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No problem. Just pull over to the side of
the road, clean it out and carry on. !
I don’t get it. Isn’t proven aircraft
grade good enough? We’re not talking megabucks.
Jim
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf
Of Jeffrey W. Skiba
Sent: Monday, July 28, 2014 12:06
PM
To: Lancair Mailing List
Subject: [LML] Re: Gascolators and
fuel lines.
Another option is:
http://www.weldonracing.com/product/25/EFI_and_Carbureted_Filter_Assembly.html
From: Lancair
Mailing List [mailto:lml@lancaironline.net] On
Behalf Of Bill Bradburry
Sent: Monday, July 28, 2014 11:16
AM
To: Lancair Mailing List
Subject: [LML] Re: FW: [LML] Re:
Gascolators and fuel lines.
Mark,
I would not recommend this type of filter
for an airplane.
I couldn’t find a part number for
the replacement filter media for this filter. The filter part number
itself is different depending on whether you want cellulose at 10 microns or
steel at 100 microns. I bought a similar diameter filter that was three
and a half inches long and the filter media was a round flat screen that the
fuel flowed through. The filter media was about three quarters, seven
eighths inch in diameter and would take nothing to plug it up completely, which
it did after about an hour of running. It was a black sludgey material
that I think came from my incomplete cleaning of the fuel hoses that I made up
after cutting to length and installing the hose ends. Anyway after I saw how
easily they were to plug, I got rid of them and installed a fuel filter of the
style of an oil filter. They have a lot of filter media and will plug
very slowly so you should be able to see your pressure or flow dropping for
quite some time before you would lose the engine.
I am not recommending this particular
filter, but it is of the type I would recommend.
http://www.summitracing.com/parts/sum-g1507/overview/
Bill
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf Of Mark Sletten
Sent: Monday, July 28, 2014 4:42
AM
To: Lancair Mailing List
Subject: [LML] Re: FW: [LML] Re:
Gascolators and fuel lines.
Gang,
The vast majority of answers on this subject have focused on the
filtration benefits of the gascolator. I think Dennis Johnson's observations
are spot on. If one carefully sumps the tanks (ensuring the aircraft is sitting
on a level surface) prior to engine start it would be nigh impossible to get a
coherent slug of water large enough and to interfere significantly with engine
operation. This is especially true for fuel injected Continental installations,
where a significant portion of the fuel pumped to the engine is unused and
returned to the tank. Is it possible for a very large slug of water to remain
coherent in five gallons of fuel while agitated by aircraft motion and fuel
recirculation? I suppose it is, but it seems unlikely to me.
That aside, no one has mentioned ever finding water in the gascolator
of their Lancair. Which makes sense, because in order to do so water would have
flow uphill while on the ground, or remain separated enough from the fuel to
fall out while flowing thru the gascolator at something approaching a
half-a-gallon per minute while the engine is running.
Regarding the filtration capabilities of the gascolator; I've emailed
Andair for more information on the specifications (filtration level, filter
material area, max fuel flow, etc.), but they have yet to respond. If anyone
has this information I would greatly appreciate it.
Kevin Stallard suggested the gascolator would appear to be a better
option as a filter than an inline style. The type of inline filter I'm talking
about is not your prototypical one-inch diameter, one-inch long plastic
see-thru filter we've all seen on our lawnmowers. I talking about something
more like this:
This filter is 1.75" in diameter and 6.25" long. If the
filtration media was a simple cylinder that size would yield 30+ square inches
of filtration area. Since the media is pleated (much like your typical oil
filter), the filtration area is actually much larger. Maximum flow rate is 150
gph, which is more than three times that required for an IO-550. That suggests
this filter could be two-thirds clogged with crud and still have adequate fuel
flow. And let's not forget there would be one filter for each tank; if one
clogs I can still switch tanks.
Additionally, this isn't a throw-one-in-and-hope-it-works scenario.
These filters would be installed in a location making it exceptionally easy to
remove for inspection/servicing--something that would occur following every
engine run up to first flight. My reasoning is that such a test regimen will
reveal any problems of the type mentioned here.
On Thu, Jul 24, 2014 at 4:39 PM, John B <2thman1@gmail.com>
wrote:
Like most of you who responded I would not give up the gascolator.
Have done two annuals since flying and both times have found almost a
teaspoon of white fuzzy stuff. Fiberglass particles I'm virtually certain,
and I thought I had done a perfect job of cleaning out the tanks before
first flight.
Adam,
My experience is the same as yours. I often found/drained water out of my old
Cherokee tanks, and MANY rental airplanes as well. All were parked outside, and
I think avgas came with a certain amount of “water added” in the
old days… L
I’ve never
found any water in the gascolator of my IV-P, so the fuel doesn’t
have/collect any water…or it’s going through the engine and being
vaporized--which I think unlikely. I know the gas caps are MUCH better than the
old Cherokee “stoppers,” and I rarely park the Lancair outside
these days.
