X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-px0-f185.google.com ([209.85.216.185] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3866593 for flyrotary@lancaironline.net; Sat, 26 Sep 2009 12:23:52 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.216.185; envelope-from=wdleonard@gmail.com Received: by pxi15 with SMTP id 15so3970455pxi.25 for ; Sat, 26 Sep 2009 09:23:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type; bh=y77gc+Fd0x3omfEzbOtjiGkFicHh2/3o0DaNGg1TOe4=; b=p2iEHwoXR4hiDw64uu7AAXeKLt6ePLCjhLZAZBHYuOQ8Ej7hTdKryU34Boje0ozu8K gr+xrp+xQRxRClo1aKsZKENhkp+VniOqM4FU3iJYSwTpnoeG3i/qUrEXgAGrDnEU7I1w csILn5UdDkF/rig36a8HNNcIrbLOzVz1rLY9k= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=FvpsHxOiBZ0z6OKj8TQbUakAzRbi6ZWMKxEnKK1g5ts8DUqQoXuQqEJ9TmtXeigrBb xnDFLodvtEjwKZe0RgbFOGCjO3JXCXwIoGGrJPdN8uN8TTNzAycu3VRGYkcG5Nf8PlUT awmxrpf2VgeSsNr62W33V+fO7gRDPCvnrKpTs= MIME-Version: 1.0 Received: by 10.142.1.41 with SMTP id 41mr106828wfa.108.1253982198248; Sat, 26 Sep 2009 09:23:18 -0700 (PDT) In-Reply-To: References: Date: Sat, 26 Sep 2009 09:23:18 -0700 Message-ID: <1c23473f0909260923h1b4e6c17w3cd178b62d94a617@mail.gmail.com> Subject: Re: [FlyRotary] gas smell From: David Leonard To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=00504502bb377b35db04747d7bc0 --00504502bb377b35db04747d7bc0 Content-Type: text/plain; charset=ISO-8859-1 Mike, I have long had a fuel smell in the cockpit and have traced down several culprits. Each one made improvements, I have finally solved most of the issues. I know these will not all apply to you, but I am sure some will. I'll put them in chronological order here, but the ones in bold most likely apply to you. Luckily, the 2-stroke oil we put in the gas leaves a telltale residue after it builds up long enough - makes tracing these leaks much easier. And get in there with that sniffer... -Small leak at AN-flare from left tank to fuel selector. fixed by re-securing -Small leak at at fitting just downstream of fuel pump. -small leak at fuel pressure sensor NPT fitting. *-While running normally aspirated* I was getting a strong smell in flight. Tracked that down to mostly the pax fresh air inlet. This eventually traced to the intake system. Seems that even in full bore flight, *fuel from the secondary injectors (8" from inlets) would come backwards and mix with cowl air*, some of which would seep out the cowl seam, which was right ahead of the pax fresh air inlet and blowing right into Anne's face. She kept smelling really strong gas "making her sick." To me it was not quite that strong and I thought she was over reacting until I leaned over and smelled the pax air inlet - sure wish I solved that issue before flying Anne to Vegas. Solved this by re-installing some of the turbo intake piping to catch any back migrating fuel. - Very faint smell but quickly accumulating residue (oil would pool in the recesses on top of the engine) from fuel leaking out through a welding defect in the intake runners - fixed with JB Weld. It still also gets out around the axle in the throttle body while running higher than ambient MAP. I don't know how to fix that one. -There is a *small leak in the fuel vent tubing system* that runs through the cockpit, but I have not been able to find the exact location so I will still smell it a little if I start to vent fuel on a hot day. -This year my port *side fuel tank gasket* (the cork one) started leaking quite a bit *around the screws that hold the plate in pl*ace. This required removal of the entire fuel tank to get proper access because I had previously tried unsuccessfully to seal around those screws with some sort of epoxy putty. When you think about it, there is no gasket to keep fuel out around those screws. The fuel can get past the threads of the nut plate, bypass the gasket altogether, and get out around the head of the screw. 75% of those screws had 2-stroke residue. Fuel vapor from that wing root area easily gets into the cockpit in flight through the openings for the aileron pushrods and control column. I fixed that one by replacing the cork and putting some proseal under the head of each of the screws - though I wish I had used RTV. That proseal will be a real beotch if I ever need to get that plate off again. -I also found a number of very small leaks (residue) past a number of the rivets on the quick build fuel tanks. In particular, the *blind rivets on the back side just ahead of the spar* were prone to leak (about 6 of those had some amount of 2-stroke residue). I put dabs of proseal around each offender. I don't know if that fixed it (would need to remove fuel tank again to check) but the leaks were small enough to not really be a problem. - On one cross country flight I nearly gassed myself with a *dirty rag*. Some pump operator had spilled massive amounts of fuel over each wing. Actually that happens almost universally whenever I let anyone else "top it off" as those RV tanks go much faster when near full. Now I always either do it myself or specify the number of gallons to put in each tank. Anyway, there were no rags at the pump so I used one of my own and without thinking I tossed it in back. Passing through 10,000 ft the smell was so strong I was about to puke before I finally was able to reach the rag and seal it in the ice chest. Smaller amounts of spilled gas on a rag make less obvious sources of faint fuel odor. - I bought a nifty little go-ped scooter that fits in the back of the -6 and is fun to use around airports and for small trips. But on my last cross country I thought I had developed some new (and strong) fuel leak until I realized that the tank on the go-ped was probably venting as I went higher. Hope that helps :-) -- David (mostly now free of fuel smell) Leonard Turbo Rotary RV-6 N4VY http://N4VY.RotaryRoster.net http://RotaryRoster.net On Fri, Sep 25, 2009 at 7:48 PM, Mike Wills wrote: > This is one of those frustrating little issues. In ground running I dont > notice it, but in flight I smell gasoline in the cockpit. I've run it on the > ground trying to detect leaks and cant find any at all. Anyone got a > suggestion for some sort of a sniffer or telltale I could put at all the > connections that would show evidence of leaking? > > Mike Wills > RV-4 N144MW > --00504502bb377b35db04747d7bc0 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Mike,
