X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao102.cox.net ([68.230.241.44] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTP id 3519387 for flyrotary@lancaironline.net; Fri, 27 Feb 2009 11:34:40 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.44; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao102.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090227163406.MLHJ13097.fed1rmmtao102.cox.net@fed1rmimpo02.cox.net> for ; Fri, 27 Feb 2009 11:34:06 -0500 Received: from wills ([68.105.85.56]) by fed1rmimpo02.cox.net with bizsmtp id M4a31b00B1CvZmk044a5zA; Fri, 27 Feb 2009 11:34:05 -0500 X-Authority-Analysis: v=1.0 c=1 a=kviXuzpPAAAA:8 a=FRaAOfBRHqhhC9MOwosA:9 a=FHmO5AExrXH_JqfA9tEA:7 a=VctKBootHR5lXqv8vhN-7WtKGuUA:4 a=zoKOyUDlhksA:10 a=4vB-4DCPJfMA:10 a=UretUmmEAAAA:8 a=Ia-xEzejAAAA:8 a=mvbMTDOfxdGeeEi5Kc4A:9 a=PZBBebnLoymiLyxWlK0A:7 a=39d6OueE5rsOJK_NrUDURpW2z3gA:4 a=AfD3MYMu9mQA:10 a=iVkDmfvjeKcA:10 a=EzXvWhQp4_cA:10 X-CM-Score: 0.00 Message-ID: <001d01c998f9$7cc8e8b0$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: ethanol Date: Fri, 27 Feb 2009 08:36:05 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001A_01C998B6.6E595D70" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 This is a multi-part message in MIME format. ------=_NextPart_000_001A_01C998B6.6E595D70 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Before my airplane hobby I was a hot-rodder and one of the early = adopters of EFI on a Chevy powered Datsun Z. I learned the hard way that = EFI pumps dont like to draw fuel over great distances. On the RV-4 the = pumps are just inside the fuselage at the wingroot. The only possible = way to make the path shorter would be to put them between the wing and = fuselage and I looked at doing that but couldnt make the plumbing work. = When I switch on the pump, I see fuel pressure instantly on the gauge. I = can hear the pump prime and pick up fuel - its a fraction of a second. I use filters between the tank and pumps that have a sintered bronze = element. They are rated @ 300 GPH and can be disassembled for cleaning. = The first time I found contamination each filter contained about 1/8 tsp = of junk in it. Thanks for the idea about the hose possibly being affected and returned = to the tank Mark. Earls isnt real specific about what the hose is made = of. May be time to do some testing. Al, I dont routinely test but every sample I have tested from various = gas stations around the county has had ethanol in it. I found a number = of websites that indicated there is NO MTBE in CA gas anymore and that = all gas sold here contains a minimum of approx 6% ethanol as an = oxygenate. Mike ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Friday, February 27, 2009 7:43 AM Subject: [FlyRotary] Re: ethanol FWIW, Possible source of the 'black flakes' is fuel pump impeller pieces. = When these pumps run dry their lifetime is measured in minutes. The = impellers will abraid and shed small pieces. Insure that the path from = tank to pump is down hill or at least level with the fuel and there are = no restrictive filters or other obstacles in this path. I don't even = like to see boost pumps there because there is a significant drop in = pressure across their check valves. Tracy On Thu, Feb 26, 2009 at 10:59 PM, Mike Wills wrote: Well things seem a little slow today so how about re-opening a can = of worms? We had a brief discussion a while back regarding ethanol in = fuel. Frankly at the time I didnt know much about the subject but have = been reading a little since I'm burning auto fuel. At the time I think it was Al G. who said so far he hasnt found any = auto fuel with ethanol in it. If I got that wrong I apologize. So far I = havent found any auto fuel that DOESNT. As far as I can tell from my = reading ALL auto fuel in CA has at least 6% and most is at 10% now. Looks like the concerns are: 1) Vapor lock 2) Potential corrosion of aluminum components in the fuel system. 3) Deterioration of rubber (and other?) components in the fuel = system. 4) Water. 5) Dislodging contaminants from previously used fuels. I believe (hope?) the vapor lock issues to be a non-problem with our = EFI systems. The potential corrosion issues seem to be overstated for = ethanol, clearly a problem with methanol. All the hose in my airplane is = Earls Perform-O-Flex which according to their website is "synthetic = rubber". I assume they mean neoprene which I gather is ethanol safe. I = assume the injectors themselves are safe? I thought Pro-Seal is also = supposed to be ethanol safe. My airplane is new so there should be no = issue with dislodged contaminants. This leaves the issue of ethanol's affinity for water. Other than = always keeping the tanks full to minimize airspace in the tank and = condensation any ideas on how to deal with this other than hoping it = doesnt happen? I bring this subject up because for the second time since I've = started flying I've found a little contamination during my pre-flight = when sumping the tanks. Each fuel sample has a few ground pepper sized = black flakes in it. Whatever it is it crumbles to powder between the = fingers. The first time I completely drained the tanks and pulled the = fuel filters and cleaned them. When I refilled the tanks I used a Mr. = Funnel to make sure nothing bad got added. So whatever this is, its = residual junk in the tanks from when they were built. Or its something = (like ethanol) attacking the Pro Seal. Any comments on ethanol in general or my fuel contamination issue = are welcome. Mike Wills RV-4 N144MW ------=_NextPart_000_001A_01C998B6.6E595D70 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Before my airplane hobby I was a = hot-rodder and one=20 of the early adopters of EFI on a Chevy powered Datsun Z. I learned the = hard way=20 that EFI pumps dont like to draw fuel over great distances. On the RV-4 = the=20 pumps are just inside the fuselage at the wingroot. The only = possible way=20 to make the path shorter would be to put them between the wing and = fuselage and=20 I looked at doing that but couldnt make the plumbing work. When I switch = on the=20 pump, I see fuel pressure instantly on the gauge. I can hear the pump = prime and=20 pick up fuel - its a fraction of a second.
 
