X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-gx0-f16.google.com ([209.85.217.16] verified) by logan.com (CommuniGate Pro SMTP 5.2.9) with ESMTP id 3232223 for flyrotary@lancaironline.net; Tue, 21 Oct 2008 09:05:05 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.217.16; envelope-from=wdleonard@gmail.com Received: by gxk9 with SMTP id 9so5067293gxk.19 for ; Tue, 21 Oct 2008 06:04:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:in-reply-to:mime-version:content-type:references; bh=TsmyN8SWzqMMTnMv86wyj1bIq63byXvkvSIJHazSnZo=; b=FLp2LO9Owxv6VJ5lpmxSIN4L+24MkB/yNOMA7GWfgDpaOYaG+frhG16dFPt6H/uN6O Ua1B6ncEUXU3S9tDBpziMk/SwwGAo+pCHbGEYJEInYdgSHXDltwD8BQrU/55TjQv2h5b S+5DG3tS6808rtkqL/dAFhSwdVVOGNz1xGn48= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version :content-type:references; b=dIRB2dTF44iDAKuWVuG05hMpipwmJLhwZepEoB+OA4E8saJUi9oUIZ6960YfrO9dPs Aq9sDugtCqpA0dlRgRHAcR3aHy41qsRbC/84u2jrPj9upxutp/sF0Brw0rhUipLXhJpg 3Oa9c9tS1SNe/xmSTWaoz7nhBnE4l6IvP7o2k= Received: by 10.150.228.12 with SMTP id a12mr1642745ybh.248.1224594268465; Tue, 21 Oct 2008 06:04:28 -0700 (PDT) Received: by 10.150.206.12 with HTTP; Tue, 21 Oct 2008 06:04:28 -0700 (PDT) Message-ID: <1c23473f0810210604k243b9bedl7791f411a234846f@mail.gmail.com> Date: Tue, 21 Oct 2008 06:04:28 -0700 From: "David Leonard" To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Water in the fuel? In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_3087_10431890.1224594268422" References: ------=_Part_3087_10431890.1224594268422 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hi Ed, When traveling cross country, I will often get a few seconds of stumble after switching to the second tank if I have not been careful to mix the 2-stroke oil well. At home it mixes in the gerry cans but on the road it has to mix in the tank. The problem is particularly bad if I am fillling the tank from empty because then there is a 19oz boulus of oil that is difficult to mix. The best way is to half fill the tank, pour in the oil and shake shake shake, then finish fueling. But often it dosent work that way (like when I have to run off to pee and someone else fills the tanks etc...) Tanks that are already partially filled are not nearly as much problem because the oil mixes better when there is already some gas there - and the amount of oil is smaller. Since you usually use 100LL you have probably worked out these issues and could give me advise on how to mix the oil while on the road. --=20 David Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Mon, Oct 20, 2008 at 12:16 PM, Ed Anderson wr= ote: > Good point, Lynn. If I had a bit better presence of mind, I would have > checked the air/Fuel ratio indicator to see if it went lean when the engi= ne > stumbled. But, alas, I simply can't seem to remain sufficiently detache= d > from the situation at hand when the engine is dying - to study secondary > effects{:>) > > > > Ed > > > > Ed Anderson > > Rv-6A N494BW Rotary Powered > > Matthews, NC > > eanderson@carolina.rr.com > > http://www.andersonee.com > > http://members.cox.net/rogersda/rotary/configs.htm#N494BW > > http://www.dmack.net/mazda/index.html > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Lynn Hanover > *Sent:* Monday, October 20, 2008 11:17 AM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Water in the fuel? > > > > I always like to share happy little "incidents" with others on the list i= n > hopes we all might benefit =96 not just me {:>). I landed at Shady Bend > none-stop from NC with the left tank empty and 14.7 gallons in the right > tank. > > > > On the way returning from the Rotary Round up at Shady bend; I stopped to > refuel at WayCross, GA as I normally do. Everything thing has been work > outstandingly on the trip thus far. > > > > I took off and got up to my intended cruise of 5500 MSL (30 kt headwind > there, but bumpy as heck any lower). With such a headwind, I knew the > flight would be uneventful (the incidents happen when I have a tail wind)= . > After about 30 minutes I decided to switch from my right wing tank to my > left. So I turned on the boost pump and both high pressure pumps and tur= ned > the fuel selector switch to the left tank. > > > > Normally there is a non-event, there is no hiccup or hesitation =96 > normally! Well this time things were different, the engine started to > surge - big time =96 as did my heart. The fuel pressure is wiggling a s= mall > amount but clearly with pressure above 35 psi it is adequate. > > > > My mind races back to that incident a long time ago where I glided 12 > miles engine out =96 and I decided there was no benefit to be gained by > repeating that experience. So as I rapidly raced cause and solution > hypothesis through my head, I reached over and turned on the cold start > switch. The engine began to run almost normally, I switched cold start o= ff > and the surge returned. I hit "nearest" on my Garmin and turned toward t= he > nearest airport (17 miles). Then back to the engine. It is still surgin= g > although not quite as badly as it had been =96 but still way too much to = be > comfortable with =96 and that fuel pressure is still nominally around 40 = psi. > What goes? > > > > I then turned off my secondary injectors - the engine began to run smooth= ly > (although I don't know if this was more than a coincident of timing). S= o > recalling my lesson learned from that earlier incident (switch tanks, > dummy!), I switched back to the right tank =96 happily every thing settle= d > down (including my heart) and the engine ran normally. > > > > After getting a bit closer to the target airport, I gathered my nerves > (what remained of them) and switched back to the left tank =96 there was = a > momentary burble, but then the engine started running normally and did so > for the rest of the flight burning 10 gallons out of that tank. > > > > Naturally, I am trying to figure out what could possibility have cause th= is > momentary hiccup. Here is the best I can come up with. > > > > I landed at Shady bend with the left tank with approx =BE gallon in it. = It > so happens the gas cap on that tank is in need of an O ring replacement a= s I > noticed a small amount of fuel streaming from the cap area. Well, the > aircraft set outside through a few light rain showers while at Shady Bend= . > I believe that water may have seeped through the cap and collected in the > tank. (No, I did not do a drain of my tanks checking for water as I shou= ld > have). I used to do it religiously, but after 8 years of so of never > finding a single drop of water, I had lapsed in that check. No excuses = =96 > just the facts. > > > > So if a =BD cup or water or so had gotten into that empty tank, it would > naturally have settled at the bottom =96 right next to the fuel pick up. = I > refueled at WayCross putting fuel into both tanks =96 no problem with the > right tank (with a non-leaking cap). So I believe that I took off with s= ome > amount of water in the left tank. When I switched fuel tanks that slug o= f > water was sitting right there waiting to be sucked into the system. This= is > why (I believe) the fuel pressure did not go down as it would have if the= re > had been no liquid being pumped through the system. So it basically too= k a > few hair raising moments to suck all the water through the system and int= o > the engine =96 then all was well. > > > > I am not certain why hitting the "cold Start" switch would have made any > difference, but I did turn it on twice and each time the engine settled > down. Also when the secondary injectors were momentarily turned off the > engine smoothed out. It may have to do with injecting water into the > secondaries (which are positioned further away from the engine) and perha= ps > the evaporative effect was sufficient to freeze the water vapor??? Don't > know, but I am convinced that water in the fuel was the most likely cause= . > > > > I think the principal point is that had I done the fuel drain according t= o > Hoyle I would have likely discovered the water and drained it. So once > again, a bit red-faced to admit to failing to follow long established > check-list procedures (I know none of the rest of you do that), I found a= n > interesting "incident" to relate to the list. > > > > Fly Safely out there =96 Ya' hear! > > > > > > Ed > > *It is so nice of you to investigate every known failure mode, so the res= t > of us lessor pilots don't have to. *Thank you............ > > > > *The water injected, is displacing a like volume of fuel. It is not > actually the water that causes the stumble, but the fact that the engine = is > starved for fuel (over lean mixture). So the cold start adds fuel and the > engine runs again. * > > > > *Lynn E. Hanover* > > > > Ed Anderson > > Rv-6A N494BW Rotary Powered > > Matthews, NC > > eanderson@carolina.rr.com > ------=_Part_3087_10431890.1224594268422 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hi Ed,

