X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao101.cox.net ([68.230.241.45] verified) by logan.com (CommuniGate Pro SMTP 5.3.4) with ESMTP id 4165046 for flyrotary@lancaironline.net; Sat, 13 Mar 2010 23:04:22 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.45; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao101.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20100314040346.ZXTL4995.fed1rmmtao101.cox.net@fed1rmimpo02.cox.net> for ; Sat, 13 Mar 2010 23:03:46 -0500 Received: from willsPC ([68.105.86.80]) by fed1rmimpo02.cox.net with bizsmtp id ss3j1d00F1k005Q04s3jrA; Sat, 13 Mar 2010 23:03:43 -0500 X-VR-Score: -130.00 X-Authority-Analysis: v=1.1 cv=KqzZVGv1/pIBe+XbL3gCBfL8vaFXECOST7Bs1vfp5Gs= c=1 sm=1 a=GkVrOFAuG9wA:10 a=XruvlouZCDbGUgEaRUiNZQ==:17 a=kviXuzpPAAAA:8 a=ayC55rCoAAAA:8 a=arxwEM4EAAAA:8 a=QdXCYpuVAAAA:8 a=7g1VtSJxAAAA:8 a=ekHE3smAAAAA:20 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=3oc9M9_CAAAA:8 a=nUuTZ29dAAAA:8 a=WHbK2rQXXRDplBz7e0cA:9 a=JaCEL7OVRWAhEvXSvkAA:7 a=IpQUxZuyu9DNLnZH3oMVGMTNFXMA:4 a=pILNOxqGKmIA:10 a=1vhyWl4Y8LcA:10 a=4vB-4DCPJfMA:10 a=EzXvWhQp4_cA:10 a=U8Ie8EnqySEA:10 a=pLgnmdyYzV2jkvdn:21 a=plJBazKoF6SaaNC-:21 a=NH0jtXDhs6kRPHn5d68A:9 a=oxg7RNeHJGHl5HdpY00A:7 a=6GMUz5U4GH4kqfOzEhKVxOap7qcA:4 a=iVkDmfvjeKcA:10 a=MASoPf4US91uJTIH:21 a=A8qWkaNqtHE7pXo_:21 a=XruvlouZCDbGUgEaRUiNZQ==:117 X-CM-Score: 0.00 Message-ID: <3FF6CBCF5B2B4E9A9A9B5B3841FAAF35@willsPC> From: "Mike Wills" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: fuel supply problem? Date: Sat, 13 Mar 2010 20:03:42 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_004A_01CAC2E8.479D8FF0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8089.726 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8089.726 This is a multi-part message in MIME format. ------=_NextPart_000_004A_01CAC2E8.479D8FF0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Tracy, I do have filters between tanks and pumps. I had an issue early on with = junk in the filters but never enough to cause any issue. This was just a = little construction debris and remnants of some automotive sealant I = initially used to install the access plates (since reinstalled with = Proseal). I just did my first condition inspection and checked the = filters about a month ago and they were clean. But I will check them = again. Never have had a problem previously with pressure drop across the = filter. The problem happened at about the 1.3 hour point in the flight. = At the time I was motoring around at 8500' and at a pretty low power = setting - EFISM said fuel flow was about 7.8 GPH. I did run it up to = full power on the ground and couldn=92t duplicate. My pickups have a screen and have the Vans required anti-rotation tab = riveted to the access cover plate. But I suppose if I cant attribute it = to anything else I should probably pull the tank and make sure the = pickup hasn=92t moved. Man that sounds like a lot of work. Mike =20 From: Tracy Crook=20 Sent: Saturday, March 13, 2010 10:35 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: fuel supply problem? I had a similar thing happen but the engine would recover when I reduced = throttle. Problem was clogged filter between tank and pump. At low = flow rate all was OK but pressure drop across filter at high flow rate = caused pump to cavitate and fuel pressure to drop. Did you try high = throttle on ground test later? But you didn't mention a filter between tank & pump. That has potential = problems as well since it doesn't take much trash to foul up an EFI pump = & might have cleared up after it passed. Do you have only the slots in = Van's suggested tank pickup between tank & pump? Problem might have = been trash going through pump. I guess Ed already mentioned the loose tank pickup problem he had. Tracy On Sat, Mar 13, 2010 at 11:29 AM, Mike Wills wrote: I'm pretty sure the turn was coordinated. Knowing that both tanks were = approaching (if not below) 5 gallons, it was the first thing I thought = of and I looked at the ball. It was centered. And I'm sure there is = going to turn out to be about 5 gallons left in the tank so its hard to = understand how this could have been an issue with the pickup uncovering. = I just don=92t have a better explanation. If the pump failed I would = expect it to stay failed, not work fine on the ground. I didn=92t copy it, but my system I believe is the same that Ian = Beadle used. I have 1 pump for each tank. The outputs are T'eed together = - check valves built into the pumps prevents crossfeed. Both tanks have = return lines. The return line from the fuel rail goes through an = industrial grade electric valve. I chose this design for a couple of reasons: 1) Operational simplicity. I reasoned that most fuel related problems = in flight are due to stupid pilot tricks so wanted a system that was as = simple to operate as possible. In its original configuration all that = was required to switch tanks was to flip a single toggle switch on the = panel which would energize the appropriate pump and configure the return = valve to return fuel to the tank it came from. This has since been = modified slightly to have individual switches for each pump so both can = be on at the same time if needed. 2) I had previous experience (bad) with EFI in some project cars = before I built the airplane. I had a couple of fuel pump failures and in = researching found strong recommendations against putting the fuel pump = too far from the fuel tank. These pumps are designed to push fuel, not = draw fuel. A design where both pumps have access to both tanks requires = the pumps to be downstream of the fuel selector with several feet of = fuel line ahead of the pump. I wanted to avoid this type of design = although it apparently is working fine for Ed. My pumps are just inboard = of the wing roots literally a couple of inches from the pickups in the = tanks. Tracy's system is mechanically simple but has the potential for pilot = error resulting in pumping fuel overboard if the transfer pump is = forgotten and left on. Yes, I know there are ways to address that. And = clearly it works for him. I think (thought?) I pretty well understand the pros and cons in my = setup. All things being equal I think before yesterday's incident I = would do it this way again. If it turns out that the issue was due to = uncovering the pickup (not real sure how to prove that) I'd consider = changing to include a header tank with a deep sump to prevent = re-occurance. But I don=92t think I'd rely on suction to fill the = header, think I'd use a low pressure pump like the typical Facet pump. One thing is for certain. Unlike a carbureted engine which has a = little cushion due to fuel in a float bowl, the instant fuel pressure = drops this engine quits. It's an attention getter. Particularly when you = are at the opposite corner of your test box from your home base. I ended = up flying back about 70 miles hopscotching from field to field. Mike=20 From: Ed Anderson=20 Sent: Saturday, March 13, 2010 1:53 AM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: fuel supply problem? There is certainly more than one way to design a reliable fuel system = =96 each with its pros and cons. I too did not want a six way value for = switching fuel between two tanks and the engine with the ugh return = line. Besides I had already constructed my fuel system pretty much = according to Van=92s instructions. So to preclude a return line I came = up with my =93almost returnless=94 system. It uses a =BD pint capacity = small header tank to return the injector fuel =96 the fuel injected to = the engine comes from this header tank thereby creating a =93vacuum=94 = in the tank which pulls fresh fuel from the wing tanks. It has worked = fine for over 10 years. Both fuel pumps draw from this header tank and either tank can feed it = and I have no return lines going back to the tanks. But, Tracy=92s approach has shown to work just fine =96 not knocking = it by any means. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Bktrub@aol.com Sent: Friday, March 12, 2010 11:43 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: fuel supply problem? I just copied Tracy's setup- all fuel is pumped from the right tank, = and fuel is transferred from the left into the right by a Facet pump. I = didn't want to get into having a six port fuel valve in order to get the = fuel injection to return to the tank I was using at the time. =20 It's really simple, and hopefully that means reliable. We'll have to = see, as this plane is looking for it's airworthiness inspection in the = next few months.=20 Brian Trubee __________ Information from ESET NOD32 Antivirus, version of virus = signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ------=_NextPart_000_004A_01CAC2E8.479D8FF0 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
Tracy,
 
