X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3.6) with ESMTP id 613014 for flyrotary@lancaironline.net; Sat, 23 Jul 2005 19:55:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-065-188-083-049.carolina.res.rr.com [65.188.83.49]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j6NNscY5020177 for ; Sat, 23 Jul 2005 19:54:40 -0400 (EDT) Message-ID: <001701c58fe1$f7166220$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Lycoming debugging test - -HELP! Date: Sat, 23 Jul 2005 19:55:12 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0014_01C58FC0.6FB14AF0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0014_01C58FC0.6FB14AF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Know next to nothing about Lycomings, Kevin. But, here are a few thoughts, you mention that you can get the drop on = the ground if you run it a minute of so at full power or in the air = around 300'. Two thoughts come to mind - 1. Fuel flow problem 2. Temperature induced problem 3. 2 possibly causing 1. If you have adequate fuel to go with the air flow then power/rpm should = be maintained. So if the ignition is not the problem it would seem it = would have to be fuel flow. Where do you measure you fuel pressure? If = you are reading more fuel pressure now than previous, that could imply = fuel flow is less and therefore pressure is higher (before the = restriction). But, since it seems to act the same whether on 2 psi or = higher (although your message only mentions 2 psi) perhaps pressure is = not the key. Are your pumps in parallel or series? Could there be a = leak through or around one of the pumps. Have you tried it with both = pumps on? It sounds like to me that you are getting adequate fuel flow to support = 2000 rpm for a limited amount of time and then for some reason the fuel = flow decreases. Since you have changed the carb, I would tend to look = at the fuel pumps or for a crimp/restriction in the fuel line = someplace. For instance, if you had a fuel filter that was partially = plugged up at lower rpm (requiring less fuel flow), there might be = sufficient flow to support 1700 rpm continuously. However, at Higher = power settings, the fuel being drawn out of the carb bowl may not be = replaced (by your fuel line) at a rate sufficient to support 2000 rpm. = So once your fuel out of your carb bowl is drawn down to the sustainable = lower fuel flow (1700 rpm), the power drops off and fuel requirement = drops off to that supportable Level. Sure sounds like a fuel problem to = me, but then again I know nothing about Lycomings. =20 Good Luck Ed A ----- Original Message -----=20 From: kevin lane=20 To: Rotary motors in aircraft=20 Sent: Saturday, July 23, 2005 4:33 PM Subject: [FlyRotary] Lycoming debugging test - -HELP! I realize that this isn't exactly the right forum, but you guys seem = to have excellent debugging skills. my local RV group is totally = worthless ("I find the carnauba wax doesn't show fingerprints as much as = the....")(except Mike!) the on-field mechanics are sick of me coming = by. my O-320 RV-6A is having RAG (rpm attention getter) problems. it = runs fine until about 300' on take-off, then the rpm's drop to like 1700 = (from 2200). switching mags to electronic ignition(Rose) makes no = difference. mixture no diff. pulling the throttle it will seem to run = fine at 1700rpm. I have 4 new cyls that I am attempting to break in. = ground run ups can only go like 2 minutes before CHT's exceed 400 = degrees. I discovered I can get the rpm drop on the ground if I run it = a minute or so full power. cht's will typically approach 415 degrees = when the drop takes place. I don't know if the temp is significant or = not, it does seem that way. I have a brand new slick left mag. rose = checked the electronic ignition and could find nothing wrong, even put = it in an oven to test. I installed a new carb since the old one showed = signs of leakage (and I'm at whits end). no change. my fuel pressure = has been showing 8psi this last year, up from 6 psi when originally = installed.(no idea why) I installed a pressure regulator in-line which = works like a charm. I can dial whatever pressure I like. 2 psi makes = no difference. I bypassed the mechanical fuel pump and ran it just on = the facet electric. 2 psi, no difference. I discovered that you can run = the carb for maybe 30 secs with no fuel pressure while it burns off the = bowl gas. premier engines suggested induction leak making the engine run = lean. no leaks detected cold or hot engine. (pressurized intake with = vacuum, sprayed soapy water) if the engine didn't run right to start with then many = explanations would hold. but it runs fine for several minutes. it runs = the same under mag or electronic ignition both before and after the = problem kicks in. everyone really wants to blame the rose ignition, but = I'm not seeing any connection. with such a quick run-up my oil temp = barely registers, so I doubt parts are seizing. I have new mineral oil = in it for breakin right now. there is a bit of MMO in the fuel too I = believe, left over from a mechanics "what the hell" attempt from way = back. my cyls are all new, rebuilts, so no valve problems. I checked = the push rod lengths when I reinstalled them. the engine isn't missing = when the problems occurs, it simply won't run faster and it seems to = prefer the throttle pulled back to match the rpm it is putting out. I = can't figure out any more lean mixture scenarios to try. the new carb = runs just like the old one did. I recently replaced the mag harness = with a much newer, used one. I tested it and it was fine. the plugs = are all new, but again, no diff between mag and elec ignition. if I = flip the ignition to R and shut off the elect ig then the engine quits = as would be expected, no wiring problems. fuel, spark, air, timing, that's all there is. this damn lycoming = lawn mower has me stumped. my engine has been running fine up until = this (hey, we all have "cracked" cylinders, get out your microscope and = look!). you guys have any ideas? Kevin Lane Portland, OR e-mail-> n3773@comcast.net ----- Original ------=_NextPart_000_0014_01C58FC0.6FB14AF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Know next to nothing about Lycomings, = Kevin.
 
