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: "Charlie England ceengland7@gmail.com" Received: from mail-ed1-f52.google.com ([209.85.208.52] verified) by logan.com (CommuniGate Pro SMTP 6.3.11) with ESMTPS id 1020984 for flyrotary@lancaironline.net; Tue, 24 May 2022 09:07:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.208.52; envelope-from=ceengland7@gmail.com Received: by mail-ed1-f52.google.com with SMTP id s3so22955353edr.9 for ; Tue, 24 May 2022 06:07:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=I542Ol3ZO7S9CNbUB5ZsXAVc0LUE8F82yN5OJ4GK7yI=; b=JBEwcFgYbcyrMfve/eWEKW32TXaIov53E3FbogSOxFufaw1sh+jWX17DBPk1a6Hwxi ocibCjto/7FCODjAemYZYNdFkLkg3lB7UZx4fVBfsCEdcnfCkJouZqx4RCr5p3chyekI YxHackneKdjZ5K4hXNRt9Z4jIrVcJ4Kqju4GARMUiXFJAK7hDkGsUjFDncK5H0lkEMgt zqtdmEXKweBS1iyRaPynIh19CVuwJPetYNVj6+gpA0dEG5VOyHGu9SpINRiSfvp8bw9J iBuq6RAH8kZx+kXkzbekJaxzwo9URRBuoENP9TXNGP78fNyA/HhnptBIBiKnlGhSoTuf TCJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=I542Ol3ZO7S9CNbUB5ZsXAVc0LUE8F82yN5OJ4GK7yI=; b=Q8T+QYgYymQnjfu+I+ThodPryJWB67vTurYACfFQsL/0+Dc2ZAcZ7nWRRgIgIrFFcw sM8NjEtDHv9kRuzcLAtKZPhp6AePc/vzj4F6lqXaXoPGPbiM07t+7baj1VAq1mavwZvF Rayl1YGJ/u4ITRJygaTMhKLV/QJDI13aNnaART7YoXdd2ss8bms/9J36cdKt/KoKqGXI Gv7rR6RJMd1tuYiMvNMIP+7IXzkmzeos6yMhKtK4OFeExu4yJK8Xi0ASVDLITS+GKz8n Ipm7wgRxDeR2URg6C8SYgLymGFUMffQSsl8XJmy6TZ8ymakY39VZyMjNydbO6A8Aruz9 JWtQ== X-Gm-Message-State: AOAM531jFO+DEcjo/POcsIsJLm3aQhP3zC79FHwHBAg+CRYwt9b0Ncjw 9gBUzbIbmUPQiowSaHHbjCEqUoH1XPyzdjGt3oQakSCv X-Google-Smtp-Source: ABdhPJzHgGqResHXhN3CiMNZiXhjIBU+H69laRcUg+NbXiZrOUdN+QaD3Zii48lCY5+HXGbN8VYSyfHLj+WN1Kro1Ns= X-Received: by 2002:a05:6402:75a:b0:42a:bbb9:504c with SMTP id p26-20020a056402075a00b0042abbb9504cmr29166125edy.348.1653397657150; Tue, 24 May 2022 06:07:37 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: Date: Tue, 24 May 2022 08:02:56 -0500 Message-ID: Subject: Re: [FlyRotary] Re: Fuel pressure trending lower. To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="00000000000006e83205dfc1a4ef" --00000000000006e83205dfc1a4ef Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Might be a little bit of a tangent, but frequent 400 hr life on Walbro pumps sounds off-nominal. They're used in a lot of modded cars, and a quick interweb search for 'lifespan' showed guys talking about 8-10 years, in cars (probably 100k+ miles). 400 hrs in a car would be, at most, ~24,000 miles, and I suspect the 'tuners' would give up on the pump pretty fast if they were only getting 20-30K miles of life from them. Charlie On Mon, May 23, 2022 at 3:38 PM David Leonard wdleonard@gmail.com < flyrotary@lancaironline.net> wrote: > Finn, > Where is your fuel filter located? Mine in downstream of the pump, but > before the fuel injectors. Fuel pressure gauge is just upstream of the > filter for me, which I now realize is sub optimal but does provide good > info about the state of the fuel filter. The pressure starts going up as > the filter clogs. > > I also have a fuel flow sensor on my return fuel line, which has turned > out to be a great troubleshooting tool and reflects the overall health of > the fuel system. > > I am using the walbro pumps that Tracy recommended. I bought 10 of them > once to have a supply on hand because I never again want to delay replaci= ng > them when I see the performance start to degrade. For me, the first sign > would be decreasing return flow. It more or less seems to linearly > decrease with the total time on the pump. For me, the pressure starts > dropping as the return flow gets closer to zero. I have taken to replaci= ng > the pump earlier in the process, like 50% reduction in return flow. With > pumps like the walbro, current demand to the pumps goes up as the flow go= es > down. At some point the current demand will blow the breaker and termina= te > the flight. I would guess that fuel pumps seem to last 400 hrs or so. > This is an improvement since I