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without question!!!!
Rich
In a message dated 8/7/2012 10:30:01 A.M. Central Daylight Time,
msteitle@gmail.com writes:
Bottom
line is that engines need pressurized fuel to run. There are other
possible reasons other than a plugged fuel filter that may prevent pressurized
fuel from reaching the injectors, such as a worn out/defective fuel pump,
leaking/defective pressure regulator, plugged fuel tank vent, loose/cracked
fuel line connection, leaking fuel line, incorrect/corrupted MAP table, etc.
We are dealing with "fuel systems", not just fuel filters. A
throttle cable coming loose could be just as bad as a plugged fuel filter.
Seems prudent for us to monitor our fuel pressures, and land at the
first suitable airport and fix it if it is not up to spec. And change
the fuel filter at every annual, or sooner if you get some bad gas.
Mark S.
On Tue, Aug 7, 2012 at 9:39 AM, <ARGOLDMAN@aol.com> wrote:
Al,
Of course, what is not taken into account by the auto guys is that the
fuel flow of an aircraft is significantly greater than that of a car and
that old planes are still flying and don't have the opportunity to "pull
over to the side if the filter gets plugged totally or partially.
Now if, as part of a conditional inspection, the filter/pump were
removed inspected and cleaned, I personally would feel much better about
that installation.
Rich
In a message dated 8/6/2012 10:58:34 P.M. Central Daylight Time, alwick@juno.com writes:
Dave says:
<How does a filter "Self clean"?
I mentioned this a couple years ago. One of the guys called Bull
Sh__. Well, not really, but what he did was most impressive. He went to
local wrecking yard, bought two used coarse filters. They reside in the
fuel tank. I think he spent like $5 or so.
Then he puts it in bucket, no I think he has old aquarium. Attached a
pump to it. Then got some dirt and debris from yard and poured it on. As I
recall he could not get it to clog. But the self cleaning was obvious when
he added a little wave action and vibration to it.
If you take this a little further, you can actually measure pump flow
rate by timing how long it takes to fill jug. You can then look at jug
contents so see how fine it screens. You can add a simple altimeter and
measure pressure drop on pump inlet. Less pressure drop means that vapor
lock risk is reduced. Tons of stuff you can measure that no one knows.
I'd think you'd find it takes around 1 tsp to clog the traditional
aircraft filter...so planes crash. Yet it takes cups of dirt to clog the
filter used by every single car manufacturer. Gigantic safety improvement.
<How DO the car manufacturers overcome eventual filter
clogging/saturation? Just by making it so dang <large it never reaches
that point?
I think they discovered that the larger the surface area, the less
likely to clog. That's why they all have around 6 to 10 times more surface
exposed to wave action than the filters of yesteryear.
-al wick
----- Original Message -----
Sent: Monday, August 06, 2012 6:57
AM
Subject: [FlyRotary] Re: Fuel
Filters. Was: Rotary Forced Landing
For the ignorati among us, I must ask.
How does a filter
"Self clean"? How DO the car manufacturers overcome eventual filter
clogging/saturation? Just by making it so dang large it never reaches
that point?
Dave
On 8/6/2012 8:48 AM, Al Wick
wrote:
<how small of filtration do we need?
<size of a particle that will fit through the injector nozzle
easily?
Excellent questions. You have one resource that stands WAY above
others. What do the OEM vehicles use? They know precisely what the
optimum surface area is, optimum filtration size. Too fine, it clogs
needlessly. Too coarse, you increase risk of injector clog. Too little
surface area, it won't last. They even take into consideration unusual
needs, like people that operate at super high flow rates.
A few decades ago, cars would periodically suffer clogged
filters. Never happens any more because they have new tools to
optimize designs. For example, their course filter screen has around
10 times more surface area than any airplane filter. Self
cleaning, screen size optimized. So debris can't affect your
car. It's just brilliant.
I really worry about builders copying marginal fuel designs.
Unaware of how close they are to the failure threshold. You can fly
for years with marginal design, tell everyone "works great for me".
Unaware you are promoting failure.
-al wick
----- Original Message -----
Sent: Sunday, August 05, 2012
1:35 PM
Subject: [FlyRotary] Fuel
Filters. Was: Rotary Forced Landing
So my next question is how small of filtration do we
need? ie, what is the size of a particle that will fit through
the injector nozzle easily?