When traveling cross country, I will often get a few seconds = of stumble after switching to the second tank if I have not been careful to= mix the 2-stroke oil well.  At home it mixes in the gerry cans but on= the road it has to mix in the tank.  The problem is particularly bad = if I am fillling the tank from empty because then there is a 19oz boulus of= oil that is difficult to mix.  The best way is to half fill the tank,= pour in the oil and shake shake shake, then finish fueling.  But ofte= n it dosent work that way (like when I have to run off to pee and someone e= lse fills the tanks etc...)

Tanks that are already partially filled are not nearly as much problem = because the oil mixes better when there is already some gas there - and the= amount of oil is smaller.

Since you usually use 100LL you have prob= ably worked out these issues and could give me advise on how to mix the oil= while on the road.

--
David Leonard

Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net

On Mon, Oct 20, 2008 at 12:16 PM, Ed Anderson <eanderson@carolina.rr.com> wrote:

Good point, Lynn.  If I had a= bit better presence of mind, I would have checked the air/Fuel ratio indicator to see if it went l= ean when the engine stumbled.  But, alas, I simply can't  seem to rem= ain sufficiently detached from the situation at hand when the engine is dying -= to study secondary effects{:>)

 

Ed

 

From: Ro= tary motors in aircraft [mailto:fl= yrotary@lancaironline.net] On Behalf Of Lynn Hanover
Sent: Monday, October 20, = 2008 11:17 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Water= in the fuel?

