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Inline Fuel Filter Options...

Old 01-19-2008, 07:15 PM
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Paul Cataldo
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Default Inline Fuel Filter Options...

I am wondering what brand of in line fuel filters you guys are using? I have never really seen that many options other than the clear one that Sullivan makes (years ago I think it was called the Sullivan "Crap Trap"), here's todays version: http://www.airwildpilotshop.com/more...uct&sku=SUL189

I also used to use a H9 filter that was black? aluminum (I think) and it unscrewed, and had a red plastic frame around a mesh screen, that could be cleaned or changed. I no longer see this at the Airwild site, but I have seen a gold anodized fuel filter somewhere on the net.
The old round, fat Dubro aluminum fuel filters look like complete crap, and I've never used them, shown here: http://www.airwildpilotshop.com/More...product&id=385

There is one new style (thinner DIA) filter from Dubro, that might be better: http://www.airwildpilotshop.com/more...uct&sku=DUB162

The only other in line fuel filter I've seen, that looks like it might be worth buying, is this one from Airwild: http://www.airwildpilotshop.com/more...ct&sku=DYN2006

What other types/brands are out there, and what are you guys using? Is a fuel filter a fuel filter, or are some crap, and some quality? I'm specifically referring to GAS use here, in Desert Aircraft engine applications.
Old 01-19-2008, 08:34 PM
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mikekosatka
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Default RE: Inline Fuel Filter Options...

Paul,
Most people I've seen don't filter the gas between the tank and engine, but rather filter the gas between the fuel can and the airplane. Any good gas filter (automotive) that's clear will do fine. Just make sure your plane's gas tank is clean from the start and you'll be okay. I'm sure you know to empty your plane's tank after flying and that's a good time to filter again, but not really necessary.
Mike
Old 01-19-2008, 09:28 PM
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AirWizard
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Default RE: Inline Fuel Filter Options...

You should filter the clunk because the vent line has a tendency to draw dirt
Old 01-19-2008, 09:52 PM
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Paul Cataldo
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Default RE: Inline Fuel Filter Options...

Well, most (of MANY) of us Giant Scalers prefer to filter the fuel AT LEAST 3 times (yes THREE) before it gets to the engine.
I have a filter in my FUEL jug (clunk filter down in the can), and sometimes an inline is used on the can as well. Then, one clunk filter in my planes fuel tank, and then an inline filter between the tank and the engine. EVEN when all 3 (or 4) of these filters are used, we STILL can find junk/crap in the inline filters after just 25-30 flights.
As for the vent line, NEVER, NEVER, NEVER run a vent line without a Dons' Hobby Shop vent filter attached to the end of the vent tubing. Realizing of course, these filters are a bit big for tiny little fun flyers/etc, but for Giant Scale, they are perfect.
Even when I flew tiny little glow planes as a kid, I would always find a screen, or even use a regular in line filter (with larger mesh) on the vent line, so NO crap would suck up into my fuel tank.
The LAST thing I want in MY fuel tank, is trash and debris from my own shortcomings, which could have been prevented... It's all about a CLEAN fuel system... It's kind of neat to filter your fuel 4 times between the fuel jug and the engine, and STILL be able to unscrew an inline filter and find it all black and dirty....
Old 01-20-2008, 05:29 AM
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pe reivers
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Default RE: Inline Fuel Filter Options...

I was a bit careless with my test stand setup, using only filtering in the supply tank (paper pleat filter). In no time carb problems raised their head and I had to clean the internal carb filter.
In my plane, the carb filter stays clean, because I use one on board filter filter in the fill line, and a felt clunk filter in the fuel pickup.
Two put an additional filter in the fuel pickup line seems overkill, because there is no way any debris can enter that line between tank and carb. (no T-connections)
Old 01-20-2008, 07:33 AM
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rc bugman
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Default RE: Inline Fuel Filter Options...

I am one of those 2 to 3 times filter guys. I filter the gas from the can to the tank and I use one of the filters that look like crap (dubro aluminum) between the tank and engine. I am slowly switching the fleet (25+ airplanes with multiple fuel tanks) to add a clunk felt filter. In spite of the effort, I accumulate junk in both the fuel can filter and the in line filter. All filters receive an annual cleaning. I am thinking of going to an inline auto filter in the pickup line in the fuel can (we use 5 gal fuel cans).

