X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3433581 for flyrotary@lancaironline.net; Mon, 19 Jan 2009 11:29:23 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from computername ([75.191.186.236]) by cdptpa-omta01.mail.rr.com with ESMTP id <20090119162845.XZPF16090.cdptpa-omta01.mail.rr.com@computername> for ; Mon, 19 Jan 2009 16:28:45 +0000 From: "Ed Anderson" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Paul Lamar's Simple Fuel Injection Date: Mon, 19 Jan 2009 11:28:52 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001B_01C97A29.1B6213B0" X-Mailer: Microsoft Office Outlook, Build 11.0.5510 thread-index: Acl6HfPR1nFZfdGGQY+zWCSoV583SgAHYxMg X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 In-Reply-To: Message-Id: <20090119162845.XZPF16090.cdptpa-omta01.mail.rr.com@computername> This is a multi-part message in MIME format. ------=_NextPart_000_001B_01C97A29.1B6213B0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Michael, many on this list do not monitor Paul's list. Regarding the 555 injector. The amount of fuel need to support combustion at a specific Air/Fuel Ratio is dependent on two major factors. These two factors are the size of the combustion chamber and the density of the air in the combustion chamber. The role rpm plays is the number of times the chamber is filled and emptied per unit time. Since the displacement (size) of the combustion chamber is fixed that then means the fuel required (over time) is a function of both air density and RPM. Air density can be inferred as a function of either air mass flow or manifold pressure (the two most common approaches to determining engine load). But, in either case, air mass flow and/or manifold pressure is a function of rpm AND engine Load. Lets not forget also it is also a function of ambient pressure and air temperature as well. The two most popular methods of controlling the fuel injected are based on either a measurement of air flow (the method proposed in the article) or the measurement of manifold pressure (reflecting air density). Either method will work. One requires the air to flow fairly cleanly through an air mass flow meter (such as one the Paul showed used to Lean the injector to more closely match the airflow demands of the engine) the other approach normally uses a pressure sensor to measure the manifold pressure. As I said they both work. For example, instead of using an airflow meter, you could simply use an appropriate range (10-30"Hg) manifold pressure sensor with an output from 1 - 5 volts and hook it up the same way as Paul indicates hooking up the air flow sensor to "lean" the fuel injector for cruise. Now when it comes to using one in an aircraft, I personally prefer the air density (manifold pressure) approach. It does not require any mass flow meter - you can use any throttle body you want. If your TB of preference does not have an integrated mass flow meter then you will need to place one in the air flow circuit after the TB. With the air density approach, there is no sensing device in the airflow and the manifold sensor can be attached to the manifold at any number of locations or a remote location connected with a hose. Then there is the question of redundancy. I personally had a HALTECH EFI system with which I had flown approx 160 hours fail on me - fortunately on the ground. That is one of the major reasons, I switched to Tracy Crook's EC2 - it has two independent controllers. So, it really depends on what you are looking for. There is no question that a unit like this could be put together rather inexpensively - but, I personally prefer something a bit more sophisticated and with some redundancy. Just my personal viewpoint. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Michael McMahon Sent: Monday, January 19, 2009 5:07 AM To: Rotary motors in aircraft Subject: [FlyRotary] Paul Lamar's Simple Fuel Injection I haven't seen any response on this list to the article that Paul Lamar posted a couple days ago (below). I'm very interested in objective discussion of merits and flaws, and there hasn't been much on the Rotary Engines list. Has anyone read it? Any opinions? Thanks, Michael >>>> Not entirely done as I will be updating it from time to time depending on your questions. >>>> http://www.rotaryeng.net/simple-cheap-555.html >>>> Paul Lamar -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html __________ 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_001B_01C97A29.1B6213B0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Michael, many on this list do not monitor Paul's = list.

 

Regarding the 555 injector.

 

The amount of fuel need to support combustion at a specific = Air/Fuel Ratio is dependent on two major factors. These two factors are the size = of the combustion chamber and the density of the air in the combustion = chamber.  The role rpm plays is the number of times the chamber is filled and = emptied per unit time.  Since the displacement (size) of the combustion chamber = is fixed that then means the fuel required (over time) is a function of = both air density and RPM. Air density can be inferred as a function of either air = mass flow or manifold pressure (the two most common approaches to determining = engine load).

 

But, in either case, air mass flow and/or manifold pressure is a function of rpm AND engine Load. Lets not forget also it is also a = function of ambient pressure and air temperature as = well.

 

The two most popular methods of controlling the fuel injected = are based on either a measurement of air flow (the method proposed in the article) = or the measurement of manifold pressure (reflecting air density).  Either = method will work.  One requires the air to flow fairly cleanly through an = air mass flow meter (such as one the Paul showed used to Lean the injector = to more closely match the airflow demands of the engine) the other approach = normally uses a pressure sensor to measure the manifold pressure.   As = I said they both work.  For example, instead of using an airflow meter, = you could simply use an appropriate range (10-30”Hg) manifold pressure = sensor with an output from 1 – 5 volts and hook it up the same way as Paul = indicates hooking up the air flow sensor to “lean” the fuel injector = for cruise.

 

Now when it comes to using one in an aircraft, I personally = prefer the air density (manifold pressure) approach.  It does not require any = mass flow meter – you can use any throttle body you want.  If your = TB of preference does not have an integrated mass flow meter then you will = need to place one in the air flow circuit after the TB.  With the air = density approach, there is no sensing device in the airflow and the manifold = sensor can be attached to the manifold at any number of locations or a remote = location connected with a hose.

 

Then there is the question of redundancy.  I personally had = a HALTECH EFI system with which I had flown approx 160 hours fail on me = – fortunately on the ground.  That is one of the major reasons, I = switched to Tracy Crook’s EC2 – it has two independent = controllers.

So, it really depends on what you are looking for.  There = is no question that a unit like this could be put together rather = inexpensively – but, I personally prefer something a bit more sophisticated and with = some redundancy.  Just my personal = viewpoint.

 

Ed

 

 

 

Ed Anderson

 

Rv-6A N494BW Rotary Powered

 

Matthews, NC

 

eanderson@carolina.rr.com

 

http://www.andersonee.com

 

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

 

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

 

-----Original Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Michael McMahon
Sent: Monday, January 19, 2009 5:07 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Paul Lamar's Simple Fuel = Injection

 

I haven't seen any response on this list to the article that = Paul Lamar

posted a couple days ago (below).  I'm very interested in objective

discussion of merits and flaws, and there hasn't been much on = the Rotary

Engines list.   Has anyone read it?  Any = opinions?

 

Thanks,  Michael

 

>>>> Not entirely done as I will be updating it from = time to time depending

on your questions.

>>>> = http://www.rotaryeng.net/simple-cheap-555.html

>>>> Paul Lamar

 

 

--

Homepage:  = http://www.flyrotary.com/

Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html

 

__________ 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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