 

I always like to share happy little "incidents" with others on the list in hopes we all might benefit =96 not just me {:>).  I landed at Shady= Bend none-stop from NC with the left tank empty and 14.7 gallons in the right tank. 

 

On the way returning from the Rotary Round up at Shady bend; I stopped to refuel at Wa= yCross, GA as I normally do.  Everything thing has been work outstandingly on the trip thus far.

 

I took off and got up to my intended cruise of 5500 MSL (30 kt headwind there, but bum= py as heck any lower).  With such a headwind, I knew the flight would be uneventful (the incidents happen when I have a tail wind).    After about 30 minutes I decided to switch from my right wing tank to= my left.  So I turned on the boost pump and both high pressure pumps and turned the fuel selector switch to the left tank.

 

Normally there is a non-event, there is no hiccup or hesitation =96 normally! &= nbsp; Well this time things were different, the engine started to  surge - b= ig time =96 as did my heart.  The fuel pressure is wiggling a small amoun= t but clearly with pressure above 35 psi it is adequate.

 

 My mind races back to that incident a long time ago where I glided 12 miles en= gine out =96 and I decided there was no benefit to be gained by repeating that experience.  So as I rapidly raced cause and solution hypothesis throu= gh my head, I reached over and turned on the cold start switch.  The engi= ne began to run almost normally, I switched cold start off and the surge returned.  I hit "nearest" on my Garmin and turned toward th= e nearest airport (17 miles).  Then back to the engine.  It is stil= l surging although not quite as badly as it had been =96 but still way too mu= ch to be comfortable with =96 and that fuel pressure is still nominally around 40 psi.  What goes? 

 

I then turned off my secondary injectors - the engine began to run smoothly (altho= ugh I don't know if  this was more than a coincident of timing). = So recalling my lesson learned from that earlier incident (switch tanks, dummy= !), I switched back to the right tank =96 happily every thing settled down (inc= luding my heart) and the engine ran normally.

 

After getting a bit closer to the target airport, I gathered my nerves (what rema= ined of them) and switched back to the left tank =96 there was a momentary burbl= e, but then the engine started running normally and did so for the rest of the fli= ght burning 10 gallons out of that tank.

 

Naturally, I am trying to figure out what could possibility have cause this momentary hiccup.  Here is the best I can come up with.

 

I landed at Shady bend with the left tank with approx =BE gallon in it.  It so hap= pens the gas cap on that tank is in need of an O ring replacement as I noticed a small amount of fuel streaming from the cap area.  Well, the aircraft = set outside through a few light rain showers while at Shady Bend.  I belie= ve that water may have seeped through the cap and collected in the tank.  (No, I did not do a drain of my tanks checking for water as I should have).  I used to do it religiously, but after 8 years of so of never finding a single drop of water, I had lapsed in that check.  No excuse= s =96 just the facts.

 

So if a =BD cup or water or so had gotten into that empty tank, it would naturally have settled at the bottom =96 right next to the fuel pick up.  I refueled = at WayCross putting fuel into both tanks =96 no problem with the right tank (with a non-leaking cap).  So I believe that I took off with some amount of water in the l= eft tank.  When I switched fuel tanks that slug of water was sitting right there waiting to be sucked into the system.  This is why (I believe) t= he fuel pressure did not go down as it would have if there had been no liquid being pumped through the system.   So it basically took a few hai= r raising moments to suck all the water through the system and into the engin= e =96 then all was well.

 

I am not certain why hitting the "cold Start" switch would have made any difference, but I did turn it on twice and each time the engine settled down.  Also when the secondary injectors were momentarily turned off t= he engine smoothed out.  It may have to do with injecting water into the secondaries (which are positioned further away from the engine) and perhaps= the evaporative effect was sufficient to freeze the water vapor???  Don= 9;t know, but I am convinced that water in the fuel was the most likely cause.<= /span>

 

I think the principal point is that had I done the fuel drain according to Hoyle I woul= d have likely discovered the water and drained it.  So once again, a bit red-faced to admit to failing to follow long established check-list procedu= res (I know none of the rest of you do that), I found an interesting "inci= dent" to relate to the list.

 

Fly Safely out there =96 Ya' hear!

 

 

Ed

It is so nice of you to investigate every known failure mode, so the rest of us lessor pilots don't have to. Thank you............

 

The water injected, is displacing a like volume of fuel. It is not actually the water that causes the stumble, but the fact th= at the engine is starved for fuel (over lean mixture). So the cold start adds = fuel and the engine runs again. 

 

Lynn E. Hanover

 

Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews, NC

eanderson@carolina.rr.com




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