X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTP id 5109010 for flyrotary@lancaironline.net; Tue, 30 Aug 2011 23:06:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=4MSDN839FDsgJpwQlr+eLEnlTy8eaQTddc4+Fk+GTfI= c=1 sm=0 a=fXmlKdHs-CIA:10 a=SC71y0a/4S6V9vjVxUojGA==:17 a=ayC55rCoAAAA:8 a=OBoQRNBVAAAA:8 a=N8B9JuSIAAAA:8 a=v9PXu11zf-wXof3kZokA:9 a=1fd_iA6e-7duposcTIcA:7 a=wPNLvfGTeEIA:10 a=pYEayob8caUA:10 a=-nZchTig-iG7GE8m:21 a=_6ryEPTZHqHyOd3o:21 a=Ia-xEzejAAAA:8 a=pGLkceISAAAA:8 a=0qOE7BNgcgV6jrlGsb0A:9 a=b9lZj8tsKFmAFmLlkk8A:7 a=EzXvWhQp4_cA:10 a=MSl-tDqOz04A:10 a=SC71y0a/4S6V9vjVxUojGA==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.175.135 Received: from [174.110.175.135] ([174.110.175.135:55583] helo=EdPC) by cdptpa-oedge03.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id A0/B6-28959-F25AD5E4; Wed, 31 Aug 2011 03:06:24 +0000 Message-ID: <20D45F2596464E1EB1175E8535D08D24@EdPC> From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Freq analysis of Knock sensor? Date: Tue, 30 Aug 2011 23:04:15 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0017_01CC6769.238668E0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0017_01CC6769.238668E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok, thanks Steve, got my legs mixed up - still a sexy bird Ed From: stevei@carey.asn.au=20 Sent: Tuesday, August 30, 2011 7:29 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Freq analysis of Knock sensor? Hi Ed, mines a Super II not a III. So the gear is not so tall.=20 Steve On 30/08/2011, at 10:13 PM, Ed Anderson wrote: That is one super aircraft - very sexy looking on that tall gear. = But, one heck of a lot of work. Let us all know when you have photos to share Ed From: stevei@carey.asn.au=20 Sent: Tuesday, August 30, 2011 10:06 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Freq analysis of Knock sensor? Hi Ed=20 I've had the engine running 18months ago but have it off the fuse so I = can rotate the thing for sanding.=20 I'm building a Glasair Super II RG. Just finishing the Slotted Flaps = at present. Hoping to put her together and retest engine by early next year. Sorry, not much help for now. Cheers Steve On 30/08/2011, at 7:50 PM, Ed Anderson wrote: Hi Steve, My understanding (Lynn will probably correct me here) is that under = normal loads, temps and fuel the probability of detonation or knock in a = rotary engine is pretty small due to the characteristics of its = combustion chamber. Now under boost, there is no question you can get = into the detonation range, so it would seem to me that a knock sensor = would be of biggest benefit to those with forced induction. =20 I , for one, would be very interested in what you find when you = listen in. Wonder whether you might be able to make an audio recording = of what the systems puts out - there are some interesting analytical = tools as pointed out by Finn and several others that might be = interesting to run the data through. I presume you have the engine running - just not up to full power, = yet? Ed From: stevei@carey.asn.au=20 Sent: Tuesday, August 30, 2011 4:38 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Freq analysis of Knock sensor? Hi Ed=20 My Renesis came with the knock sensor, but as you say the bandwidth = of the sensor is probably to wide. Having the sensor I built up a kit knock sensor amp and filters. But = as we recognise the knock of a rotor may sound vastly different from a = piston. I plan to listen in when I get to full power ground runs. Problem being I don't want to punish my engine to hear what it = sounds like when its complaining! Cheers Steve Izett On 29/08/2011, at 10:36 PM, Ed Anderson wrote: A thought occurred to me. If anyone has a spectrum analyzer = (Steve??) and could obtain an Rotary Knock sensor - that perhaps = determining the frequency response of the knock sensor MIGHT indicate = the frequency band pass required. Although it is likely to be too broad = to be much help if ( as likely) they do the filtering through a bandpass = filter within the engine CPU. Ed From: Ed Anderson=20 Sent: Monday, August 29, 2011 9:54 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Not so Simple was Knock sensor was tune with = ADI: [FlyRotary] Re: How to tune with ADI? As Tracy also indicated - in may cases, what initially appears = simple - frequently turns out not to be the case, when you dive into = the details.=20 Another seemingly simple project I thought about, was to add a = wide band O2 (WBO2) sensor option for the EFISM. This in order to = provide more accurate info on the air/fuel ratio (although one could = argue just how useful that might be for our applications). =20 While providing an algorithm for the different voltage input curve = of the WBO2 sensor (it is much more linear than the narrow band O2 = sensor curve) is straightforward, when you dive deeper you discover = that: 1. For the wide band O2 sensor to provide accurate information = the sensor temperature must be held within a critical narrow range. 2. To do this properly, the WBO2 manufacturer either programs = into the automobile's CPU or provides a separate "control" chip that = uses a PID (Proportional, Integral, derivative) the control algorithm = necessary to hold the required critical temperature range. 