But, here are a few thoughts, you mention that = you can get=20 the drop on the ground if you run it a minute of so at full power or in = the air=20 around 300'.  Two thoughts come to mind -
 
1.  Fuel flow problem
2. Temperature induced problem
3. 2 possibly causing 1.
 
If you have adequate fuel to go with the air = flow then=20 power/rpm should be maintained.  So if the ignition is not the = problem it=20 would seem it would have to be fuel flow.  Where do you measure you = fuel=20 pressure?  If you are reading more fuel pressure now than previous, = that=20 could imply fuel flow is less and therefore pressure is higher (before = the=20 restriction).  But, since it seems to act the same whether on 2 psi = or=20 higher (although your message only mentions 2 psi) perhaps pressure is = not the=20 key.   Are your pumps in parallel or series? Could there be a = leak=20 through or around one of the pumps.  Have you tried it with both = pumps=20 on?
 
It sounds like to me that you are getting = adequate fuel=20 flow to support 2000 rpm for a limited amount of time and then for some = reason=20 the fuel flow decreases.  Since you have changed the carb, I would = tend to=20 look at the fuel pumps or for a crimp/restriction  in the fuel line = someplace.  For instance, if you had a fuel filter that was = partially=20 plugged up at lower rpm (requiring less fuel flow), there might be = sufficient=20 flow to support 1700 rpm continuously.  However, at Higher power = settings,=20 the fuel being drawn out of the carb bowl may not be replaced (by your = fuel=20 line) at a rate sufficient to support 2000 rpm.  So once your fuel = out of=20 your carb bowl is drawn down to the sustainable lower fuel flow (1700 = rpm), the=20 power drops off and fuel requirement drops off to that supportable = Level. =20 Sure sounds like a fuel problem to me, but then again I know nothing = about=20 Lycomings. 
 
Good Luck
 
Ed A
 
 
----- Original Message -----
From:=20 kevin = lane=20
Sent: Saturday, July 23, 2005 = 4:33=20 PM
Subject: [FlyRotary] Lycoming = debugging=20 test - -HELP!

I realize that this isn't = exactly the=20 right forum, but you guys seem to have excellent debugging = skills.  my=20 local RV group is totally worthless ("I find the carnauba wax doesn't = show=20 fingerprints as much as the....")(except Mike!)  the on-field = mechanics=20 are sick of me coming by.
    my O-320 = RV-6A is=20 having RAG (rpm attention getter) problems.  it runs fine until = about=20 300' on take-off, then the rpm's drop to like 1700 (from 2200). =20 switching mags to electronic ignition(Rose) makes no difference.  = mixture=20 no diff.  pulling the throttle it will seem to run fine at=20 1700rpm.  I have 4 new cyls that I am attempting to break = in. =20 ground run ups can only go like 2 minutes before CHT's exceed 400=20 degrees.  I discovered I can get the rpm drop on the ground if I = run it a=20 minute or so full power.  cht's will typically approach 415 = degrees when=20 the drop takes place.  I don't know if the temp is significant or = not, it=20 does seem that way.  I have a brand new slick left mag.  = rose=20 checked the electronic ignition and could find nothing wrong, even put = it in=20 an oven to test.  I installed a new carb since the old one showed = signs=20 of leakage (and I'm at whits end).  no change.  my fuel = pressure has=20 been showing 8psi this last year, up from 6 psi when originally = installed.(no=20 idea why)  I installed a pressure regulator in-line which works = like a=20 charm.  I can dial whatever pressure I like.  2 psi makes no = difference.  I bypassed the mechanical fuel pump and ran it just = on the=20 facet electric.  2 psi, no difference. I discovered that you = can run=20 the carb for maybe 30 secs with no fuel pressure while it burns off = the bowl=20 gas. premier engines suggested induction leak making the engine run=20 lean.  no leaks detected cold or hot engine. (pressurized intake = with=20 vacuum, sprayed soapy water)
    if the = engine didn't=20 run right to start with then many explanations would hold.  but = it runs=20 fine for several minutes.  it runs the same under mag or = electronic=20 ignition both before and after the problem kicks in.  everyone = really=20 wants to blame the rose ignition, but I'm not seeing any = connection. =20 with such a quick run-up my oil temp barely registers, so I doubt = parts are=20 seizing.  I have new mineral oil in it for breakin right = now.  there=20 is a bit of MMO in the fuel too I believe, left over from a mechanics = "what=20 the hell" attempt from way back.  my cyls are all new, rebuilts, = so no=20 valve problems.  I checked the push rod lengths when I = reinstalled=20 them.  the engine isn't missing when the problems occurs, it = simply won't=20 run faster and it seems to prefer the throttle pulled back to match = the rpm it=20 is putting out.  I can't figure out any more lean mixture = scenarios to=20 try.  the new carb runs just like the old one did.  I = recently=20 replaced the mag harness with a much newer, used one.  I tested = it and it=20 was fine.  the plugs are all new, but again, no diff between mag = and elec=20 ignition.  if I flip the ignition to R and shut off the elect ig = then the=20 engine quits as would be expected, no wiring problems.
    fuel, = spark, air,=20 timing, that's all there is.  this damn lycoming lawn mower has = me=20 stumped.  my engine has been running fine up until this (hey, we = all have=20 "cracked" cylinders, get out your microscope and look!).  you = guys have=20 any ideas?
Kevin Lane  Portland, OR
e-mail-> n3773@comcast.net
----- Original=20
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