X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from m12.lax.untd.com ([64.136.30.75] verified) by logan.com (CommuniGate Pro SMTP 4.3.6) with SMTP id 618353 for flyrotary@lancaironline.net; Thu, 28 Jul 2005 17:20:01 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.30.75; envelope-from=alwick@juno.com Received: from m12.lax.untd.com (localhost [127.0.0.1]) by m12.lax.untd.com with SMTP id AABBQUU7AAQ23LXS for (sender ); Thu, 28 Jul 2005 14:18:24 -0700 (PDT) X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkBLqSg0lhsyV26B3upmmAKi3qUI/thTU9w== Received: (from alwick@juno.com) by m12.lax.untd.com (jqueuemail) id KY2BYE42; Thu, 28 Jul 2005 14:17:26 PDT To: flyrotary@lancaironline.net Date: Thu, 28 Jul 2005 14:17:04 -0700 Subject: Re: [FlyRotary] Re: fuel filter question Message-ID: <20050728.141712.2552.4.alwick@juno.com> X-Mailer: Juno 5.0.33 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=--__JNP_000_4498.130a.48ed X-Juno-Line-Breaks: 8-6,12-13,17-18,21-22,24-35,37-39,46-52,54-59,69,76,78-79,80-32767 From: al p wick X-ContentStamp: 26:13:1104664484 X-MAIL-INFO:17e5e5c0200059a0e4b0f9c0f1f94934842910f909d9a1602009102909fd09e99099443de5a5c0cdc09520ad49dd8dada00075994df5e159f9a4615061b4f5b4a454240435fded5d00e5d094d115412155355534e130f419dded5d74b5b585392515ad7111a181d49438b98d50c96199c109d501d910cd75840d91 X-UNTD-Peer-Info: 127.0.0.1|localhost|m12.lax.untd.com|alwick@juno.com This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ----__JNP_000_4498.130a.48ed Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Most of you know that vapor lock is directly caused by low pressure on the inlet side of fuel pump. There are a number of design oversights that will increase your risk. Among them is the inlet filter. It causes pressure drop. As does fuel flow meter, diameter of fuel line, pump temperature, head pressure, inadequate fuel vent, fuel type, altitude, flight attitude, fuel temp. This is one of the few design features that truly is complicated. You can't just follow someone else and assume you are ok. It's the fine details of your fuel design that makes a difference. YOU CAN'T JUST RUN YOUR PLANE ON THE GROUND AND ASSUME YOU ARE NOT AT RISK. I use a large filter bag on one inlet. Nothing on the other inlet. The large bag is self cleaning, has huge surface area, little pressure drop. It's used by the auto manufacturer. Please investigate thoroughly and resist assumptions. Your life depends on it. regards -al wick Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5 N9032U 200+ hours on engine/airframe from Portland, Oregon Prop construct, Subaru install, Risk assessment, Glass panel design info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Thu, 28 Jul 2005 12:44:23 -0500 "Bobby J. Hughes" writes: Kevin, I have know idea why EFI filters cannot be used on the low pressure side as long as they do not restrict flow. Hopefully someone will chime in with the facts. I am planning on using EFI filters before my pumps also. They are the same ones that Ed and others are running on the high pressure side. They have a large 16mm in and out. AC Delco GF652. I believe the Egg subi's are also running these filters on the low pressure side. Bobby From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of kevin lane Sent: Thursday, July 28, 2005 11:44 AM To: Rotary motors in aircraft Subject: [FlyRotary] fuel filter question I suspect that my engine problems stem from a design flaw, rather than a blockage. I normally never run my engine full power, full rich, but have been while breaking in the new rings. even leaning the engine a few notches prevents my problem, so it never arose in the past. my auto fuel filters are on the "suck" side, between the tanks and the selector valve. they are small, glass see-thru mesh filters. I realize now that all the fuel passes thru a pair of like 1/8" holes from a common 1/4" passage. I also see that the facet pump, despite pumping 15+ gals / hr with no head pressure, will only produce 1.75 lbs pressure when attached to the carb and bypassing the manual pump. my question - I was told not to use a fuel injection filter on a low pressure system like mine. I would like to keep the filters where they are rather than moving them to the engine compartment, since they filter stuff ahead of my flow meter and pumps. I like how they fit along the wing spar below my knees. I had problems with the replaceable filters shedding fibers into the carb, which is why I changed to the mesh filters. does anyone know what I should be using? I plan to do more testing this weekend if my wife will let me drive her car("no, I'm not feeling sleepy :-)" to get to the airport. Kevin Lane Portland, OR e-mail-> n3773@comcast.net ----__JNP_000_4498.130a.48ed Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: quoted-printable
Most of you know that vapor lock is directly caused by low pressure on= the=20 inlet side of fuel pump. There are a number of design oversights = that=20 will increase your risk. Among them is the inlet filter. It causes pressure= =20 drop. As does fuel flow meter, diameter of fuel line, pump temperature, = head=20 pressure, inadequate fuel vent, fuel type, altitude, flight attitude, fuel = temp.=20
 