3. Failure to hold this temp range renders the sensor output of = questionable accuracy and will lead to degradation/failure of the = sensor. 4. The PID temp control is much more complex than the algorithm = required to read the output voltage=20 So while I could add the WBO2 sensor - without the separate = algorithm (or control chip), the validity of the data is uncertain and = likely misleading. So no WBO2 option any time soon. Yet this project is much more straightforward than a knock sensor. = Most automobile engine manufactures can afford to do the research and = they can spread the cost over millions of engines sold. As you might = imagine, the results of their R&D is considered proprietary information = and seldom available to the public. Ed From: Tracy=20 Sent: Monday, August 29, 2011 9:24 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: How to tune with ADI? What Ed said. There is a knock sensor input on the EC3 but after = finding the same facts as Ed mentioned, it takes a lot more R&D to = implement it so that's why it's currently unused. Tracy Sent from my iPad On Aug 29, 2011, at 8:33 AM, "Ed Anderson" = wrote: The problem with Knock sensors is that they need to be able to = identify the "knock" sound characteristic of the engine you have it on. = The circuit is basically simple - the challenge is design the = parameters of a signal filter that permits the circuit to properly = identify (filter) the "Knock" charactertistic of your particular engine. = =20 So I would suggest that a knock system for a rotary might have = different characteristics than for a piston engine. So what might work = fine for a piston engine might not work so well on a rotary. But, on = the other hand it might work fine. Ed From: stevei@carey.asn.au=20 Sent: Monday, August 29, 2011 3:45 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: How to tune with ADI? Hi Dave=20 If you are chasing a circuit for knock sensing try: http://siliconchip.com.au/cms/A_108910/article.html Cheers Steve Izett Perth WA On 29/08/2011, at 12:24 PM, David Leonard wrote: Ok, So I have the new ADI system installed and working.... I = think? Some of you smart racing guys probably have experience with = ADI. Most of the instructions that come with tuning it are directed = toward car guys that have computers and knock sensors. All they do is = turn the system on and the computer allows more advance because I is not = sensing any knock. The only real advise I have so for for me is that I = should be running just less than the amount of ADI that it takes to bog = down the engine. My system is a fixed flow so I don't have much choice = but it seems to be about right. If I use straight water (which I did = for initial testing), the engine bogs after about 10-15 seconds of = ruining the ADI system. But when I uses a 50/50 mix of water and = denatured alcohol (too hard to find methanol around here, but close = enough) the engine does not bog. So assuming my amount of ADI injected is about right, now I am = supposed to be able to lean to better power and advance the timing a = little. But how much? For the last testing flight I was using EGT for = lack of a better guide. When the ADI comes on, my EGT drops by about 30 = deg C, and there is a hint of roughness to the engine. I can then lean = a little and the roughness clears up. For my test flight I leaned until = my EFT came back up to where I normally limit it (890 deg C). But if I = then add 5 more inches of MAP, there is still a hint of roughness even = at 890 deg and I get the sense that it wants to be leaned a little more. = But I am afraid to do that... We are talking 45" MAP and 7300 RPM here = (185 KTS indicated (Vne) and climbing at 500 fpm). =20 So here are my questions: Is EGT a useful tool here, and does leaning to get the EGT = back to 890 make any sense? Since Methanol will do such a good job at preventing = detonation, is it safe to lean further toward best power (peak EGT)? = (note, that will be hard on the turbo... I need to remember to bring = the spare one to Reno) How much advance do you think i can add? I was previously = ruining 5 deg ahead of Tracy's recommended initial set up. Can't give a = number because the EC2 retards the timing with higher MAP's. How much, = I have not heard. I can easily add one deg at a time using Ed's EFI = monitor. But without a knock sensor am really in the blind. Thoughts? =20 --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net ------------------------------------------------------------------------ The contents of this email are confidential and intended only = for the named recipients of this e-mail. If you have received this = e-mail in error, you are hereby notified that any use, reproduction, = disclosure or distribution or the information contained in this e-mail = is prohibited. Please notify the sender immediately and then = delete/destroy the e-mail and any printed copies. All liability for = viruses is excluded to the fullest extent of the law. ------=_NextPart_000_0017_01CC6769.238668E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Ok, thanks Steve, got my legs mixed up - still a = sexy=20 bird
 