 I do have filters between tanks and = pumps. I had=20 an issue early on with junk in the filters but never enough to = cause any=20 issue. This was just a little construction debris and remnants of some=20 automotive sealant I initially used to install the access plates (since=20 reinstalled with Proseal). I just did my first condition inspection = and=20 checked the filters about a month ago and they were clean. But I = will check=20 them again.
 
Never have had a problem previously with = pressure drop=20 across the filter. The problem happened at about the 1.3 hour point = in the flight. At the time I was motoring around at 8500' and at a = pretty=20 low power setting - EFISM said fuel flow was about 7.8 GPH. I did run it = up to=20 full power on the ground and couldn=92t duplicate.
 
My pickups have a screen and have the Vans = required=20 anti-rotation tab riveted to the access cover plate. But I suppose if I = cant=20 attribute it to anything else I should probably pull the tank and make = sure the=20 pickup hasn=92t moved. Man that sounds like a lot of work.
 
Mike  

Sent: Saturday, March 13, 2010 10:35 AM
Subject: [FlyRotary] Re: fuel supply = problem?

I had a similar thing happen but the engine would recover = when I=20 reduced throttle.  Problem was clogged filter between tank and = pump. =20 At low flow rate all was OK but pressure drop across filter at high flow = rate=20 caused pump to cavitate and fuel pressure to drop.  Did you try = high=20 throttle on ground test later?

But you didn't mention a filter = between=20 tank & pump.  That has potential problems as well since it = doesn't take=20 much trash to foul up an EFI pump & might have cleared up after it=20 passed.  Do you have only the slots in Van's suggested tank pickup = between=20 tank & pump?  Problem might have been trash going through=20 pump.

