Return-Path: Received: from imf23aec.mail.bellsouth.net ([205.152.59.71] verified) by logan.com (CommuniGate Pro SMTP 4.3c1) with ESMTP id 740925 for flyrotary@lancaironline.net; Tue, 15 Feb 2005 21:51:03 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.71; envelope-from=sqpilot@bellsouth.net Received: from [216.78.115.119] by imf23aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with ESMTP id <20050216025011.PLIY2276.imf23aec.mail.bellsouth.net@[216.78.115.119]> for ; Tue, 15 Feb 2005 21:50:11 -0500 Received: from 127.0.0.1 (AVG SMTP 7.0.300 [265.8.8]); Tue, 15 Feb 2005 20:50:04 -0600 Message-ID: <00f501c513d2$36d732e0$77734ed8@paul52u7f5qyav> From: "Paul" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Bad day at the airport Date: Tue, 15 Feb 2005 20:50:03 -0600 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 Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="=======AVGMAIL-4212B4DC072E=======" --=======AVGMAIL-4212B4DC072E======= Content-Type: multipart/alternative; boundary="----=_NextPart_000_00F2_01C5139F.EC1DC930" ------=_NextPart_000_00F2_01C5139F.EC1DC930 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi, Jim....yes, I use the same gasoline as I use in my car. (Regular = unleaded). I think Tracy and Ed Anderson also use it, as they mentioned = that their spark plug life is greatly deteriorated when they are forced = to use 100LL. Guys, please step in here and correct me if I am wrong.=20 Regarding alcohol, I am not overly concerned with it. I coated my = fuel tanks with 3 coats of the fuel tank sealant that comes with the = kit. (Smells like dead fish). It is supposed to be imperviant to auto = fuel and alcohol. Time will tell. Paul Conner ----- Original Message -----=20 From: Jim Sower=20 To: Rotary motors in aircraft=20 Sent: Tuesday, February 15, 2005 12:28 AM Subject: [FlyRotary] Re: Bad day at the airport <... I was using auto fuel (regular). I have a fuel return line and it = goes ...> DAMN. I hadn't heard about that. Paul, that's a really important = factor. Maybe I lost it in all the chatter going on. Auto fuel can be = pretty close to avgas in volatility (Vapor Pressure) but for the most = part it's anyone's guess. Avgas is regulated at max~ 6 psi Vapor = Pressure. Mogas used to get as high as 16-20 psi VP. That high a = pressure can petty much guarantee vapor lock under high under hood / = cowl conditions. As time went on and more and more cars got MPFI and = environmental regulations progressed, Mogas vapor pressures came down = some. IIRC Calif has a 7-8 psi max vapor pressure, and places with = strict environmental regulations (like cities who aren't making their = air quality numbers) are more likely to require lower VPs. Trouble is, = VP can vary widely across various sources of Mogas. I would guess that anywhere that requires gas pump nozzles that = capture vapor as you fill your tank will have lower VPs, but sadly, they = are also most likely to have alcohol added to mogas. Alcohol is a major = NO NO for aircraft. Mogas fuel systems should be very carefully = designed to prevent vapor lock or you are apt to get into some VERY = SERIOUS SHIT!!. Like there have been maybe 80,000 Mogas STCs issued to = Lycs and Conts. NONE to ANY certified engine that's injected. Which is not to say that you can't make a system that runs reliably = with higher VP Mogas, but you need to be very VERY attentive to the = issue, both in design and operation. You also have to figure out a way = to find out what local VPs are. Alcohol is easy to detect and = distributors know how much they're adding to the fuel. Good info on VP = is more difficult to come by and it might vary some from one distributor = to another. I've been researching Mogas and recently gave a little presentation to = my EAA chapter and a couple of flying clubs. It's wonderful stuff for = your engine (lead is really terrible) but you need to be very careful to = not allow ANY alcohol into your airplane and be very careful about = checking and monitoring VP. Unleaded Avgas is coming, but VP will be an issue with it ... Jim S. Mark R Steitle wrote:=20 Paul, It looks like the group has focused in on the fuel system, or more = specifically the sump tank as the likely culprit. I suspected you might = have been running mogas. Its my understanding that auto fuel has a much = lower vapor pressure than avgas and is therefore more likely to vapor = lock. =20 Just a SWAG, but I think the engine and related systems got hot = enough to heat the fuel in the fuel rails so that once it passed the = pressure regulator (pressure drop) it started to boil, similar to when = you open a hot soda. With the return fuel going to an unvented tank, = the boiling fuel expanded enough to cause pressure in the header tank so = as to prevent fresh fuel from flowing into the tank. Eventually, the = header tank ran dry and the engine quit. You sure handled the situation = like a pro. Hope I never have to face that scenario. Mark S.=20 =20 Hi, Mark...my humblest appologies for taking so long to respond. I = am whittling down the 200 plus messages in my inbox. I was using auto = fuel (regular). I have a fuel return line and it goes to the top of my = aluminum sump tank that is located on the cool side of the firewall = (inside the cabin, behind the rear seat). The return line is -8 in size. = Hope this helps. Paul Conner -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.300 / Virus Database: 265.8.7 - Release Date: 2/10/2005 ------=_NextPart_000_00F2_01C5139F.EC1DC930 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi, Jim....yes, I use the same gasoline = as I use in=20 my car. (Regular unleaded).  I think Tracy and Ed Anderson also use = it, as=20 they mentioned that their spark plug life is greatly deteriorated when = they are=20 forced to use 100LL.  Guys, please step in here and correct me if I = am=20 wrong.
      = Regarding alcohol, I=20 am not overly concerned with it. I coated my fuel tanks with 3 coats of = the fuel=20 tank sealant that comes with the kit. (Smells like dead fish). It is = supposed to=20 be imperviant to auto fuel and alcohol.  Time will tell.  Paul = Conner
 
