Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2b3) with ESMTP id 100090 for flyrotary@lancaironline.net; Tue, 01 Jun 2004 21:28:11 -0400 Received: from EDWARD (clt25-78-058.carolina.rr.com [24.25.78.58]) by ms-smtp-01-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id i521RcfP022210 for ; Tue, 1 Jun 2004 21:27:39 -0400 (EDT) Message-ID: <003001c44840$cf1abf80$2402a8c0@EDWARD> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Power loss diagnostics Date: Tue, 1 Jun 2004 21:27:45 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_002D_01C4481F.47CB2C20" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_002D_01C4481F.47CB2C20 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageBoy, John after reading your offer of free fuel, room and beer - = I started packing - then I remembered my gearbox is at Tracy's for the = retrofit of the 2.85 {:<( and I am not inclined to drive, sorry. So John, difficult to make diagnostics from afar, but here goes. Some = of this is basic so don't be offended, often times that a good place to = start. 1. You need both fuel, spark and airflow to produce power. A = deficiency in one or all WILL reduce power (usually at the most critical = time {:>)). One thing that sort of bothers me about your installation = is that without boost you should be able to get a closer to 4500-4800 = rpm (A number of us get 5000 or more on take off). Now if you have a = lot of prop that of course could be part of the answer why your rpm is = lower and also why you do get that great acceleration. Actually, I am = impressed at how little power that canard takes to stay in the air. = 2500 rpm at 400 MSL on an 80F day would only give you around 70 HP! = without any boost. 2. Spark is generally either there and firing or not, so unless its = some problems with fouled plugs, I would for the moment eliminate them = as a cause. 3. That leaves fuel and air. I use SCATT tube and have never had it = collapse, you do have the type with the wire in it? If it did collapse, = reducing the throttle/airflow could allow it to open back up. Possible = cause, but you would generally see it do this at maximum rpm and boost = (max airflow) and I would think there would be some indication - like = loose wire in the tube, torn around the wire, I mean try collapsing a = length of it by hand - its not easy to do! Possible, but not at the top = of my list. 4. That leaves fuel. Fuel will certainly affect your power, anything = affecting fuel flow. Two things cross my mind. After you had coasted = down and landed (giving the engine some time to cool off in descent) I = believe you found you had regained your power. Now there are two reason = that come to mind. a. Could have had vapor lock. I read your story two times and I could = not find any place where you indicated you had checked your fuel = pressure (I might have just missed it). My experience has been anytime = my engine has had a problem with fuel its been reflected in the fuel = pressure gauge. Vapor lock generally shows up as fluctuating fuel = pressure. Could the heat generated by the climbout have caused = something like that whereby gliding back down give it time to cool down = again , so you again have throttle response on the ground. b. Could have been mixture. I sort of discount this one as if you are = flying and everything is stable engine wise, the fuel requirements (and = therefore mixture ) does not usually change abruptly enough to cause = that kind of power loss. If you want to discuss this further off line, just drop me a line or = give me a call 704-821-7595. Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ----- Original Message -----=20 From: John Slade=20 To: Rotary motors in aircraft=20 Sent: Tuesday, June 01, 2004 7:08 PM Subject: [FlyRotary] Re: Power loss diagnostics wrong again. My caps lock was on. Sorry. http://canardaviation.com/cozy/chap29.htm#diagnostics =20 ------=_NextPart_000_002D_01C4481F.47CB2C20 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Boy, John after reading your offer of = free fuel,=20 room and beer - I started packing - then I remembered my gearbox is = at=20 Tracy's for the retrofit of the 2.85 {:<( and I am not inclined to = drive,=20 sorry.
 
So John, difficult to make diagnostics = from afar,=20 but here goes.  Some of this is basic so don't be offended, often = times=20 that a good place to start.
 
1.  You need both fuel, spark and = airflow to=20 produce power.  A deficiency in one or all WILL reduce power = (usually at=20 the most critical time {:>)).  One thing that sort of bothers me = about=20 your installation is that without boost you should be able to get a = closer to=20 4500-4800 rpm (A number of us get 5000 or more on take off).  Now = if you=20 have a lot of prop that of course could be part of the answer why your = rpm is=20 lower and also why you do get that great acceleration.  Actually, I = am=20 impressed at how little power that canard takes to stay in the = air.  2500=20 rpm at 400 MSL on an 80F day would only give you around 70 HP! without = any=20 boost.
 
2.  Spark is generally either = there and firing=20 or not, so unless its some problems with fouled plugs, I would for the = moment=20 eliminate them as a cause.
 
3. That leaves fuel and air.  I = use SCATT tube=20 and have never had it collapse, you do have the type with the wire in = it? =20 If it did collapse, reducing the throttle/airflow could allow it to open = back=20 up. Possible cause, but you would generally see it do this at maximum = rpm and=20 boost (max airflow) and I would think there would be some = indication - like=20 loose wire in the tube, torn around the wire, I mean try collapsing a = length of=20 it by hand - its not easy to do! Possible, but not at the top of my=20 list.
 
4.  That leaves fuel.  Fuel = will=20 certainly affect your power, anything affecting fuel flow.  Two = things=20 cross my mind.  After you had coasted down and landed (giving the = engine=20 some time to cool off in descent) I believe you found you had regained = your=20 power.  Now there are two reason that come to mind.
 
a.  Could have had vapor = lock.  I read=20 your story two times and I could not find any place where you indicated = you had=20 checked your fuel pressure (I might have just missed it).  My = experience=20 has been anytime my engine has had a problem with fuel its been = reflected in the=20 fuel pressure gauge.  Vapor lock generally shows up as fluctuating = fuel=20 pressure.  Could the heat generated by the climbout have caused = something=20 like that whereby gliding back down give it time to cool down again , so = you again have throttle response on the ground.
 
b.  Could have been mixture.  = I sort of=20 discount this one as if you are flying and everything is stable engine = wise, the=20 fuel requirements (and therefore mixture ) does not usually change = abruptly=20 enough to cause that kind of power loss.
 
If you want to discuss this further off = line, just=20 drop me a line or give me a call 704-821-7595.
 
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
----- Original Message -----
From:=20 John=20 Slade
Sent: Tuesday, June 01, 2004 = 7:08=20 PM
Subject: [FlyRotary] Re: Power = loss=20 diagnostics

wrong again. My caps lock was on. Sorry.
 
    =20 http://canardaviation.com/cozy/chap29.htm#diagnostics  
&nbs= p;
 
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