X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "David COOK hoursaway1@comcast.net" Received: from resqmta-h1p-028588.sys.comcast.net ([96.102.200.10] verified) by logan.com (CommuniGate Pro SMTP 6.3.11) with ESMTPS id 1022808 for flyrotary@lancaironline.net; Tue, 24 May 2022 19:17:44 -0400 Received-SPF: pass receiver=logan.com; client-ip=96.102.200.10; envelope-from=hoursaway1@comcast.net Received: from resomta-h1p-027913.sys.comcast.net ([96.102.179.200]) by resqmta-h1p-028588.sys.comcast.net with ESMTP id tVL1nTLqSoFeYtdmJnLvtd; Tue, 24 May 2022 23:17:27 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=20190202a; t=1653434247; bh=AKWRvH8Ji3NTT5k5U8aVNKuiFcMQRwsSgFwpcrb1oaA=; h=Received:Received:Date:From:To:Message-ID:Subject:MIME-Version: Content-Type; b=NJtoxYI2gciTJLBdK02hL3+cPPmy+U/FTKXIS8TvgVYUdo2kmTEypTjfvGQ4aIpr7 gOQtNRFR37ZmTFQR0hV4w03vF9/fjUW5HNvIU5CUt5PHeV/7rkGaMFhDY9EoPuTrBb dVf98j0Q9lg0mND3EpQL+9/tJAlY97AdZkPocEarGrBFMI8eMjrykmb28QyNSwvK1S oRdK2oG4HsX/ES/xPpOsXIO2qPwaRHL+ERzJlIIkuoUqcoi/t8qnwPByG9oey291TS ecbSFVW2lHOAcXshpBU1aQKqNkqgsV3SW8GROpeLUVWpIoifTYBO+C0rzJu5op3Z2t TlS0smuhxwzsA== Received: from oxapp-ch2f-80o.email.comcast.net ([96.117.82.147]) by resomta-h1p-027913.sys.comcast.net with ESMTPS id tdlwnhKShi0HWtdlwnXfw8; Tue, 24 May 2022 23:17:05 +0000 X-Xfinity-VAAS: gggruggvucftvghtrhhoucdtuddrgedvfedrjeeggddvtdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucevohhmtggrshhtqdftvghsihdpqfgfvfdppffquffrtefokffrnecuuegrihhlohhuthemuceftddunecunecujfgurhepfffhvffkjghfufggtgfrkgfoihesrgdtsggsredtjeenucfhrhhomhepffgrvhhiugcuvefqqffmuceohhhouhhrshgrfigrhidusegtohhmtggrshhtrdhnvghtqeenucggtffrrghtthgvrhhnpedvheetfeffkeejhfdukeeikeejueetueevhfekjeehvdduteeiueegjeeuleelfeenucffohhmrghinheprghvrghsthdrtghomhdpfhhlhihrohhtrghrhidrtghomhdplhgrnhgtrghirhhonhhlihhnvgdrnhgvthenucfkphepleeirdduudejrdekvddrudegjedpudeihedrvddvhedrheeirdejfeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhephhgvlhhopehogigrphhpqdgthhdvfhdqkedtohdrvghmrghilhdrtghomhgtrghsthdrnhgvthdpihhnvghtpeeliedruddujedrkedvrddugeejpdhmrghilhhfrhhomhephhhouhhrshgrfigrhidusegtohhmtggrshhtrdhnvghtpdhnsggprhgtphhtthhopedupdhrtghpthhtohepfhhlhihrohhtrghrhieslhgrnhgtrghirhhonhhlihhnvgdrnhgvth X-Xfinity-VMeta: sc=0.00;st=legit Date: Tue, 24 May 2022 19:17:04 -0400 (EDT) To: Rotary motors in aircraft Message-ID: <658123436.211302.1653434224235@connect.xfinity.com> In-Reply-To: References: Subject: Re: [FlyRotary] Re: Fuel pressure trending lower. MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_211301_1068777572.1653434224202" X-Priority: 3 Importance: Normal X-Mailer: Open-Xchange Mailer v7.10.5-Rev21 X-Originating-IP: ::ffff:165.225.56.73 X-Originating-Client: open-xchange-appsuite ------=_Part_211301_1068777572.1653434224202 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Thought those were rubber straps, but now I can see the elect. tape since I= had cataracts surgery this morning, both eyes and ears. > On 05/24/2022 8:19 AM Finn Lassen finn.lassen@verizon.net wrote: >=20 >=20 > Interesting. I do think I have star washers between screw heads and r= ing terminals. But yes, path is via the stainless steel screws, nut plates = and alum angle riveted to side skins. Packing crate steel straps wrapped wi= th electrical tape. >=20 > But, dang, you win that bet! I just tried and could easily turn the t= erminals. >=20 > Should have done a bit of extra work and installed separate nutplates= for ground screws! Seems drilling a couple of #8 holes is indicated. >=20 > Good eyes David! >=20 > Finn >=20 > On 5/23/2022 6:18 PM, David COOK hoursaway1@comcast.net mailto:hoursa= way1@comcast.net wrote: >=20 > > > Move pump grounds between rubber straps, solid on alu= m. bracket. Motors like clean elect. pathways. I bet you could grab and tur= n those terms on that rubber.