Filter or Gascolator? KF5

[wildirishtime]

with a header tank behind the seat, does someone really need
a gascolator? Seems like a perfect sump sediment trap all on it's own.

If the answer is 'it still needs filtered' then what engine compartment
filter do you all use? pastic=meltable, glass=breakable, metal=not inspectable. What's a person to do????

~Wild

[Dorsal]

For me, no gascolator and a metal filter up in the engine compartment, not inspectable so I just dissect it when I change it.

[kitfox2009]

I installed a gascolator in the very lowest right hand corner on the firewall. The bowl projects out the bottom of the lower cowl about 1 inch. I have NO filters anywhere in the system and rely solely on the gascolator screen. I have just over 100 hours on this configuration with no difficulty. Just as a side note:: a gascolator is mandatory on Canadian homebuilts and my inspector would not allow any kind of an "in line" filter. He had experienced water in the fuel that swelled the filter elements and restricted the flow. So far the fine screen has done the job for me. I use 87 grade auto fuel exclusively and filter it when filling. To date we are able to get non ethanol fuel here. Hope it stays this way!

Don Hudgeon
Vixen 912UL IVO IFA.

[cap01]

wild , i have a gascolator , it was already installed when i acquired the kit . when i installed the fuel system i installed one of the glass take apart filters between the header outlet and the gascolator below the baggage sack . never had a good feeling about having a filter that could dump all my gas in the belly if it came apart . i have replaced it with the metal filter and feel better , just change it and toss it . as i recall the filter number crosses to a napa filter for not too many dollars .

[Dave S]

Wild Irishman,

Our series 7 is set up the same as Dorsal's plane - the header tank and a single steel case auto filter on the engine which is changed frequently. This is what the construction manual called for in 2005 - may be different now. I always cut then apart when replacing and have never found anything in them - may be that nothing has gotten past the header tank.

No way would I put a glass or plastic filter under the cowl on the engine. I have considered yanking a large diameter piece of firesleeve over the metal filter - more to keep the metal filter from being an under cowl heatsink - but it could serve as protection for the fuel system and filter.

There are additional ways a person can protect themselves from fuel contamination.

1) Starting with the fill - I use a large tractor funnel with a chamois over it - the chamois will catch extremely small particles - probably smaller stuff than a filter - and it will filter out water.
2) You can't keep stray bug parts from ramming down the gas cap air tubes - that is what the tank finger strainers are for - to catch the big bug parts that make it that far; however, small bug parts that go past the finger strainers won't settle out that well in the header tank so an inline filter or gascolator of some sort is needed to catch the floaters.
3) You can still get condensation contam in a fuel tank - normal preflight sumping at the tanks and header will keep a person informed as to what is collecting there - mostly any heavy particles and certainly water will end up in the bottom of the header tank. Water is easy to observe/separate/catch this way. A person really wants to catch the water at the header tank and keep it from accumulating to keep it from messing up a paper filter - too much water in a paper filter will seal it up pretty well.
4) The great think about a gascolator is it has a metal screen which; although it can plug up with too much dirt - is not succectible to water blocking like a paper filter is. Metal screens are better than paper. I don't have a gascolator but that is the ideal and what I would prefer.
5) Carburetor fuel bowls should be opened and checked periodically to see what kind of junk may or may not be collecting in them. Don't know if there is an ideal time interval for checking carb float bowls - the correct answer is "often enough" - whatever that is.
6) Can't stress too much how important monitoring what you find in the fuel and fuel system and filters is - all the time.
7) One point to keep in mind with the header tank drain - it's under the plane where stuff can get splashed up on it and that may then show up as wash off in the fuel sampler - sort of a false indicator.

Really - if a person builds the fuel system to spec and maintains and constantly monitors - there should be little chance of a fuel contam engine stoppage.

Sincerely,

Dave S
KF7 Trigear
912ULS Warp

[Jerrytex]

Should there be some type of header tank drain as well? I thought about using a tee and routing one side to the electric fuel pump and the other straight down to a valve that I could open to drain.

[kitfox2009]

Jerrytex

I have a quick drain directly in the bottom of mine. Every 50 hours or so I completely ALL the tanks. Never found anything yet. I usually take a sample from here every month or so.

Don

[Jerrytex]

Thanks Don.

Did you do yours like what I am talking about? Using a tee? If not, how did you set it up?

I also think I am going to look into getting rid of the glass fuel filter in lieu of a metal one as was mentioned before. I just would want to make sure that it is not a paper element inside.

Jerry

[wildirishtime]

I havent found any metal filters with stainless screens except gascolators.
K&N makes an auto high pressure metal but id rather sump it regular so ill be adding a gascolator w 40micron stainless screen. Thx all!

[Jerrytex]

I think I am going to remove the glass fuel filter that I have under the cowling and order one of these. The element is brass so the swollen paper thing is not going to be an issue. Still have to screw it together but I think I could remedy the possibilty of it coming unscrewed in flight.

http://www.summitracing.com/parts/RUS-645080/


We had a fatal plane crash here in Bryan a couple of days ago. Crashed landed into an apartment complex parking lot. The pilot reported that he was having fuel problems but never made it to the airport. This was a certified plane that licensed mechanics work on so I would think it was maintained properly. I don't want any issues with my homebuilt fuel system.