Elson
Old 01-20-2008, 08:50 AM
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pcm
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Default RE: Inline Fuel Filter Options...

I am like most, I filter twice from the can to the plane and one inline filter on the plane.

I use this one. http://www.horizonhobby.com/Products...?ProdID=HAN143

Good luck, pcm
Old 01-20-2008, 12:05 PM
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Default RE: Inline Fuel Filter Options...

They say 'once bitten twice shy'. Filtering my fuel twice before the tank with a felt filter on the fuel jug's pickup and an automotive type paper element filter in my hand crank pump feed line, while using a std. brass clunk and an in line filter to the carb almost cost me a model on a dead stick due to a blocked carb. Simply switching from the brass clunk to a felt filtered clunk and removing the inline filter solved my problems.

Karol
Old 01-20-2008, 12:54 PM
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Paul Cataldo
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Default RE: Inline Fuel Filter Options...

That's right gentlemen! You can't filter that fuel enough! Whoever said "there is no way debris can enter the line between the tank and carb" (when pre-filtering the fuel) is incorrect.
I swear if you have a filter between your tank and carb, it WILL eventually get dirty, regardless of having 2-3 other filters before this point. It just happens.
Old 01-20-2008, 04:50 PM
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pe reivers
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Default RE: Inline Fuel Filter Options...

ORIGINAL: Paul Cataldo

That's right gentlemen! You can't filter that fuel enough! Whoever said "there is no way debris can enter the line between the tank and carb" (when pre-filtering the fuel) is incorrect.
I swear if you have a filter between your tank and carb, it WILL eventually get dirty, regardless of having 2-3 other filters before this point. It just happens.
I said that, and it is true.
If the first filter in the carb supply line does not stop all debris as needed, that filter is no good. In my experience, felt clunk, or sintered filters are good enough. In line filters like a previous poster showed will add nothing, - edit - because the filter strainer mesh inside is quite course - end edit- .

Like bugman Elson said, cleaning the complete fuel supply line after a period of operation is a wise thing to do, because sludge sticking to surfaces on the filter and internal carb parts will reduce flow. Cleaning the filters is a daily chore is ship's fuel systems, which was my profession when young.
Yes, before a season, take out the tank and filters, and wash them in clean fuel without oil. Then you are good for the next season. (don't forget to clean the carb as well)

To repeat my setup:

Paper filter in funnel from jug to fill bottle
felt filter in my fill bottle
paper filter onboard the plane in my fill line
felt clunk filter in fuel pickup to carb
gauze strainer filter inside the carb.

That's 5 filters before the fuel gets to the carb operating parts.
Old 01-20-2008, 05:23 PM
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Paul Cataldo
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Default RE: Inline Fuel Filter Options...

Well here's my setup,

1. Felt clunk filter in the bottom of my fuel jug, tip of fuel line. These are great, and filter out MOST of the debris before it even gets out of the jug.

2. Inline filter on the fuel jug usually just after the pump, and just before fuel gets to the plane.

3. Felt clunk filter inside my planes fuel tank. (same type as inside my fuel jug)

4. Inline fuel filter between plane's tank, and carb.

5. Carb filter that comes inside the Walbro carb.

SOMETIMES I will have ANOTHER inline fuel filter BETWEEN the fuel dot and the fuel tank, in my "FILL LINE", just inside my fuse, behind the fuel dot, but even I consider this slight overkill.

Couple of notes:
a. I have to disagree about the inline fuel filters not working great. Now I can see where the felt clunks probably remove MORE debris, BUT SOME of the inline filters have like a 100micron mesh in them, and that is not too shabby. Some however, don't have such a tiny mesh, and they are indeed worthless.

b. As I said, EVEN when using multiple (4-5) filters such as we do, you can STILL end up finding dirty debris, in the form of "black smudge" inside your inline filters, after xxx number of flights -(H9 makes one that can be unscrewed and cleaned, shown up above in one of my links).