I use filters between the tank and = pumps that have=20 a sintered bronze element. They are rated @ 300 GPH and can be = disassembled for=20 cleaning. The first time I found contamination each filter contained = about 1/8=20 tsp of junk in it.
 
Thanks for the idea about the hose = possibly being=20 affected and returned to the tank Mark. Earls isnt real specific about = what the=20 hose is made of. May be time to do some testing.
 
Al, I dont routinely test but every = sample I have=20 tested from various gas stations around the county has had ethanol in = it. I=20 found a number of websites that indicated there is NO MTBE in CA gas = anymore and=20 that all gas sold here contains a minimum of approx 6% ethanol as an=20 oxygenate.
 
Mike
----- Original Message -----
From:=20 Tracy=20 Crook
Sent: Friday, February 27, 2009 = 7:43=20 AM
Subject: [FlyRotary] Re: = ethanol

FWIW,
Possible source of the 'black flakes'  is = fuel=20 pump impeller pieces.  When these pumps run dry their lifetime is = measured in minutes.  The impellers will abraid and shed small=20 pieces.  Insure that the path from tank to pump is down hill or = at least=20 level with the fuel and there are no restrictive filters or other = obstacles in=20 this path.  I don't even like to see boost pumps there because = there is a=20 significant drop in pressure across their check=20 valves.

Tracy


On Thu, Feb 26, 2009 at 10:59 PM, Mike Wills = <rv-4mike@cox.net>=20 wrote:
Well things seem a little slow = today so how=20 about re-opening a can of worms? We had a brief discussion a while = back=20 regarding ethanol in fuel. Frankly at the time I didnt know much = about the=20 subject but have been reading a little since I'm burning auto=20 fuel.
 
At the time I think it was Al G. = who said so=20 far he hasnt found any auto fuel with ethanol in it. If I got that = wrong I=20 apologize. So far I havent found any auto fuel that DOESNT. As far = as I can=20 tell from my reading ALL auto fuel in CA has at least 6% and most is = at 10%=20 now.
 
Looks like the concerns = are:
1) Vapor lock
2) Potential corrosion of aluminum = components=20 in the fuel system.
3) Deterioration of rubber (and = other?)=20 components in the fuel system.
4) Water.
5) Dislodging contaminants from = previously used=20 fuels.
 
I believe (hope?) the vapor = lock issues to=20 be a non-problem with our EFI systems. The potential corrosion=20 issues seem to be overstated for ethanol, clearly a problem = with=20 methanol. All the hose in my airplane is Earls Perform-O-Flex which=20 according to their website is "synthetic rubber". I assume they mean = neoprene which I gather is ethanol safe. I assume the injectors = themselves=20 are safe? I thought Pro-Seal is also supposed to be = ethanol safe.=20 My airplane is new so there should be no issue with dislodged=20 contaminants.
 
This leaves the issue of ethanol's = affinity for=20 water. Other than always keeping the tanks full to minimize airspace = in the=20 tank and condensation any ideas on how to deal with this other than = hoping=20 it doesnt happen?
 
I bring this subject up because for = the second=20 time since I've started flying I've found a little contamination = during my=20 pre-flight when sumping the tanks. Each fuel sample has a few ground = pepper=20 sized black flakes in it. Whatever it is it crumbles to powder = between the=20 fingers. The first time I completely drained the tanks and = pulled the=20 fuel filters and cleaned them. When I refilled the tanks I used a = Mr. Funnel=20 to make sure nothing bad got added. So whatever this is, its = residual junk=20 in the tanks from when they were built. Or its something (like = ethanol)=20 attacking the Pro Seal.
 
Any comments on ethanol in general = or my fuel=20 contamination issue are welcome.
 
Mike Wills
RV-4=20 = N144MW

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