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Date: Fri, 23 May 2008 22:26:06 -0600
From: Bob White <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Fuel Filtering Problem
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Hi Bill,

When I first installed my system I had two of the small inline filters
which I think were similar to the ones you are using.  Somewhere along
the way, Buly mentioned a different filter.  It's about the same size
as an oil filter.  Summit Racing P/N PRM-81794.  It will hold many
times more contaminants than the small filters.  I felt comfortable
using one filter for both pumps.  If you have the room, you might
consider it.  No new ideas on where the contamination is coming from.

Bob W.


On Fri, 23 May 2008 22:06:39 -0400
"Bill Bradburry" <bbradburry@bellsouth.net> wrote:

> Kelly,
>=20
> The only pressure that I have available is driven by the fuel regulator. =
 It
> is set at 36 # at sea level pressure.  It should maintain that pressure w=
hen
> the engine is running WOT.  It would be less at idle.  I think 30.  When I
> turn the secondary pump on, the pressure goes up 2-3 lbs.
>=20
> Pressure on both sides of the filters would give an early warning of this
> problem, but I have not heard that anyone has installed that type of
> instrumentation.
>=20
> One thing that has come of this problem is that I have realized that I ha=
ve
> to way to turn the primary pump off since it is on the same switch as the
> EC-2 power.  I need to correct this as well. =20
>=20
> =20
>=20
> Bill B
>=20
>   _____ =20
>=20
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
> Behalf Of Kelly Troyer
> Sent: Friday, May 23, 2008 8:48 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Fuel Filtering Problem
>=20
> Bill,
>=20
>    What is the fuel pressure on the primary pump compared to the secondary
>=20
> pump ??.........These are rotary vane pumps (I do not know the composition
>=20
> of the vanes) and will gradually wear........They use the fuel to both co=
ol
> and
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> lubricate their bearings and vanes.........If run dry for any reason they
> will self destruct very rapidly and could produce the black sludge you are
> seeing.........
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> =20
>=20
> --
> Kelly Troyer=20
> "Dyke Delta"_13B ROTARY Engine=20
> "RWS"_RD1C/EC2/EM2=20
> "Mistral"_Backplate/Oil Manifold=20
>=20
>=20
>=20
>=20
> =20
>=20
> -------------- Original message from "Bill Bradburry"
> <bbradburry@bellsouth.net>: --------------=20
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>  I could use a little help on this problem.  I apologize for the length.
>=20
> =20
>=20
> My engine recently started to show signs of fuel starvation. Cutting out
> above about 3K rpm.  It would just seem to go from 3K to idle.  I was
> running on my primary fuel pump, so I turned on the secondary and the eng=
ine
> would start to run normally.  (Not like gangbusters, but NORMALLY.  My max
> static rpm has been about 52-5300 rpm and I have felt that it was not
> getting enough fuel to run up to my goal of 6K static)
>=20
> =20
>=20
> I decided that I had a filter plugged,  and fearing the gasohol that they
> are now selling all over Florida, I opened up my Gascolator.  It was ok. =
 I
> found a couple of wisps of white fibers.  Could be fiberglass dust, could=
 be
> spider  webs, something like that.  I don=92t think that I have had any
> gasohol in the plane, but it is probably possible.  But the Gascolator was
> fine.
>=20
> =20
>=20
> I then opened up the JEGS inline filter on the primary pump and the eleme=
nt
> was covered with a black sludge.  It seemed to be almost completely block=
ed.
> This stuff looked like maybe it could have come from the inside of the SS
> braided hose. =20
>=20
> =20
>=20
> I checked the secondary pumps filter and it was fine.  I have not used th=
is
> secondary pump except on rare occasions to check for pressure changes,
> leaks, etc..
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> =20
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> But for that matter, I have only run three 5 gal cans of gas in the plane
> totally.  One 5 gal can in each wing, then another in the right side, and=
 I
> am now pulling out of the left tank which has the fourth 5 gal in it.
>=20
> =20
>=20
> So, like I said, I at first thought that it was a rubber residue from whe=
n I
> installed the hose ends on the Aeroquip hoses because it sort of looked l=
ike
> that.  Then as I drove home, I remembered that there was none of this stu=
ff
> in the Gascolator.  (I think that some should have made it there as there=
 is
> one -8 hose in front of the Gascolator)  There is only about a foot of -8
> hose in front of the fuel pumps after the Gascolator, so now I am thinking
> that maybe it came from the fuel pump.
>=20
> =20
>=20
> Is there anything inside the pump that could cause a black sludge if it
> started to crap out?  What would I look for to check if the pump is out or
> going out.  Has anyone else had any similar problem?  I recently heard a
> squealing sound from the area of the pumps, but at the time I thought that
> it was bubbles going through the pump.  I was close to empty on the right
> tank and thought that it was sucking air.  I switched tanks and the sound
> went away.
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> =20
>=20
> I have not yet checked my injectors.  Two  reasons:  I have no idea of how
> to do it and would not know what to look for.  Is the 40 micron screen fi=
ne
> enough to keep anything from getting plugged up in the injectors?  If not,
> what do I look for, and where?
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> =20
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> I would greatly appreciate some input as to your thoughts on this.  How
> would you proceed?
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> =20
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> My fuel system goes: Finger strainer in tank, =BD inch aluminum line to A=
ndair
> dual valve (switches both supply and return to same tank), Aeroquip -8 SS
> braided line, boost pump, Aeroquip -8 SS braided line, Andair Gascolator,
> Aeroquip -8 SS braided line about one foot to splitter to two fuel pumps,
> (these are the pumps that Tracy sells), each pump is followed by a JEGS
> billet in line fuel filter with a stainless 40 micron element.  Then a
> splitter to bring them back together to Aeroquip -6 SS braided line, prim=
ary
> injector rail, Aeroquip -6 SS braided line, secondary injector rail,
> Aeroquip -6 SS braided line, Aeromotive fuel pressure regulator, Aeroquip=
 -4
> SS braided line to the valve and back to the tank.  The tanks are fibergl=
ass
> with ProSeal.  This is a Lancair Legacy, Renesis engine.
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> =20
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> Thanks for the help.
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> =20
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> Bill B
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>=20


--=20
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