----- Original Message -----
From:=20 Jim=20 Sower
Sent: Tuesday, February 15, = 2005 12:28=20 AM
Subject: [FlyRotary] Re: Bad = day at the=20 airport

<... I was using auto = fuel=20 (regular). I have a fuel return line and it goes = ...>

DAMN.  I=20 hadn't heard about that.  Paul, that's a really important = factor. =20 Maybe I lost it in all the chatter going on.  Auto fuel = can be=20 pretty close to avgas in volatility (Vapor Pressure) but for the most = part=20 it's anyone's guess.  Avgas is regulated at max~ 6 psi Vapor=20 Pressure.  Mogas used to get as high as 16-20 psi = VP.  That=20 high a pressure can petty much guarantee vapor lock under high under = hood /=20 cowl conditions.  As time went on and more and more cars got MPFI = and=20 environmental regulations progressed, Mogas vapor pressures came down=20 some.  IIRC Calif has a 7-8 psi max vapor pressure, and places = with=20 strict environmental regulations (like cities who aren't making their = air=20 quality numbers) are more likely to require lower VPs.  Trouble = is, VP=20 can vary widely across various sources of Mogas.

I would guess = that=20 anywhere that requires gas pump nozzles that capture vapor as you fill = your=20 tank will have lower VPs, but sadly, they are also most likely to have = alcohol=20 added to mogas.  Alcohol is a major NO NO for aircraft.  = Mogas fuel=20 systems should be very carefully designed to prevent vapor lock or you = are apt=20 to get into some VERY SERIOUS SHIT!!.  Like there have been maybe = 80,000=20 Mogas STCs  issued to Lycs and Conts.  NONE to ANY certified = engine=20 that's injected.

Which is not to say that you can't make a = system that=20 runs reliably with higher VP Mogas, but you need to be very VERY = attentive to=20 the issue, both in design and operation.  You also have to figure = out a=20 way to find out what local VPs are.  Alcohol is easy to detect = and=20 distributors know how much they're adding to the fuel.  Good info = on VP=20 is more difficult to come by and it might vary some from one = distributor to=20 another.

I've been researching Mogas and recently gave a little = presentation to my EAA chapter and a couple of flying clubs.  = It's=20 wonderful stuff for your engine (lead is really terrible) but you need = to be=20 very careful to not allow ANY alcohol into your airplane and be very = careful=20 about checking and monitoring VP.

Unleaded Avgas is coming, but = VP will=20 be an issue with it ... Jim S.


Mark R Steitle = wrote:=20

Paul,

It looks = like the=20 group has focused in on the fuel system, or more specifically the = sump tank=20 as the likely culprit.  I suspected you might have been running = mogas.=20  Its my understanding that auto fuel has a much lower vapor = pressure=20 than avgas and is therefore more likely to vapor lock. =20

Just a = SWAG, but I=20 think the engine and related systems got hot enough to heat the fuel = in the=20 fuel rails so that once it passed the pressure regulator (pressure = drop) it=20 started to boil, similar to when you open a hot soda.  With the = return=20 fuel going to an unvented tank, the boiling fuel expanded enough to = cause=20 pressure in the header tank so as to prevent fresh fuel from flowing = into=20 the tank.  Eventually, the header tank ran dry and the engine=20 quit.  You sure handled the situation like a pro.  Hope I = never=20 have to face that scenario.

Mark S.=20

 =20

Hi, Mark...my humblest = appologies for taking so long to respond.  I am whittling down = the 200=20 plus messages in my inbox.  I was using auto fuel (regular). I = have a=20 fuel return line and it goes to the top of my aluminum sump tank = that is=20 located on the cool side of the firewall (inside the cabin, behind = the rear=20 seat). The return line is -8 in size.  Hope this helps.  = Paul=20 Conner

No virus found in this incoming message.
Checked by AVG=20 Anti-Virus.
Version: 7.0.300 / Virus Database: 265.8.7 - Release = Date:=20 2/10/2005
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