I have long=A0had a fuel smell in the cockpit and have traced down sev= eral culprits.=A0 Each one made improvements, I have finally solved most of= the issues.=A0 I know these will not all apply to you, but I am sure some = will.=A0 I'll put them in chronological order here, but the ones in bol= d most likely apply to you.=A0 Luckily, the 2-stroke oil we put in the gas = leaves a telltale residue after it builds up long enough - makes tracing th= ese leaks much easier.=A0 And get in there with that sniffer...
=A0
-Small leak at AN-flare from left tank to fuel selector.=A0 fixed by r= e-securing
-Small leak at at fitting just downstream of fuel=A0pump.
-small leak at fuel=A0pressure sensor NPT fitting.
-While running normally aspirated I was getting a str= ong smell in flight.=A0 Tracked that down to mostly the pax fresh air inlet= .=A0
This eventually traced to the=A0intake system.=A0 Seems that even in f= ull=A0bore flight, fuel from the secondary injectors (8" from = inlets)=A0would come backwards and mix with cowl air, some of whic= h would seep out the cowl seam, which was right ahead of the pax fresh air = inlet and blowing right into Anne's face.=A0 She kept smelling really s= trong gas "making her sick."=A0 To me it was not quite that stron= g and I thought she was over reacting until I leaned over and smelled the p= ax air inlet - sure wish I solved that issue before flying Anne to Vegas.= =A0 Solved this by re-installing some of the turbo intake piping to catch a= ny back migrating fuel.
- Very faint smell but quickly accumulating residue (oil would pool in= the recesses=A0on top of the engine)=A0from fuel leaking out through a wel= ding defect in the intake runners - fixed with JB Weld.=A0 It still also ge= ts out around the axle in the throttle body while=A0running higher than amb= ient MAP.=A0 I don't know how to fix that one.
-There is a small leak in the fuel vent tubing=A0system=A0that runs through the cockpit, but I have not been able to find the ex= act location so I will still smell it a little if I start to vent fuel on a= hot day.
-This year my port side fuel tank gasket (the cork on= e) started leaking quite a bit around the screws that hold the plat= e in place.=A0 This required removal of the entire fuel tank to ge= t proper access because I had previously tried unsuccessfully to seal aroun= d those screws with some sort of epoxy putty.=A0 When you think about it, t= here is no gasket to keep fuel out around those screws.=A0 The fuel can get= past the threads of the nut plate, bypass the gasket altogether, and get o= ut around the head of the screw.=A0 75% of those screws had 2-stroke residu= e.=A0 Fuel vapor from that wing root area easily gets into the cockpit in f= light through the openings for the aileron pushrods and control column.=A0 = I fixed that one by replacing the cork and putting some proseal under the h= ead of each of the screws - though I wish I had used RTV.=A0 That proseal w= ill be a real beotch if=A0I ever need to get that plate off again.
-I also found a number of very small leaks (residue) past a number of = the rivets on the quick build fuel tanks.=A0 In particular, the bli= nd rivets on the back side just ahead of the spar were prone to le= ak (about=A06 of those had some amount of 2-stroke residue).=A0 I put dabs = of proseal around each offender.=A0 I don't know if that fixed it (woul= d need to remove fuel tank again to check) but the leaks were small enough = to not really be a problem.
- On one cross country flight I nearly gassed myself with a di= rty rag.=A0 Some=A0pump operator=A0had spilled massive amounts of = fuel over each wing.=A0 Actually that=A0happens almost universally whenever= I let anyone else "top it off" as those RV tanks go much faster = when near full.=A0 Now I always either do it myself or specify the number o= f gallons to put in each tank.=A0 Anyway, there were no rags at the pump so= I used one of my own and without thinking I tossed it in back.=A0 Passing = through 10,000 ft the smell was so strong I was about to puke before I fina= lly was able to reach the rag and seal it in the ice chest.=A0 Smaller amou= nts of spilled gas on a rag make less obvious sources of faint fuel odor.
- I bought a nifty little go-ped scooter that fits in the back of the = -6 and is fun to use around airports and for small trips.=A0 But on my last= cross country I thought I had developed some new (and strong)=A0fuel leak = until I realized that the tank on the go-ped was probably venting as I went= higher.
=A0
Hope that helps :-)

--
David (mostly now free of fuel smell) Leonard

Turbo = Rotary RV-6 N4VY
http://N4VY.Ro= taryRoster.net
http://RotaryRost= er.net

On Fri, Sep 25, 2009 at 7:48 PM, Mike Wills <rv-4mike@cox.net&= gt; wrote:
This is one of those frustrating littl= e issues. In ground running I dont notice it, but in flight I smell gasolin= e in the cockpit. I've run it on the ground trying to detect leaks and = cant find any at all. Anyone got a suggestion for some sort of a sniffer or= telltale I could put at all the connections that would show evidence of le= aking?
=A0
Mike Wills
RV-4 N144MW
<= /blockquote>



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