This is one of the few design features that truly is complicated. You = can't=20 just follow someone else and assume you are ok. It's the fine details of = your=20 fuel design that makes a difference. YOU CAN'T JUST RUN YOUR PLANE ON THE = GROUND=20 AND ASSUME YOU ARE NOT AT RISK.
 
I use a large filter bag on one inlet. Nothing on the other inlet. The= =20 large bag is self cleaning, has huge surface area, little pressure drop. It= 's=20 used by the auto manufacturer.
 
Please investigate thoroughly and resist assumptions. Your life = depends on=20 it.
 
regards
 

-al wick
Artificial intelligence in cockpit, Cozy IV powered by= =20 stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland,=20 Oregon
Prop construct, Subaru install, Risk assessment, Glass panel = design=20 info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
 
On Thu, 28 Jul 2005 12:44:23 -0500 "Bobby J. Hughes" <bhughes@qnsi.net> writes:
Kevin,
 
I have know idea why EFI filters cannot be used = on the=20 low pressure side as long as they do not restrict flow. Hopefully someone= will=20 chime in with the facts. I am planning on using EFI filters before my = pumps=20 also. They are the same ones that Ed and others are running on the high=20 pressure side. They have a large 16mm in and out. AC Delco GF652. I = believe=20 the Egg subi's are also running these filters on the low pressure=20 side.
 
Bobby

From: Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On Behalf Of kevin=20 lane
Sent: Thursday, July 28, 2005 11:44 AM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] fuel filter=20 question

I suspect that my engine = problems stem=20 from a design flaw, rather than a blockage.  I normally never run my= =20 engine full power, full rich, but have been while breaking in the new=20 rings.  even leaning the engine a few notches prevents my problem, = so it=20 never arose in the past.  my auto fuel filters are on the "suck" = side,=20 between the tanks and the selector valve.  they are small, glass see= -thru=20 mesh filters.  I realize now that all the fuel passes thru a pair of= like=20 1/8" holes from a common 1/4" passage.  I also see that the facet = pump,=20 despite pumping 15+ gals / hr with no head pressure, will only produce 1.= 75=20 lbs pressure when attached to the carb and bypassing the manual=20 pump.
    my question= - I was=20 told not to use a fuel injection filter on a low pressure system like=20 mine.  I would like to keep the filters where they are rather than = moving=20 them to the engine compartment, since they filter stuff ahead of my flow = meter=20 and pumps.  I like how they fit along the wing spar below my knees.&= nbsp;=20 I had problems with the replaceable filters shedding fibers into the carb= ,=20 which is why I changed to the mesh filters.   does anyone know = what=20 I should be using?
    I plan to = do more=20 testing this weekend if my wife will let me drive her car("no, I'm not = feeling=20 sleepy :-)" to get to the airport.
Kevin Lane  Portland, OR
e-mail-> n3773@comcast.net
 
 
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