Ed

Sent: Tuesday, August 30, 2011 7:29 PM
Subject: [FlyRotary] Re: Freq analysis of Knock=20 sensor?

Hi Ed, mines a Super II not a III. So the gear is not so = tall.=20
Steve
On 30/08/2011, at 10:13 PM, Ed Anderson wrote:
That is one super aircraft - very sexy looking = on that=20 tall gear.  But, one heck of a lot of work.
 
Let us all know when you have photos to=20 share
 
Ed

Sent: Tuesday, August 30, 2011 10:06 AM
Subject: [FlyRotary] Re: Freq analysis of Knock=20 sensor?

Hi Ed=20
I've had the engine running 18months ago but have it off the fuse = so I=20 can rotate the thing for sanding. 
I'm building a Glasair Super II RG. Just finishing the Slotted = Flaps at=20 present.
Hoping to put her together and retest engine by early next = year.
Sorry, not much help for now.

Cheers

Steve

On 30/08/2011, at 7:50 PM, Ed Anderson wrote:
Hi Steve,
 
My understanding (Lynn will probably correct = me here)=20 is that under normal loads, temps and fuel the probability of = detonation or=20 knock in a rotary engine is pretty small due to the characteristics = of its=20 combustion chamber.  Now under boost, there is no question you = can get=20 into the detonation range, so it would seem to me that a knock = sensor would=20 be of biggest benefit to those with forced induction.  =
 
I , for one, would be very interested in = what you find=20 when you listen in.  Wonder whether you might be able to make = an audio=20 recording of what the systems puts out - there are some interesting=20 analytical tools as pointed out by Finn and several others that = might be=20 interesting to run the data through.
 
I presume you have the engine running - just = not up to=20 full power, yet?
 
Ed

Sent: Tuesday, August 30, 2011 4:38 AM
Subject: [FlyRotary] Re: Freq analysis of Knock=20 sensor?

Hi Ed=20

My Renesis came with the knock sensor, but as you say the = bandwidth of=20 the sensor is probably to wide.
Having the sensor I built up a kit knock sensor amp and = filters. But as=20 we recognise the knock of a rotor may sound vastly different from a=20 piston.
I plan to listen in when I get to full power ground runs.
Problem being I don't want to punish my engine to hear what it = sounds=20 like when its complaining!

Cheers

Steve Izett
On 29/08/2011, at 10:36 PM, Ed Anderson wrote:
A thought occurred to me.  If anyone = has a=20 spectrum analyzer (Steve??) and could obtain an Rotary Knock = sensor - that=20 perhaps determining the frequency response of the knock sensor = MIGHT=20 indicate the frequency band pass required.  Although it is = likely to=20 be too broad to be much help if ( as likely) they do the filtering = through=20 a bandpass filter within the engine CPU.
 
Ed

From: Ed=20 Anderson
Sent: Monday, August 29, 2011 9:54 AM
Subject: [FlyRotary] Not so Simple was Knock sensor = was tune=20 with ADI: [FlyRotary] Re: How to tune with ADI?

As Tracy also indicated - in may = cases,=20  what initially appears simple - frequently turns out = not to be=20 the case,  when you dive into the details. 
 
Another seemingly simple project I thought = about,=20 was to add a wide band O2 (WBO2) sensor option for the = EFISM. =20 This in order to provide more accurate info on the air/fuel = ratio=20 (although one could argue just how useful that might be for our=20 applications). 
 
While providing an algorithm for the = different=20 voltage input curve of the WBO2 sensor (it is much more = linear than=20 the narrow band O2 sensor curve) is straightforward, when you dive = deeper=20 you discover that:
 
1.  For the wide band O2 sensor to = provide=20 accurate information the sensor temperature must be held within a=20 critical narrow  range.
2.  To do this properly, the = WBO2 =20 manufacturer either programs into the automobile's  CPU or = provides a=20 separate "control" chip that uses a PID (Proportional, Integral,=20 derivative) the control algorithm necessary to hold the required = critical=20 temperature range.
3.  Failure to hold this temp range = renders the=20 sensor output of questionable accuracy and will lead to=20 degradation/failure of the sensor.
4.  The PID temp control is much more = complex=20 than the algorithm required to read the output voltage =
 
So while I could add the WBO2 sensor - = without the=20 separate algorithm (or control chip), the validity of the data is=20 uncertain and likely misleading.  So no WBO2 option any time=20 soon.
 