installed a larger fuel filter to keep dow= n > the pressure differential. > > If your pumps are similar and your fuel pressure is dropping at the > injector, and the problem is not a clogging fuel filter, then I suggest y= ou > replace the pump ASAP. They seem fairly susceptible to damage from > particulate contamination or being run while dry. > > Cheers, > Dave Leonard > > On Mon, May 23, 2022 at 9:04 AM Steven W. Boese SBoese@uwyo.edu < > flyrotary@lancaironline.net> wrote: > >> Finn, >> >> What the fuel pump should be flowing and what it is flowing may be two >> different things and needs to be evaluated before being "comfortable". >> That is why I would encourage you to measure the actual flow rate if you >> can do it safely. When I left MS71 in May of 2017 following Charlie's >> rotary fly-in, my 13B burned 18 gal/hr on take-off and initial climb at >> 5800 RPM and initial OAT of 80 degrees F. Your set-up likely would requ= ire >> this much or more. This was the indication from a Flowscan turbine type >> sensor which has been demonstrated to be accurate. The flow measurement >> would just be a next step in the investigation. If the flow rate is not >> what is what it should be, then determining why would follow. The >> replacement pump should be helpful in this regard. >> >> If you recover the fuel being bypassed by the regulator, bubbles in that >> fuel will not necessarily indicate air leaking into the fuel drawn into = the >> pump. The process of dropping the pressure when the returned fuel passe= s >> through the regulator, causes dissolved air in the fuel to separate. >> Bubbles in this flow will be obvious. If fuel is drawn from a small >> reservoir (< a gallon or so) and returned to that same reservoir where t= he >> bubbles are allowed to escape to the surface, the bubbles will eventuall= y >> disappear as the fuel is degassed. Degassing all the fuel from the wing >> tank is unlikely to occur due to the large volume of fuel and the large >> surface area of the fuel in the tank. This is why returning bypassed fu= el >> directly to the fuel pump intake or to a small unvented header tank (whe= re >> the separated air is allowed to accumulate) may not be the best practice= . >> >> FWIW >> >> Steve Boese >> >> >> >> >> ------------------------------ >> *From:* Rotary motors in aircraft on >> behalf of Finn Lassen finn.lassen@verizon.net < >> flyrotary@lancaironline.net> >> *Sent:* Monday, May 23, 2022 6:25 AM >> *To:* Rotary motors in aircraft >> *Subject:* [FlyRotary] Re: Fuel pressure trending lower. >> >> https://vansairforce.net/community/showthread.php?t=3D168793 >> >> The GSL414 should be flowing more than 30 GPH at 40 psi. More than doubl= e >> of what I need. Does that qualify as "a comfortable amount"? >> >> I have a new one on order. I'll try to hook up my own test. >> >> Finn >> >> On 5/22/2022 11:00 PM, Sboese sboese@uwyo.edu wrote: >> >> Finn, >> >> It seems to me that the problem you=E2=80=99re seeing is consistent with= the >> capacity of the pump not being sufficient for the max flow required by t= he >> engine and the pump flow capacity is decreasing with use. You appear to >> have checked everything but the flow capacity of the pump under normal >> system pressure which is what you really need to know. If you can diver= t >> the returning fuel flow from the pressure regulator to a measuring vesse= l >> and and collect that fuel for an accurately measured time, the pump flow >> rate can be calculated. This flow rate should be greater than the maxim= um >> required by the engine by a comfortable amount. >> >> My apologies in advance if this is obvious. >> >> Steve Boese >> >> On May 22, 2022, at 8:05 PM, Stephen Izett stephen.izett@gmail.com >> wrote: >> >> =EF=BB=BF >> >> =E2=97=86 This message was sent from a non-UWYO address. Please exercise= caution >> when clicking links or opening attachments from external sources. >> >> Hi