I was using the Earls sintered
bronze element at 35microns, but I also could use the SS screen
version at 85 mic. The Peterson in line 600 series is MUCH
more expensive and comes in 45, 60, and 100 micron SS
screens.
http://www.jegs.com/p/Peterson-Fluid-Systems/Peterson-600-Series-Fuel-Filters/1528539/10002/-1
Those do have more surface area but will be a hassle for me to
retrofit, and not sure they are worth 4x the price of the
earls. Lots of other brands I have not explored
yet.
I like the sintered bronze for strength and
durability. Other opinions?
Dave Leonard
On Sun, Aug 5, 2012 at 12:42 PM, David
Leonard <wdleonard@gmail.com> wrote:
Yea, mine is an Earls cleanable high pressure with maybe 10
sq cm worth of area. Will look into the Peterson.
Thanks Tracy. Dave Leonard
On Sun, Aug 5, 2012 at 10:48 AM, Tracy
<rwstracy@gmail.com> wrote:
Al probably means the filter that's on factory in-tank
pumps. OK, but very hard to implement on RV wet-wing
tanks. I used a gascolator for low side filter on my -4.
Worked OK and when it clogged, switching on the
backup pump with main pump caused the screen disk to collapse
and let fuel bypass it. which is better than no fuel at
all but not an ideal solution.
On the -8 i used a cleanable Peterson filter with
TONS of filter area, works great. That was a replacement
for the Summit Racing fuel filter with a filter element disk the
size of a nickel. It clogged up in about about 5 hours of
flight.
Yes, it was the high side filter. I don't have any
low side filters. Would be interested in a source for
the self-cleaning fool-proof low side filters that Al
mentions. -- David Leonard Turbo Rotary RV-6
N4VY http://N4VY.RotaryRoster.nethttp://RotaryRoster.net
On Sun, Aug 5, 2012 at 6:34 AM, Tracy
<rwstracy@gmail.com> wrote:
I assume Al is referring to the pump intake side
filter. So for the record, was it the
inlet side or the high pressure side filter that clogged?
( Both are needed ) >From the symptoms I'm guessing
high side but not sure.
BTW, nice job!
Tracy
Sent from my iPad
As long as your are rebuilding, tremendous safety
improvement by using same fuel filter method that all cars
use. No matter how much foreign material you throw at
it, it can't clog. It minimizes pressure drop, so
lower risk of vapor lock. Self cleaning filter. Self
priming pumps.
-Al Wick Cozy IV powered by RDM Subaru 3.0R.
Expert at failure prevention methods, N9032U 240+
hours from Portland, Oregon Glass panel design, Subaru
install, Prop construct, Risk assessment info: http://www.ez.org/pages/alwick/index.htm
----- Original Message
-----
Sent: Saturday,
August 04, 2012 1:38 PM
Subject:
[FlyRotary] Re: Rotary Forced Landing
Dave, having gone through recently what you just
experienced I would like to say GOOD JOB on getting down
safely and with such little damage. Anyway at 1500
AGL there isn't a lot of time ... obviously you made the
right choices.
Jeff
(Rebuilding my Ride)
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Sigh..
Yup, that was me. I have been
meaning to fess up. We were at about 1500 agl when
the fuses blew on my fuel pumps. I was in a close
formation of 40 aircraft at the time too. I think
I got some bad MOGAS somewhere in Iowa as I did
notice my fuel return flow creep downward but
didn't think it was a big problem.
On the
incident flight, a one hour formation flight from
SQI for a mass arrival at OSH, the return fuel
flow drifted down to zero. I actually though it
was a sensor problem. I didn't have the ability to
give it a lot of attention because we were in a
loose formation. Soon after we pulled it together
for a tight formation power switched off. I tried
to find a road, but quickly ran out of options and
put it down in a bean field. With the beans
hitting the flaps it brought me to a stop in about
200ft, just before I would have gone into the full
grown corn. As mentioned, wheel pants broke in
half but no other damage besides pulling bean
leaves out of every nook and cranny. The farmers
were very nice, and the stories are true... they
have attractive daughters. They were out there
barefoot in their Sunday best enjoying the
excitement. Helped me clean the fuel filter and
replace the fuses. Within a couple of hours I was
able to take off from one of their driveways as
they all waived good bye (but strangely, no one
took me up on my offer for a ride).
Landed
at OSH just before dark to a reserved parking
space and a very warm reception from the formation
group and friends. Great support from everyone all
around, though I am trying to avoid the obvious
new call signs they are trying to give
me.
--
David
Leonard
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David
Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net
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