X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.25.9.100] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with ESMTP id 2043354 for flyrotary@lancaironline.net; Mon, 14 May 2007 09:09:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-01.southeast.rr.com (8.13.6/8.13.6) with SMTP id l4ED87vH027896 for ; Mon, 14 May 2007 09:08:08 -0400 (EDT) Message-ID: <003001c79629$234d1bf0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Air Measurement Approach Date: Mon, 14 May 2007 09:09:42 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01C79607.9BD9D3F0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_002D_01C79607.9BD9D3F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable The solution Lynn is the hot wire mass flow sensor. I'm not sure if = Tracy could incorporate one in place of the map sensor. The circuitry = may be more complicated. There are comercial versions available fro use = with many of the throttle bodies. A single P-port inlet tube without an = air box poses a real problem. Some of the older mechanical systems are = easier to work with on single tube openings. Many of the bikes used an = alpha-n system measuring only throttle opening RPM and had a sensor for = speed, usually at the rear sprocket. The needed injector map was VERY = complex and hard to modify. True mass flow would be better. I wonder = what the LeMans 26B used?=20 Bill Jepson =20 No doubt that Tracy could design a injection system that uses a mass = flow sensor - after all, as you know, the system only wants to know = (and doesn't care how) how much air mass is in the combustion chamber = in order to determine the fuel to meet your desired A/F ratio. However, unless there was some significant market demand for such, = I doubt it would be worth his investment to do so. I have not given it = any thought, but there might be reliability/safety issues using a air = mass flow sensor vice a manifold pressure sensor in aircraft = application.=20 For one thing it would be a bit more of a hassle to have two air = flow sensors (for redundancy) spacewise and perhaps plumbing wise (air) = than with the two pressure sensor. -The pressure sensor can be stuck any = place including inside the EC2 box in the cockpit area with just two = small hoses running to them - not so with two air mass flow sensors. =20 The Alpha-N system based on Throttle position and rpm might be more = suitable, but as Bill indicated the fuel map might be more complex as = there would be no direct indication of engine load such as manifold = pressure or air flow would give. Another challenge would be to have a = Throttle position sensor which would be compatible with all the variety = of TB that folks use. So it certainly could be done, but unless there was some market = demand for it, I don't foresee it coming. Just my 0.02 worth and I certainly don't speak for Tracy Ed Ed ------=_NextPart_000_002D_01C79607.9BD9D3F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 The solution Lynn is the hot wire mass = flow=20 sensor. I'm not sure if Tracy could incorporate one in place of the map = sensor.=20 The circuitry may be more complicated. There are comercial versions = available=20 fro use with many of the throttle bodies. A single P-port inlet tube = without an=20 air box poses a real problem. Some of the older mechanical systems are = easier to=20 work with on single tube openings. Many of the bikes used an alpha-n = system=20 measuring only throttle opening RPM and had a sensor for speed, usually = at the=20 rear sprocket. The needed injector map was VERY complex and hard to = modify. True=20 mass flow would be better. I wonder what the LeMans 26B used? =
Bill Jepson
 
 
No doubt that Tracy could design a injection = system that=20 uses a mass flow sensor - after all, as you know,  the system = only=20 wants to know (and doesn't care how)  how much air mass is in = the=20 combustion chamber in order to determine the fuel to meet your = desired A/F=20 ratio.
 
However, unless there was some significant =  market=20 demand for such, I doubt it would be worth his investment to do = so.  I=20 have not given it any thought, but there might be reliability/safety = issues=20 using a air mass flow sensor vice a manifold pressure sensor in = aircraft=20 application. 
 
 For one thing it would be a bit more of a = hassle to=20 have two air flow sensors (for redundancy) spacewise and perhaps = plumbing=20 wise (air) than with the two pressure sensor. -The pressure sensor = can be=20 stuck any place including inside the EC2 box in the cockpit area = with just=20 two small hoses running to them - not so with two air mass flow = sensors. 
 
The Alpha-N system based on Throttle position = and rpm=20 might be more suitable, but as Bill indicated the fuel map = might be=20 more complex as there would be no direct indication of engine load = such as=20 manifold pressure or air flow would give.  Another challenge = would be=20 to have a Throttle position sensor which would be compatible with = all the=20 variety of TB that folks use.
 
  So it certainly could be done, but unless = there was=20 some market demand for it, I don't foresee it coming.
 
Just my 0.02 worth and I certainly don't speak = for=20 Tracy
 
Ed
 
Ed
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