Finn >> >> Thanks for the reminder of my pump issue. >> Yes, you chose more wisely the pump capacity. Mine were way overkill. >> >> So I=E2=80=99m thinking options are: >> 1. Fuel Pressure transducer fault - No - as this was confirmed by the >> mixture monitor and tune going out. >> 2. Power supply to pump via fault in termination or switch current path = - >> Unlikely, given the slow reduction - I would imagine a faulty connection >> would create a less uniform symptom. >> 3. Alternator Battery voltage/current reduction over time - No - You >> would see this in the log. >> 4. Significant Fuel leak - No - Would think this would have become >> obvious on inspection and not intermittent. >> 5. Fuel Regulator - They are pretty simple but unsure if they can fail >> with this symptom? >> 6. Fuel filter blockage - Certainly this would have to be an obvious, bu= t >> I take it you swapped this out. >> 7. Pump internal failure - >> Electrical - ? >> Mechanical breakage - ? >> Flow Path - blockage - unlikely if filtered effectively >> >> Where is your pressure transducer in relation to Reg/Any post pump >> filtering/Flow Transducer/Rail? >> >> If fuel regulator and filters can be discounted, I=E2=80=99m struggling = to trust >> the pump. But your test had it sounding in good shape and to spec. >> >> So frustrating. >> >> Cheers >> >> Steve >> >> >> >> >> >> On 23 May 2022, at 8:44 am, Finn Lassen finn.lassen@verizon.net < >> flyrotary@lancaironline.net> wrote: >> >> Thanks Steve. >> >> >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 i= n >> the inlet). >> >> So this afternoon I ran the pump for about an hour. Amp draw from 3.04 t= o >> 286 depending on voltage. Pressure between 43 and 40 psi (also depending= on >> voltage). No noticeable degradation. 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 signs of a failing pump in terms of >> higher current draw and less pressure. >> >> 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. >> >> Finn >> >> On 5/21/2022 9:01 PM, Stephen Izett stephen.izett@gmail.com wrote: >> >> 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 incase of >> failure. >> I plan to instal a comparator relay board in fuel pressure circuit to >> automatically bring on backup pump and failure indicator. >> So testing before flight becomes - switch off and back on main engine >> pump. This will save amps and wear of backup pump. >> When I switch off a pump at WOT the engine dies pretty much >> instantaneously and don't want to be fiddling with a restart in the Glas= air >> which 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 di= d >> not come up in power when advancing to full throttle. Noticed mixture re= al >> 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 pressur= e >> has been trending lower through each flight -- more pronounced on longer >> flights (40+ minutes). More and more pronounced over the months and beca= me >> really noticeable over last month. Could explain why mixture tuning >> *appeared* to have changed. Nice to have engine logs from practically >> each flight. >> >> But 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 regulator back to the tan= k. >> >> My secondary (backup) pump is a GSL393. When turning that on, fuel >> pressure comes back up to where it needs to be. >> >> Anyone have experience with failing or weak EFI pumps, particularly the >> GSL414? >> >> Finn >> >> >> >> >> >> --00000000000006e83205dfc1a4ef Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Mig= ht be a little bit of a tangent, but frequent 400 hr life on Walbro pumps s= ounds off-nominal. They're used in a lot of modded cars, and a quick in= terweb search for 'lifespan' showed guys talking about 8-10 years, = in cars (probably 100k+ miles). 400 hrs in a car would be, at most, ~24,000= miles, and I suspect the 'tuners' would give up on the pump pretty= fast if they were only getting 20-30K miles of life from them.