=20 > >=20 > > > > > On 05/23/2022 9:20 AM Finn Lassen finn.la= ssen@verizon.net mailto:finn.lassen@verizon.net mailto:flyrotary@lancaironline.net wrote: > > >=20 > > >=20 > > > Traditionally the "tunnel" in the RV-4 is between your fe= et and legs. > > >=20 > > > The "wells" I'm talking about are just forward of the mai= n spar. Their covers or lids are mainly used to step on or slide your heels= on when sitting down, if not using the seat to stand on. > > >=20 > > > Finn > > > =20 > > > On 5/22/2022 10:42 PM, Charlie England ceengland7@gmail.c= om mailto:ceengland7@gmail.com wrote: > > >=20 > > > > > > > FWIW, neither of my purchased= -4s had covers on the tunnel. > > > >=20 > > > > On 5/22/2022 9:03 PM, Finn Lassen finn.lassen@veriz= on.net mailto:finn.lassen@verizon.net wrote: > > > >=20 > > > > > > > > > Factors in my fav= or: > > > > > Pumps are located opposite side from exhaust. > > > > > Pumps are elevated about 1.5" from floor (pla= stic cradles). > > > > > However, very likely that those enclosed "foo= t wells" heat up. > > > > > Definitely need to investigate that. > > > > > I guess I could even remove the cover (lid) a= nd just feel with my hand during flight. > > > > > Seems to be some discussion whether those cov= ers are structural or not. Tracy flies without them. Others have hinged the= m for storage. > > > > >=20 > > > > > Finn > > > > >=20 > > > > > On 5/22/2022 9:13 PM, Charlie England ceengla= nd7@gmail.com mailto:ceengland7@gmail.com wrote: > > > > >=20 > > > > > > > > > > > Since= it's a positive displacement pump, pumped volume should be very similar (a= t the same supply voltage) whether the engine consumes any fuel Temp is obv= iously a variable. RV4 floors get hot; at least when powered by a Lyc. ;-) > > > > > >=20 > > > > > > On 5/22/2022 7:44 PM, Finn Lassen finn.= lassen@verizon.net mailto:finn.lassen@verizon.net wrote: > > > > > >=20 > > > > > > > > > > > > > = Thanks Steve. > > > > > > >=20 > > > > > > > From your March/April 2017 posts = it was a GSL392 that failed (high current draw/low pressure, even after you= removed the insect you found in the inlet). > > > > > > >=20 > > > > > > > So this afternoon I ran the pump = for about an hour. Amp draw from 3.04 to 2.86 depending on voltage. Pressur= e between 43 and 40 psi (also depending on voltage). No noticeable degradat= ion. Of course the difference with this test is that no fuel went to engine= -- all recirculated through pressure regulator and back to tank. But no si= gns of a failing pump in terms of higher current draw and less pressure. > > > > > > >=20 > > > > > > > I guess I should put a temp probe= on the pump and see what it reads during flight to see if that could be a = factor. > > > > > > >=20 > > > > > > > Finn > > > > > > >=20 > > > > > > > On 5/21/2022 9:01 PM, Stephen Ize= tt stephen.izett@gmail.com mailto:stephen.izett@gmail.com wrote: > > > > > > >=20 > > > > > > > > > > > > > > > Hi Finn > > > > > > > >=20 > > > > > > > > I had from memory a 