Yet this project is much more = straightforward than a=20 knock sensor.  Most automobile engine manufactures can afford = to do=20 the research and they can spread the cost over millions of engines = sold.  As you might imagine, the results of their R&D is=20 considered proprietary information and seldom available to the=20 public.
 
Ed
 
 

From: Tracy
Sent: Monday, August 29, 2011 9:24 AM
Subject: [FlyRotary] Re: How to tune with=20 ADI?

What Ed said.   There is a knock sensor input on the EC3 = but=20 after finding the same facts as Ed mentioned, it takes a lot more = R&D=20 to implement it so that's why it's currently unused.

Tracy

Sent from my iPad

On Aug 29, 2011, at 8:33 AM, "Ed Anderson" <eanderson@carolina.rr.com&g= t;=20 wrote:

The problem with Knock sensors is that = they need=20 to be able to identify  the "knock" sound characteristic of = the=20 engine you have it on.  The circuit is basically simple - = the=20 challenge is design the parameters of a signal filter that = permits the=20 circuit to properly identify (filter) the "Knock" = charactertistic=20 of your particular engine. 
 
So I would suggest that a knock system = for a=20 rotary might have different characteristics than for a piston=20 engine.  So what might work fine for a piston engine might = not work=20 so well on a rotary.  But, on the other hand it might work=20 fine.
 
Ed

From: stevei@carey.asn.au =
Sent: Monday, August 29, 2011 3:45 AM
Subject: [FlyRotary] Re: How to tune with=20 ADI?

Hi Dave=20
If you are chasing a circuit for knock sensing try:
http://silic= onchip.com.au/cms/A_108910/article.html

Cheers

Steve Izett
Perth WA
On 29/08/2011, at 12:24 PM, David Leonard wrote:
Ok,  So I have the new ADI system installed and=20 working....  I think?
 
Some of you smart racing guys probably have experience = with=20 ADI.
 
Most of the instructions that come with tuning it are = directed=20 toward car guys that have computers and knock sensors.  = All they=20 do is turn the system on and the computer allows more advance = because=20 I is not sensing any knock.  The only real advise I have = so for=20 for me is that I should be running just less than the amount = of ADI=20 that it takes to bog down the engine.  My system is a = fixed flow=20 so I don't have much choice but it seems to be about = right.  If I=20 use straight water (which I did for initial testing), the = engine bogs=20 after about 10-15 seconds of ruining the ADI system.  But = when I=20 uses a 50/50 mix of water and denatured alcohol (too hard to = find=20 methanol around here, but close enough) the engine does not = bog.
 
So assuming my amount of ADI injected is about right, now = I am=20 supposed to be able to lean to better power and advance the = timing a=20 little.  But how much?  For the last testing flight = I was=20 using EGT for lack of a better guide.  When the ADI comes = on, my=20 EGT drops by about 30 deg C, and there is a hint of roughness = to the=20 engine.  I can then lean a little and the roughness = clears=20 up.  For my test flight I leaned until my EFT came back = up to=20 where I normally limit it (890 deg C).  But if I then add = 5 more=20 inches of MAP, there is still a hint of roughness even at 890 = deg and=20 I get the sense that it wants to be leaned a little more. But = I am=20 afraid to do that...  We are talking 45" MAP and 7300 RPM = here=20 (185 KTS indicated (Vne) and climbing at 500 fpm).  =
 
So here are my questions:
Is EGT a useful tool here, and does leaning to get the = EGT back=20 to 890 make any sense?
Since Methanol will do such a good job at preventing = detonation,=20 is it safe to lean further toward best power (peak EGT)? = (note, that=20 will be hard on the turbo...  I need to remember = to bring=20 the spare one to Reno)
How much advance do you think i can add?  I was = previously ruining 5 deg ahead of Tracy's recommended = initial set=20 up.  Can't give a number because the EC2 retards the = timing=20 with higher MAP's.  How much, I have not heard.  I = can=20 easily add one deg at a time using Ed's EFI monitor.  But = without=20 a knock sensor am really in the blind.
 
Thoughts? 

--
David=20 Leonard

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


The contents of this = email are=20 confidential and intended only for the named recipients of this = e-mail.=20 If you have received this e-mail in error, you are hereby = notified that=20 any use, reproduction, disclosure or distribution or the = information=20 contained in this e-mail is prohibited. Please notify the sender = immediately and then delete/destroy the e-mail and any printed = copies.=20 All liability for viruses is excluded to the fullest extent of = the=20 = law.



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