Charlie

On Mon, May 23, 2022 at= 3:38 PM David Leonard wdleonard@gma= il.com <flyrotary@lan= caironline.net> wrote:
Finn,
Where is your fuel filter located?= =C2=A0 =C2=A0Mine in downstream of the pump, but before the fuel injectors.= =C2=A0 Fuel pressure gauge=C2=A0is just upstream of the filter for me, whic= h I now realize is sub optimal but does provide=C2=A0good info about the st= ate of the fuel filter.=C2=A0 The pressure starts going up as the filter cl= ogs.

I also have a fuel flow sensor on my return f= uel line, which has turned out to be a great troubleshooting tool and refle= cts the overall health of the fuel system.

I am us= ing the walbro pumps that Tracy recommended.=C2=A0 I bought 10 of them once= to have a supply on hand because I never again want to delay replacing the= m when I see the performance start to degrade.=C2=A0 For me, the first sign= would be decreasing return=C2=A0flow.=C2=A0 It more or less seems to linea= rly decrease with the total time on the pump.=C2=A0 For me, the pressure st= arts dropping as the return flow gets closer to zero.=C2=A0 I have taken to= replacing the pump earlier in the process, like 50% reduction in return fl= ow.=C2=A0 With pumps like the walbro, current demand to the pumps goes up a= s the flow goes down.=C2=A0 At some point the current demand will blow the = breaker and terminate the flight.=C2=A0 I would guess that fuel pumps seem = to last 400 hrs or so.=C2=A0 This is an improvement since I installed a lar= ger fuel filter to keep down the pressure differential.

If your pumps are similar and your fuel pressure is dropping at the i= njector, and the problem is not a clogging fuel filter, then I suggest you = replace the pump ASAP.=C2=A0 They seem fairly susceptible to damage from pa= rticulate contamination or being run while dry.

Ch= eers,
Dave Leonard

On Mon, May 23, 2022 at 9:04 AM Steven W.= Boese SBoese@uwyo.edu= <f= lyrotary@lancaironline.net> wrote:
Finn,

What the fuel pump should be flowing and what it is flowing may be two diff= erent things and needs to be evaluated before being "comfortable"= .=C2=A0 That is why I would encourage you to measure the actual flow rate i= f you can do it safely.=C2=A0 When I left MS71 in May of 2017 following Charlie's rotary fly-in, my 13B burned 18 gal/hr=C2= =A0on take= -off and initial climb at 5800 RPM and initial OAT of 80 degrees F.= =C2=A0 Your set-up likely would require this much or more.=C2=A0 This was the indication from a Flowscan turbine t= ype sensor which has been demonstrated to be accurate.=C2=A0 The flow measu= rement would just be a next step in the investigation.=C2=A0 If the flow ra= te is not what is what it should be, then determining why would follow.=C2=A0 The replacement pump should be helpful in this reg= ard.

If you recover the fuel being bypassed by the regulator, bubbles in that fu= el will not necessarily indicate air leaking into the fuel drawn into the p= ump.=C2=A0 The process of dropping the pressure when the returned fuel pass= es through the regulator, causes dissolved air in the fuel to separate.=C2=A0 Bubbles in this flow will be obvious.= =C2=A0 If fuel is drawn from a small reservoir (< a gallon or so) and re= turned to that same reservoir where the bubbles are allowed to escape to th= e surface, the bubbles will eventually disappear as the fuel is degassed.=C2=A0 Degassing all the fuel from the wing tank i= s unlikely to occur due to the large volume of fuel and the large surface a= rea of the fuel in the tank.=C2=A0 This is why returning bypassed fuel dire= ctly to the fuel pump intake or to a small unvented header tank (where the separated air is allowed to accumulate) ma= y not be the best practice.