I guess Ed already mentioned the loose tank pickup problem = he=20 had.
Tracy

On Sat, Mar 13, 2010 at 11:29 AM, Mike Wills = <rv-4mike@cox.net>=20 wrote:
I'm pretty sure the turn was = coordinated. Knowing=20 that both tanks were approaching (if not below) 5 gallons, it was the = first=20 thing I thought of and I looked at the ball. It was centered. And I'm = sure=20 there is going to turn out to be about 5 gallons left in the tank so = its hard=20 to understand how this could have been an issue with the pickup = uncovering. I=20 just don=92t have a better explanation. If the pump failed I would = expect it to=20 stay failed, not work fine on the ground.
 
I didn=92t copy it, but my system I believe = is the same=20 that Ian Beadle used. I have 1 pump for each tank. The outputs are = T'eed=20 together - check valves built into the pumps prevents crossfeed. Both = tanks=20 have return lines. The return line from the fuel rail goes through an=20 industrial grade electric valve.
 
I chose this design for a couple of=20 reasons:
1) Operational simplicity. I reasoned = that most=20 fuel related problems in flight are due to stupid pilot tricks so = wanted a=20 system that was as simple to operate as possible. In its original=20 configuration all that was required to switch tanks was to flip a = single=20 toggle switch on the panel which would energize the appropriate pump = and=20 configure the return valve to return fuel to the tank it came from. = This has=20 since been modified slightly to have individual switches for each pump = so both=20 can be on at the same time if needed.
2) I had previous experience (bad) with EFI = in some=20 project cars before I built the airplane. I had a couple of fuel pump = failures=20 and in researching found strong recommendations against putting the = fuel pump=20 too far from the fuel tank. These pumps are designed to push fuel, not = draw=20 fuel. A design where both pumps have access to both tanks requires the = pumps=20 to be downstream of the fuel selector with several feet of fuel line = ahead of=20 the pump. I wanted to avoid this type of design although it apparently = is=20 working fine for Ed. My pumps are just inboard of the wing roots = literally a=20 couple of inches from the pickups in the tanks.
 
Tracy's system is mechanically simple but = has the=20 potential for pilot error resulting in pumping fuel overboard if the = transfer=20 pump is forgotten and left on. Yes, I know there are ways to address = that. And=20 clearly it works for him.
 
I think (thought?) I pretty well understand = the pros=20 and cons in my setup. All things being equal I think before = yesterday's=20 incident I would do it this way again. If it turns out that the = issue was=20 due to uncovering the pickup (not real sure how to prove that) I'd = consider=20 changing to include a header tank with a deep sump to prevent = re-occurance.=20 But I don=92t think I'd rely on suction to fill the header, think I'd = use a low=20 pressure pump like the typical Facet pump.
 
One thing is for certain. Unlike a = carbureted engine=20 which has a little cushion due to fuel in a float bowl, the instant = fuel=20 pressure drops this engine quits. It's an attention getter. = Particularly when=20 you are at the opposite corner of your test box from your home base. I = ended=20 up flying back about 70 miles hopscotching from field to = field.
 
Mike 

Sent: Saturday, March 13, 2010 1:53 AM
Subject: [FlyRotary] Re: fuel supply = problem?

There is = certainly=20 more than one way to design a reliable fuel system =96 each with its = pros and=20 cons.  I too did not want a six way value for switching fuel = between two=20 tanks and the engine with the ugh return line.  Besides I had = already=20 constructed my fuel system pretty much according to Van=92s = instructions. =20 So to preclude a return line I came up with my =93almost returnless=94 = system.  It uses a =BD pint capacity small header tank to return = the=20 injector fuel =96 the fuel injected to the engine comes from this = header tank=20 thereby creating a =93vacuum=94 in the tank which pulls fresh fuel = from the wing=20 tanks.  It has worked fine for over 10 years.

 

Both fuel = pumps draw=20 from this header tank and either tank can feed it and I have no return = lines=20 going back to the tanks.

 

But, = Tracy=92s approach=20 has shown to work just fine =96 not knocking it by any = means.

 

Ed

 

Ed=20 Anderson

Rv-6A N494BW=20 Rotary Powered

Matthews,=20 NC

eanderson@carolina.rr.com

http://www.andersonee.com

http://www.dmack.net/mazda/index.html<= /P>

http://www.flyrotary.com/

http://members.cox.net/rogersda/rotary/configs.htm#N494BW

http://www.rotaryaviation.com/Rotorhead%20Truth.htm

From: Rotary=20 motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bktrub@aol.com
Sent: Friday, March 12, 2010 = 11:43=20 PM
To: Rotary = motors in=20 aircraft
Subject: = [FlyRotary]=20 Re: fuel supply problem?

 

I just = copied=20 Tracy's setup- all fuel is pumped from the right tank, and fuel is = transferred=20 from the left into the right by a Facet pump. I didn't want to get = into having=20 a six port fuel valve in order to get the fuel injection to return to = the tank=20 I was using at the time.  

It's = really simple,=20 and hopefully that means reliable. We'll have to see, as this plane is = looking=20 for it's airworthiness inspection in the next few months.=20

 

Brian=20 Trubee



__________=20 Information from ESET NOD32 Antivirus, version of virus signature = database=20 3267 (20080714) __________

The message was checked by ESET = NOD32=20 Antivirus.

http://www.eset.com


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