:1 voltage point = and compare it to the output of the O2 sensor. The difference is used to provide a indication to the CPU as to whether to enrich or lean the = mixture. =20 The lead in the gasoline apparently does not affect the voltage = output, but does affect the response time of the sensor to this varying voltage = wave form =96 it slows it down to the point it becomes unable to adequately = control the CPU to maintain 14.7:1. =20 So my take is the lead does not apparently affect the voltage output of = the sensor just slows it down too much to be useful in its intended = application. But, I could be incorrect in my understanding and about the effects of = lead. =20 However, IF Bosch claims it takes 200 hours of leaded fuel before the = wide band is degraded to the point of not being useful in its intended = automobile application, then I believe it will last 200 hours as a simply voltage generator for an air/fuel ratio indicator without any problem. Just = that is just conjecture on my part as I have not tested it. =20 If you have sources on information to the contrary I would appreciate = if you would point me to them. =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 =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich Sent: Friday, October 16, 2009 9:38 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Stoich A/F Ratio?? : [FlyRotary] Re: where's = the missing power? =20 Ed, Yes the leaded gas was what I was alluding to. In the event unleaded = isn't available on trips, which I suspect will most likely be the case, the = wide band sensor will degrade and give false readings of air fuel ratios. Unless your just needing it for the initial set up!? George ( down under) George, not an expert on wide band sensors or narrow band for that = matter. =20 But, I do remember being told numerous times that even a few seconds = of running on leaded fuel would ruin the sensor. Well, it might for the purpose it is used in the automobile CPU as I expect the response time = slows down due to led fouling. But, response time that may be way too slow = for the CPU wouldn=92t even be notice by us Humans. I have over 160 hours = on narrow band O2 sensor running 100LL. =20 Now, here is a link to an article written by a gent who visited the = Bosch O2 sensor manufacturing plant in South Carolina. sessions on the dyno and limited use on track, but not for an entire racing season. http://www.superchevy.com/technical/engines_drivetrain/accessories_electr= oni cs/0407sc_bosch/index.html =20 Down about =BE down the article about the visit there is a summary of = Oxygen Sensor Facts - There he states that Bosch claims the wide band O2 = sensor will become degraded after about 200 hour of lead gas. =20 So, from that perspective and for our use as Air/Fuel ratio indicators, = it would appear to me that the wide band O2 sensor may be useful for our purposes. But, must admit I have not tried one out as yet. =20 Ed 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 =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich Sent: Friday, October 16, 2009 6:07 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Stoich A/F Ratio?? : [FlyRotary] Re: where's = the missing power? =20 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=92m 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 =96 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 =96 somewhere in the vicinity of 12 =96 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 =20 _____ =20 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 _____ =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=92m missing something - If your mixture monitor shows stoich = at full throttle, then it=92s not solely an airflow problem =96 it appears to me = that it=92s 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=92s an airflow problem when on the surface with the Stoich ratio it would = appear it=92s 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 =20 _____ =20 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 _____ =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=94 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 __________ 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_000C_01CA4EB0.9C6CB120 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Well, George, my take is the wide = band sensor would probably do fine just providing a voltage output which is = all we use for an air/fuel ratio indication.=A0 However, in a automobile = application they are using it to control the CPU and therefore the engine injectors = to keep the engine operating at the ratio of 14.7:1.=A0 As I understand it they = basically use a saw tooth wave form that’s centered around the 14.7:1 = voltage point and compare it to the output of the O2 sensor.=A0 The difference is used = to provide a indication to the CPU as to whether to enrich or lean the = mixture.

 

=A0 The lead in the gasoline = apparently =A0does not affect the voltage output, but does affect the response time of the = sensor to this varying voltage wave form – it slows it down to the point = it becomes unable to adequately control the CPU to maintain = 14.7:1.

 

So my take is the lead does not = apparently affect the voltage output of the sensor just slows it down too much to = be useful in its intended application.=A0 But, I could be incorrect in my understanding and about the effects of = lead.

 

However, IF Bosch claims it takes = 200 hours of leaded fuel =A0before the wide band is degraded to the point of not = being useful in its intended automobile application, then I believe it will = last 200 hours as a simply voltage generator for an air/fuel ratio indicator = without any problem.=A0 Just that is just conjecture on my part as I have not tested = it.

 

If=A0 you have sources on = information to the contrary I would appreciate if you would point me to = them.

 

Ed

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich
Sent: Friday, October 16, = 2009 9:38 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Stoich A/F Ratio?? : [FlyRotary] Re: where's the missing = power?

 

Ed,

Yes the leaded gas was what I was alluding to. In the = event unleaded isn't available on trips, which I suspect will most likely be = the case, the wide band sensor will  degrade and give false readings of = air fuel ratios.

Unless your just needing it for the initial set = up!?

George ( down under)

George, not an expert on wide band = sensors or narrow band for that matter.

 

  But, I do remember being = told numerous times that even a few seconds of running on leaded fuel would = ruin the sensor.  Well, it might for the purpose it is used in the = automobile CPU as I expect the response time slows down due to led fouling.  But, response time that may be way too slow for the CPU wouldn’t even = be notice by us Humans.  I have over 160 hours on narrow band O2 = sensor running 100LL.

 

Now, here is a link to an article = written by a gent who visited the Bosch O2 sensor manufacturing plant in = South = Carolina. sessions on the dyno and limited use on track, but not for = an entire racing season.

http://www.superchevy.com/technica= l/engines_drivetrain/accessories_electronics/0407sc_bosch/index.html<= o:p>

 

Down about =BE down the article = about the visit there is a summary of Oxygen Sensor Facts -  There he states = that Bosch claims the wide band O2 sensor will become degraded after about = 200 hour of lead gas.

 

So, from that perspective and for = our use as Air/Fuel ratio indicators, it would appear to me that the wide band = O2 sensor may be useful for our purposes.  But, must admit I have not = tried one out as yet.

 

Ed

From: = Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On Behalf Of George = Lendich
Sent: Friday, October 16, = 2009 6:07 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Stoich A/F Ratio?? : [FlyRotary] Re: where's the missing = power?

 

Ed,

Isn't the wide band sensor more prone to giving false readings ( corruption) due to = fouling.

George ( down under)

Hi = Bill,

 

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.  =

 

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.  =

  =

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. 

 

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.

 

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

 

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.

 

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

 

Ed

 

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?

 

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

 

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,

 

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. 

 

 

 

Ed.  =

 

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?

 

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.

 

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

 

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

 

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.

 

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.

 

Mike

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

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

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

 

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

 

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

 

Bill B

 

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.

 

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.

 

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



__________ 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

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