X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from sccrmhc13.comcast.net ([204.127.202.64] verified) by logan.com (CommuniGate Pro SMTP 4.3.6) with ESMTP id 613028 for flyrotary@lancaironline.net; Sat, 23 Jul 2005 20:18:38 -0400 Received-SPF: none receiver=logan.com; client-ip=204.127.202.64; envelope-from=n3773@comcast.net Received: from rv8 (c-24-21-140-241.hsd1.or.comcast.net[24.21.140.241]) by comcast.net (sccrmhc13) with SMTP id <20050724001753013008q97ue>; Sun, 24 Jul 2005 00:17:53 +0000 Message-ID: <006e01c58fe5$1fa66b10$f18c1518@rv8> Reply-To: "kevin lane" From: "kevin lane" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Lycoming debugging test - -HELP! Date: Sat, 23 Jul 2005 17:15:39 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0057_01C58FAA.260DFB70" 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 This is a multi-part message in MIME format. ------=_NextPart_000_0057_01C58FAA.260DFB70 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ed - I like this concept, that the flow is adequate for 1700rpm but not = 2200, and that the initial 2200 rpm lasts until the excess bowl fuel is = gone. I did notice that I when I bypassed the mechanical pump and ran = strictly off the facet that I could shut off the pump and nothing = changed for a while even though the fuel pressure was zero.(when running = at 900 rpm). I think it is time to check filters and pickup tubes, = which makes more sense to me than putting the second mag back on! you know, I've joked about never, ever in 7 years, 850 hrs., finding = any water in my fuel, since I keep the plane inside. what a killer if = all I needed was a damn fuel filter! my fuel pressure is measured right before it enters the carb. my = fuel system is tank(l/r), filter(l/r), fuel selector switch, fuel flow = meter, facet electric aux pump, mechanical pump, fuel pressure = regulator, fuel pressure meter, carb.(w/screen filter)(mp4spa). in theory then, if I ran the engine at say, 1700, it should never = cut out, or if at 2000 it should take longer to reach the starvation = point. heck of a time to be breaking in new rings, no? Kevin Lane Portland, OR e-mail-> n3773@comcast.net ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Saturday, July 23, 2005 4:55 PM Subject: [FlyRotary] Re: Lycoming debugging test - -HELP! 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_0057_01C58FAA.260DFB70 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
ed - I like this concept, = that the flow=20 is adequate for 1700rpm but not 2200, and that the initial 2200 rpm = lasts until=20 the excess bowl fuel is gone.  I did notice that I when I bypassed = the=20 mechanical pump and ran strictly off the facet that I could shut off the = pump=20 and nothing changed for a while even though the fuel pressure was = zero.(when=20 running at 900 rpm).  I think it is time to check filters and = pickup tubes,=20 which makes more sense to me than putting the second mag back = on!
    you know, = I've joked=20 about never, ever in 7 years, 850 hrs., finding any water in my fuel, = since I=20 keep the plane inside.  what a killer if all I needed was a damn = fuel=20 filter!
    my fuel = pressure is=20 measured right before it enters the carb.  my fuel system is = tank(l/r),=20 filter(l/r), fuel selector switch, fuel flow meter, facet electric aux = pump,=20 mechanical pump, fuel pressure regulator, fuel pressure meter, = carb.(w/screen=20 filter)(mp4spa).
    in theory = then, if I=20 ran the engine at say, 1700, it should never cut out, or if at 2000 it = should=20 take longer to reach the starvation point.  heck of a time to be = breaking=20 in new rings, no?
Kevin Lane  Portland, OR
e-mail-> n3773@comcast.net
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Saturday, July 23, 2005 = 4:55=20 PM
Subject: [FlyRotary] Re: = Lycoming=20 debugging test - -HELP!

Know next to nothing about Lycomings,=20 Kevin.
 
But, here are a few thoughts, you mention that = you can=20 get the drop on the ground if you run it a minute of so at full power = or in=20 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=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=20 to look at the fuel pumps or for a crimp/restriction  in the fuel = line=20 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=20 settings, the fuel being drawn out of the carb bowl may not be = replaced (by=20 your fuel line) at a rate sufficient to support 2000 rpm.  So = once your=20 fuel out of your carb bowl is drawn down to the sustainable lower fuel = flow=20 (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=20 I know nothing about Lycomings. 
 
Good Luck
 
Ed A
 
 
----- Original Message -----
From:=20 kevin = lane=20
To: Rotary motors in = aircraft=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. =20 mixture 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=20 a minute or so full power.  cht's will typically approach 415 = degrees=20 when the drop takes place.  I don't know if the temp is = significant or=20 not, it does seem that way.  I have a brand new slick left = mag. =20 rose checked the electronic ignition and could find nothing wrong, = even put=20 it in an oven to test.  I installed a new carb since the old = one showed=20 signs of leakage (and I'm at whits end).  no change.  my = fuel=20 pressure has been showing 8psi this last year, up from 6 psi when = originally=20 installed.(no idea why)  I installed a pressure regulator = in-line which=20 works like a charm.  I can dial whatever pressure I like.  = 2 psi=20 makes no difference.  I bypassed the mechanical fuel pump and = ran it=20 just on the facet electric.  2 psi, no difference. I = discovered=20 that you can run the carb for maybe 30 secs with no fuel pressure = while it=20 burns off the bowl gas. premier engines suggested induction leak = making the=20 engine run lean.  no leaks detected cold or hot engine. = (pressurized=20 intake with vacuum, sprayed soapy water)
    if the = engine=20 didn't run right to start with then many explanations would = hold.  but=20 it runs fine for several minutes.  it runs the same under mag = or=20 electronic ignition both before and after the problem kicks = in. =20 everyone really wants to blame the rose ignition, but I'm not seeing = any=20 connection.  with such a quick run-up my oil temp barely = registers, so=20 I doubt parts are seizing.  I have new mineral oil in it for = breakin=20 right now.  there is a bit of MMO in the fuel too I believe, = left over=20 from a mechanics "what the hell" attempt from way back.  my = cyls are=20 all new, rebuilts, so no valve problems.  I checked the push = rod=20 lengths when I reinstalled them.  the engine isn't missing = when=20 the problems occurs, it simply won't run faster and it seems to = prefer the=20 throttle pulled back to match the rpm it is putting out.  I = can't=20 figure out any more lean mixture scenarios to try.  the new = carb runs=20 just like the old one did.  I recently replaced the mag harness = with a=20 much newer, used one.  I tested it and it was fine.  the = plugs are=20 all new, but again, no diff between mag and elec ignition.  if = I flip=20 the ignition to R and shut off the elect ig then the engine quits as = would=20 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=20 have "cracked" cylinders, get out your microscope and look!).  = you guys=20 have any ideas?
Kevin Lane  Portland, OR
e-mail-> n3773@comcast.net
----- Original=20
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