I think you'll find that the filter on a GA aircraft is disguised and
called a gascolator...but I could be wrong.
Inside my Rotec TBI is what is called a "last chance" filter. It
catches the bad stuff that would otherwise try to plug the 50-some
holes in the fuel discharge tube. These holes are reportedly .
010" (ten-thousandths of an inch) in diameter. I trust my Purolator
glass filters to keep the last chance filter, and thence the fuel
discharge tube, clean. I won't take my "pre-filters" out unless
something or someone proves that this is an incorrect design. And as
long as my gravity system flows more than twice what is needed by the
engine, that likelihood seems remote.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 805.4 hrs
Countdown to 1000 hrs--195 to go
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying (and learning)
On Nov 1, 2009, at 4:24 PM, Dwight Purdy wrote:
>
> I do not comment often but listen a lot.
> On this subject of fuel filters will say that in my 32 years of
> flying I have never seen a filter on a GA certified aircraft. That
> does not include any of the newer fuel injected ones. I have had a
> paper filter for a short time on my model II. While running premix
> and some ethanol in the fuel I was forced to land off field. Once
> that paper gets oil soaked water will not pass properly. Took the
> filter out and no problem.
>
> Dwight Purdy
> Model II
> ----- Original Message ----- From: "Lynn Matteson" <lynnmatt@jps.net>
> To: <kitfox-list@matronics.com>
> Sent: Sunday, November 01, 2009 11:42 AM
> Subject: Re: Re: Fuel Flow Problems, Again! (Vixen,
> Series-5)
>
>
>>
>> The only problem I have....and this is just a shade-tree mechanics
>> view...is the paper filter. It is said that they will clog if
>> water gets to them. I can see the benefit of not having a filter
>> in the line to the header tank, as the header tank DOES work like
>> a gascolator, and as such will catch (and allow for the sampling
>> of) any crud that might get there. I put the filters in my
>> down...to the header...lines because I wanted to see any crud
>> that just got into those lines from airport A, or airport B,
>> etc., or from my own 300- gallon tank at home.
>> Like you said, to each his own, and future or current builders
>> will be able to choose for themselves what they think is right.
>> And of course, each DAR will have his/her own views on what they
>> will allow.
>>
>> Lynn Matteson
>> Kitfox IV Speedster, taildragger
>> Jabiru 2200, #2062, 805.4 hrs
>> Countdown to 1000 hrs--195 to go
>> Sensenich 62"x46" Wood prop
>> Electroair direct-fire ignition system
>> Rotec TBI-40 injection
>> Status: flying (and learning)
>>
>>
>>
>>
>>
>>
>> On Nov 1, 2009, at 10:06 AM, Jim_and_Lucy Chuk wrote:
>>
>>> When I first got my Avid MK IV, I put filters on both sides
>>> between the wing tanks and the header tank. All was fine for a
>>> while (about 10-15 hrs) till one evening I took off from my
>>> strip and as I climbed out and got to 450', the engine started
>>> to miss and spit. I ended up landing in a neighbors field with
>>> no dammage to me or the plane. What had happened I found out
>>> the next day, was the filter on the tank I was using started to
>>> plug just a bit and so the flow was reduced. The engine never
>>> did die, but would not run up above about 4000 rpm. Durring the
>>> takeoff, it was turning up about 6200, and when the small header
>>> tank was emptied, things got "interesting". I posted this
>>> account on the Avid list, and Steve Winder, who ran the Avid
>>> factory for years said NEVER HAVE FILTERS BETWEEN THE WING TANKS
>>> AND THE HEADER TANK. He used all capitol letters also! He said
>>> that it takes very little to stop or slow the gravity flow, and
>>> ofcourse that is what caused my problem. He also said, that the
>>> header tank works as a gascolator to filter the fuel so the
>>> filters between the tanks aren't needed. I had a final filter
>>> between the header tank and the fuel pump, and so to gaurd
>>> against that one plugging and putting me in the trees, I put in
>>> a T in my fuel line and added a second filter alongside the
>>> first one and then a T back into the fuel line with a small
>>> valve to stop the flow through that filter. When I'm taking off,
>>> I open that valve and then close it after I get up to 750' or
>>> so. If the main filter ever starts to plug while in flight, I
>>> will open the valve for the second filter and the fuel will be
>>> able to flow through that one and I will stay out of the trees.
>>> So far that has worked good for me and I still have potentialy
>>> three filters to stop any crud getting to the carb. The header
>>> tank, the inline filter, pluss the backup filter which will only
>>> be used if the first inline filter plugs. To each his own, but
>>> this works for me. I have always used the Fram paper filters
>>> and they have worked good for me.
>>> Take care, Jim Chuk
>>>
>>> > Subject: Re: Fuel Flow Problems, Again! (Vixen,
>>> Series-5)
>>> > From: flyboytr@bellsouth.net
>>> > Date: Sun, 1 Nov 2009 05:43:45 -0800
>>> > To: kitfox-list@matronics.com
>>> >
>>> <flyboytr@bellsouth.net>
>>> >
>>> > Lynn,
>>> > ...you get to read a lot of email! [Shocked]
>>> >
>>> > I really don't want to get rid of my filters either. We are still
>>> only talking about one filter between a wing tank and the header
>>> tank. Once the fuel is in the header tank it should then benefit
>>> from the "suction" of the mechanical pump.
>>> >
>>> > My last two hurdles are removing the wing tank outlet fitting to
>>> check the finger strainers and cutting the root rib on the wing
>>> so the fuel line doesn't have to have a hump in it before
>>> descending down towards the header tank. Thanks again for all
>>> your input...always appreciated!
>>> >
>>> > Travis
>>> >
>>> >
>>> > Lynn Matteson wrote:
>>> > > I've read all your posts, and all of any mail that comes into
>>> my email box....I don't go to the "site".
>>> > >
>>> > > I doubt that the filter element is your problem. I'm keeping
>>> all of
>>> > > my filters, no matter how much certain engineers might (for me)
>>> > > confuse the issue with talk of surface tension, etc., my system
>>> flows
>>> > > fuel as long as there's fuel in the system to flow...nudge,
>>> nudge,
>>> > > wink, wink. ; )
>>> > >
>>> > >
>>> > > Lynn Matteson
>>> > > Kitfox IV Speedster, taildragger
>>> > > Jabiru 2200, #2062, 804.3 hrs
>>> > > Countdown to 1000 hrs--196 to go
>>> > > Sensenich 62"x46" Wood prop
>>> > > Electroair direct-fire ignition system
>>> > > Rotec TBI-40 injection
>>> > > Status: flying (and learning)
>>> > >
>>> > >
>>> > >
>>> > >
>>> > >
>>> > >
>>> > > On Oct 31, 2009, at 11:58 PM, FlyboyTR wrote:
>>> > >
>>> > >
>>> > > >
>>> > > >
>>> > > >
>>> > > >
>>> > >
>>> > :D
>>> >
>>> > --------
>>> > Travis Rayner
>>> > Mobile, AL
>>> > Skystar Vixen, N-789DF
>>> > Continental IO-240, Prince P-Tip Prop
>>> > ADI-II Autopilot
>>> > AnyWhereMap Navigation with weather
>>> >
>>> >
>>> >
>>> >
>>> > Read this topic online here:
>>> >
>>> > http://forums.matronics.com/viewtopic.php?p=270420#270420
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > >
>>> >
>>> >
>>>
>>> New Windows 7: Find the right PC for you. Learn more._-
>>> ============================================================ _-
>>> ============================================================ _-
>>> ===========================================================
>>
>>
>>
>>
>
>