393 fai= l. Can=E2=80=99t recall the symptoms sorry. > > > > > > > >=20 > > > > > > > > I test before takeoff and t= hen run both pumps below 2ooo ft incase of failure. > > > > > > > > I plan to instal a comparat= or relay board in fuel pressure circuit to automatically bring on backup pu= mp and failure indicator. > > > > > > > > So testing before flight be= comes - switch off and back on main engine pump. This will save amps and we= ar of backup pump. > > > > > > > > When I switch off a pump at= WOT the engine dies pretty much instantaneously and don't want to be fiddl= ing with a restart in the Glasair which glides like a brick with the gear o= ut in the breeze. > > > > > > > >=20 > > > > > > > > Regards =20 > > > > > > > > Steve Izett > > > > > > > >=20 > > > > > > > >=20 > > > > > > > >=20 > > > > > > > >=20 > > > > > > > >=20 > > > > > > > >=20 > > > > > > > > > > > > > > > > > = On 21 May 2022, at 10:30 pm, Finn Lassen fin= n.lassen@verizon.net mailto:finn.lassen@verizon.net wrote: > > > > > > > > >=20 > > > > > > > > > Recently I noticed my= fuel pressure being low. Noticed because engine did not come up in power w= hen advancing to full throttle. Noticed mixture real lean. Checking fuel pr= essure as low as 28 psi (normally 35 and up to 40 at full throttle). > > > > > > > > >=20 > > > > > > > > > Going over my engine = logs since first flight I now see that fuel pressure has been trending lowe= r through each flight -- more pronounced on longer flights (40+ minutes). M= ore and more pronounced over the months and became really noticeable over l= ast month. Could explain why mixture tuning appeared to have changed. Nice = to have engine logs from practically each flight. > > > > > > > > >=20 > > > > > > > > > But why? Pump getting= weaker? > > > > > > > > >=20 > > > > > > > > > My primary fuel pump = is a GSL414. I figured it was wasted energy to push way more fuel than need= ed through the pressure regulator back to the tank. > > > > > > > > >=20 > > > > > > > > > My secondary (backup)= pump is a GSL393. When turning that on, fuel pressure comes back up to whe= re it needs to be. > > > > > > > > >=20 > > > > > > > > > Anyone have experienc= e with failing or weak EFI pumps, particularly the GSL414? > > > > > > > > >=20 > > > > > > > > > Finn > > > > > > > > >=20 > > > > > > > > > > > > > > > > >=20 > > > > > > > >=20 > > > > > > > > > > > > > > >=20 > > > > > > >=20 > > > > > > > > > > > > >=20 > > > > > > https://www.avast.com/sig-email?utm_me= dium=3Demail&utm_source=3Dlink&utm_campaign=3Dsig-email&utm_content=3Demail= client&utm_term=3Dicon > > > > > > Virus-free. www.avast.com https://www.a= vast.com/sig-email?utm_medium=3Demail&utm_source=3Dlink&utm_campaign=3Dsig-= email&utm_content=3Demailclient&utm_term=3Dlink > > > > > >=20 > > > > > > > > > > >=20 > > > > >=20 > > > > > > > > >=20 > > > > > > >=20 > > >=20 > > > -- > > > Homepage: http://www.flyrotary.com/ > > > Archive and UnSub: http://mail.lancaironline.net:81/lists= /flyrotary/List.html > > >=20 > > > > >=20 > > >=20 >=20 ------=_Part_211301_1068777572.1653434224202 MIME-Version: 1.0 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable =20 =20
Thought those were rubber straps, but now I can see the elect. tap= e since I had cataracts surgery this morning, both eyes and ears.
On 05/24/2022 8:19 AM Finn Lassen finn.lassen@verizon.net <flyrotary= @lancaironline.net> wrote:


Interesting. I do think I have star washers between screw heads and rin= g terminals. But yes, path is via the stainless steel screws, nut plates an= d alum angle riveted to side skins. Packing crate steel straps wrapped with= electrical tape.

But, dang, you win that bet! I just tried and could easily turn the= terminals.

Should have done a bit of extra work and installed separate nutplat= es for ground screws! Seems drilling a couple of #8 holes is indicated.

Good eyes David!

Finn

On 5/23/2022 6:18 PM, David COOK hoursaway1@comcast.net wrote= :
Move pump grounds between rubber straps, solid on alum. bracket.= Motors like clean elect. pathways. I bet you could grab and turn those ter= ms on that rubber. =20
On 05/23/2022 9:20 AM Finn Lassen finn.lassen@verizon.net = <flyrotary@lancaironline.net> wrote:


Traditionally the "tunnel" in the RV-4 is between your feet and legs.= =20

The "wells" I'm talking about are just forward of the main spar. = Their covers or lids are mainly used to step on or slide your heels on when= sitting down, if not using the seat to stand on.=20

Finn=20
 =20
On 5/22/2022 10:42 PM, Charlie England ceengland7@gmail.com w= rote:=20
FWIW, neither of my purchased -4s had covers on the tunnel.=20

On 5/22/2022 9:03 PM, Finn Lassen finn.lassen@verizon.net= wrote:=20
Factors in my favor:=20
Pumps are located opposite side from exhaust.=20
Pumps are elevated about 1.5" from floor (plastic cradles).=20
However, very likely that those enclosed "foot wells" heat up.= =20
Definitely need to investigate that.=20
I guess I could even remove the cover (lid) and just feel with = my hand during flight.=20
Seems to be some discussion whether those covers are structural= or not. Tracy flies without them. Others have hinged them for storage.=20

Finn=20

On 5/22/2022 9:13 PM, Charlie England cee= ngland7@gmail.com wrote:=20
Since it's a positive displacement pump, pumped volume should be v= ery similar (at the same supply voltage) whether the engine consumes any fu= el Temp is obviously a variable. RV4 floors get hot; at least when powered = by a Lyc. ;-)=20

On 5/22/2022 7:44 PM, Finn Lassen fin= n.lassen@verizon.net wrote:=20
Thanks Steve.=20

From your March/April 2017 posts it was a GSL392 that failed = (high current draw/low pressure, even after you removed the insect you foun= d in the inlet).=20

So this afternoon I ran the pump for about an hour. Amp draw = from 3.04 to 2.86 depending on voltage. Pressure between 43 and 40 psi (als= o depending on voltage). No noticeable degradation. Of course the differenc= e with this test is that no fuel went to engine -- all recirculated through= pressure regulator and back to tank. But no signs of a failing pump in ter= ms of higher current draw and less pressure.=20

I guess I should put a temp probe on the pump and see what it= reads during flight to see if that could be a factor.=20

Finn=20

On 5/21/2022 9:01 PM, Stephen Izett stephen.izett@gmail.com wrote:=20
Hi Finn

I had from memory a 393 fail. Can=E2=80=99t recall the symptoms = sorry.

I test before takeoff and then run both pumps below 2ooo ft inca= se of failure.
I plan to instal a comparator relay board in fuel pressure circu= it to automatically bring on backup pump and failure indicator.
So testing before flight becomes - switch off and back on main e= ngine pump. This will save amps and wear of backup pump.
When I switch off a pump at WOT the engine dies pretty much inst= antaneously and don't want to be fiddling with a restart in the Glasair whi= ch glides like a brick with the gear out in the breeze.

Regards  
Steve Izett





On 21 May 2022, at 10:30 pm, Finn Lassen finn.lassen@verizon.= net <flyrotary@lancaironline.net> wrote:

Recently I noticed my fuel pressure being low.= Noticed because engine did not come up in power when advancing to full thr= ottle. Noticed mixture real lean. Checking fuel pressure as low as 28 psi (= normally 35 and up to 40 at full throttle).

Going over my engine logs since first flight I= now see that fuel pressure has been trending lower through each flight -- = more pronounced on longer flights (40+ minutes). More and more pronounced o= ver the months and became really noticeable over last month. Could explain = why mixture tuning appeared to have changed. Nice to ha= ve engine logs from practically each flight.

B= ut why? Pump getting weaker?

My primary fuel pump is a GSL414. I figured it= was wasted energy to push way more fuel than needed through the pressure r= egulator back to the tank.

My secondary (backup) pump is a GSL393. When t= urning that on, fuel pressure comes back up to where it needs to be.

Anyone have experience with failing or weak EF= I pumps, particularly the GSL414?

Finn





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Homepage: http://www.flyrotary.com/=20
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