Like you, I was
meticulous in cleaning/keeping the fuel tanks/lines clean during fabrication
and through flight test. I still collected some small amounts of carbon fuzz,
and a few bits of aluminum in the gascolator during testing, and at the first
two condition inspections. Almost undetectable bits of something for the last
three, not enough to even identify when poured onto a piece of white
paper… So the gascolator/filter is probably not serving a useful function
today…but deleting it would be like throwing away the spare tire in my
car, IMHO… I carry a few critical spare parts in my airplane for the same
reason…
Bob
From: Lancair Mailing
List [mailto:lml@lancaironline.net]
On Behalf Of Adam Molny
Sent: Thursday, July 24, 2014 1:30
PM
To: Lancair Mailing List
Subject: [LML] Re: Gascolators and
fuel lines.
Hi Mark –
Our planes are kept in a heated hangar so
there’s no opportunity for water in the system from rain or condensation.
Back when I was renting Cessnas and Pipers I did occasionally drain water from
the gascolator. Those planes were kept outside.
The lowest point in the Legacy fuel system
is the fuel selector valve, but it’s not designed to capture water or
sediment like a gascolator. Your notion that the fuel flows too fast for water
to settle out is difficult to prove or disprove. I always envisioned tiny globs
of water flowing out of the fuel tanks and coalescing into a large glob of
water in the gascolator. The real test would be to pour a cup of water into one
wing tank, run the engine at high power, and see where the water ends up (in
the gascolator, out the tailpipe, or back to the fuel tank). However,
deliberately adding water to the fuel system seems like a bad idea so I’m
not going to try it.
I think you are saying you want fuel
filtration but there’s no point in having water separation since a
gascolator won’t work. Can you be 100% certain that you will never get
water in your system? What about flying through rain with a loose fuel cap?
What about being parked outside at Oshkosh for a week? If you do get water in
the system, where will it go? I hate to fall back on the “It’s
always been done that way” argument, but gascolators exist for a reason.
For all the Legacy drivers out there: Have
any of you ever discovered water in the gascolator?
Good discussion!
From: Mark Sletten [mailto:mwsletten@gmail.com]
Sent: Thursday,
July 24, 2014 9:15 AM
To: Adam Molny
Subject: Re:
Gascolators and fuel lines.
Adam,
I wasn't questioning the value of fuel filtration, just whether a
gascolator is the best choice. As I understand it, the gascolator provides a
means to filter the fuel and a low point to catch water that may have gotten
into the fuel system. There are several arguments against using one for the
Legacy.
- In the Legacy the gascolator is not the lowest
point in the fuel delivery path from the tank to the engine, so water in
the tank should not flow to the gascolator before turning on the pumps. (I
believe the same is true of the RV. Has your wife ever drained any water
from her gascolator?)
- Given the high fuel flow rate and recirculation
of unused fuel to the tank, it's unlikely the gascolator will remove any
water with the engine running.
- The gascolator in the engine compartment provides
a large surface area to add heat to the fuel which can contribute to vapor
lock. Lancair combats this with a heat shroud and blast air, adding weight
and complexity.
- The gascolator requires numerous fittings and
breaks in the fuel lines, adding to complexity, weight and the possibility
of fuel leaks.
Since the gascolator appears to be rather useless at removing water,
it's primary function for the Legacy is filtration. With so many other
filtration options available, it seems illogical to put a gascolator in the
engine compartment.
On Thu, Jul 24, 2014 at 7:12 AM, Adam Molny <Adam@validationpartners.com>
wrote:
Mark –
The gascolator provides a large reservoir
for capturing water and sediment. It also contains a fine screen with a fairly
large area that acts the final filtration element to keep junk out of your
carburetor or injector(s).
Case in point: my wife’s RV6-A
started showing small amounts of debris when sumping the fuel tank drains and
gascolator. We opened up the gascolator and found a small amount of debris at
the bottom of the bowl, and the screen was about 5% blocked. There was no
immediate danger, since the bowl would have to completely fill with debris and
the screen would have to be 100% blocked in order to kill the engine. It turned
out to be bits of fuel tank sealant flaking off.
My point here is that the gascolator acts
as a buffer and gives you lots of warning and lots of time to head off any
potential fuel contamination problem.
What is the argument for omitting the
gascolator on fuel injected engines?
-Adam Molny
Legacy N181AM 255hrs
From: Mark Sletten
[mailto:mwsletten@gmail.com]
Sent: Wednesday,
July 23, 2014 7:35 AM
Subject: Gascolators and fuel
lines.
Gang,
First: Gascolators. There is a great deal of debate around the web on
the benefits of a gascolator in fuel injected systems. What's the consensus
among Lancairians?
Second: I'm considering making my own engine compartment fuel lines. I
plan to build them up from scratch including the fire sleeve (or not if the
hose is sufficiently fire resistant). Anyone have a recommendation on the type
of hose to use?
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