FWIW

Steve Boese

=C2=A0


From: Rotary motors in aircraft <flyrotary@lancaironli= ne.net> on behalf of Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net= >
Sent: Monday, May 23, 2022 6:25 AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: Fuel pressure trending lower.
=C2=A0
https://vansairforce.net/community/showthread.php?t=3D= 168793

The GSL414 should be flowing more than 30 GPH at 40 psi. More than double o= f what I need. Does that qualify as "a comfortable amount"?

I have a new one on order. I'll try to hook up my own test.

Finn

On 5/22/2022 11:00 PM, Sboese sboese@uwyo.edu wrote:
Finn,

It seems to me that the problem you=E2=80=99re seeing is c= onsistent with the capacity of the pump not being sufficient for the max fl= ow required by the engine and the pump flow capacity is decreasing with use= .=C2=A0 You appear to have checked everything but the flow capacity of the pump under normal system pressure which is what y= ou really need to know.=C2=A0 If you can divert the returning fuel flow fro= m the pressure regulator to a measuring vessel and and collect that fuel fo= r an accurately measured time, the pump flow rate can be calculated.=C2=A0 This flow rate should be greater than t= he maximum required by the engine by a comfortable amount. =C2=A0

My apologies in advance if this is obvious.

Steve Boese=C2=A0

On May 22, 2022, at 8:05 PM, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:

=EF=BB=BF

=E2=97=86 This message was sent from a non= -UWYO address. Please exercise caution when clicking links or opening attac= hments from external sources.


Hi Finn

Thanks for the reminder of my pump issue.=C2=A0
Yes, you chose more wisely the pump capacity. Mine were way overkill.<= /div>

So I=E2=80=99m thinking options are:
1. Fuel Pressure transducer fault - No - as this was confirmed by the = mixture monitor and tune going out.
2. Power supply to pump via fault in termination or switch current pat= h - Unlikely, given the slow reduction - I would imagine a faulty connectio= n would create a less uniform symptom.
3. Alternator Battery voltage/current reduction over time - No - You w= ould see this in the log.
4. Significant Fuel leak - No - Would think this would have become obv= ious on inspection and not intermittent.=C2=A0
5. Fuel Regulator - They are pretty simple but unsure if they can fail= with this symptom?
6. Fuel filter blockage - Certainly this would have to be an obvious, = but I take it you swapped this out.
7. Pump internal failure -
Electrical - ?
Mechanical breakage - ?
Flow Path - blockage - unl= ikely if filtered effectively

Where is your pressure transducer in relation to Reg/Any post pump fil= tering/Flow Transducer/Rail?

If fuel regulator and filters can be discounted, I=E2=80=99m strugglin= g to trust the pump. But your test had it sounding in good shape and to spe= c.

So frustrating.

Cheers

Steve





On 23 May 2022, at 8:44 am, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:

Thanks Steve.

>From your March/April 2017 posts it was a GSL392 that failed (high curr= ent draw/low pressure, even after you removed the insect you found in the i= nlet).

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 (also depending on = voltage). No noticeable degradation. Of course the difference with this tes= t 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.
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.

Finn

On 5/21/2022 9:01 PM, Stephen Izett stephen.izett@gmail.com wrote:
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 incase of = failure.
I plan to instal a comparator relay board in fuel pressure circuit to = automatically bring on backup pump and failure indicator.
So testing before flight becomes - switch off and back on main engine = pump. This will save amps and wear of backup pump.
When I switch off a pump at WOT the engine dies pretty much instantane= ously and don't want to be fiddling with a restart in the Glasair which= glides like a brick with the gear out in the breeze.

Regards =C2=A0
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 di= d not come up in power when advancing to full throttle. Noticed mixture rea= l lean. Checking fuel pressure as low as 28 psi (normally 35 and up to 40 a= t full throttle).

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

But 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 regulator back to the tank.=

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

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

Finn





--00000000000006e83205dfc1a4ef--