QUESTION: It's been a while since I've done the research, but what are most of you guys with Desert Aircraft, BME, ZDZ, etc engines running for fuel? 87? 89? 93 octane?
I cannot remember what the manufacturers recommend. (been a while since I've flown gas)...
Thanks guys.
Old 01-21-2008, 06:27 AM
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pe reivers
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Default RE: Inline Fuel Filter Options...

b. As I said, EVEN when using multiple (4-5) filters such as we do, you can STILL end up finding dirty debris, in the form of "black smudge" inside your inline filters, after xxx number of flights -(H9 makes one that can be unscrewed and cleaned, shown up above in one of my links).
I use air pressure to pump fuel from the bottle to the plane, so one felt clunk in the fill line will do.
The black sludge is fuel deposit, which will not be stopped by he filters. It is dependent of the fuel quality. In Europe, I think fuel quality is more consistent, and many additives have been added to keep fuel systems clean.

I would not use anything less than leadfree premium grade fuel, 91 octane or better. In the US, pump octane is not the same as the European Research octane. Pump octane is (MON+RON)/2. MON (motor octane number) is about 8 lower than RON (research octane). With low quality fuel the difference will even be up to 10 octane points
All European engines ZDZ, 3W and MVVS prescribe leadfree 95 Research octane (RON), which is 91 PON premium leadfree US fuel. Some people may comment that this higher octane fuel burns slower, but that is academical, and not very important in our low rpm engines. The ignition advance settings have been adapted to these higher octane fuels.
Old 01-21-2008, 07:55 AM
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Default RE: Inline Fuel Filter Options...

My Zenoah manual recommends that I use an 87 premium grade gas but I have my doubts about the quality of the gas available here. Would I hurt anything or cause any damage by using a 90 grade gas. All my engines are equipped with CH or their exl ignition systems.

Karol
Old 01-21-2008, 04:29 PM
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pe reivers
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Default RE: Inline Fuel Filter Options...

When in doubt, select the best gas you can get at regular pumps. These will sell gas for cars. Any engine that has a bit of power, will need gas in excess of 90 PON, so the gas companies will provide it. If they would not, their reputation would go down the drain quickly.
The lowest gas grade available in Holland is 95! leadfree. I guess we are blessed.
Old 01-21-2008, 05:00 PM
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Default RE: Inline Fuel Filter Options...

I'm with the two filter group. One from the fuel stroage medium and one in the tank. Now if you pump fuel from a 55 gallon drum or other large vessel then one more filter would be needed for the bulk fuel. Filters are changes at 100 hours for the plane, and when appearing soiled at the storage container. I've seen black residue on filters when changing them but they are used in a special application and construction tank and it's likely residue from the tank composition. On my personal planes there's some discoloration when hitting between 50 and 100 hours but it's not a big deal since it's filter changing time anyway.

I have to side with Pe on the vent line being a contaminate culprit. It just doesn't happen and even if it did a good clunk filter negates any issues. Really look at an open vent line sometime. You won't see any dirt higher than a inch or so from the open end. If anyone really believes that any dirt can make it up the tube without touching and sticking to the damp sides of the tube, well, I'll say no more there.

People and paranoia seem to be a match made in heaven. When it gets bad enough someone will come up with a fuel line that was designed to be a full length filter that's cut to an appropriate length to fill the distance from the tank to the carb. What troubles me is that it would probably sell and then the questions would fire up over which is better, a clunk or can filter or a full length filter

Next question. Why does everyone worry themselves to death over getting something in a carb that can easily be removed if they clean the screen filter on a regular basis but they have no concerns at all about what enters the carb throat and goes directly into the engine? Worst case is you can land a dead stick plane but you have to replace a bunch of expensive engine parts destroyed by ingesting foreign materials.

If it makes anyone feel any better put as many filters in the fuel system as you can stuff between the gas can, the tank, and the carb. Don't forget to wash your hands and apply a face mask before fueling to avoid any other outside contaminants.
Old 01-21-2008, 07:57 PM
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Bob Pastorello
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Default RE: Inline Fuel Filter Options...

And *I* was hesitating to reply with my comment about never changing the klunk or line in my weedeater/chainsaw/blower appliances......

(This from a guy with a jug filter and the fill line filter and the ceramic filter klunk)

Now, (thank you Pat), I'm freakin' out over the impending disastrous ingestion of my cowled rear-intake gasser carb....OMG, ***WHAT*** do I do now???????????

Old 01-21-2008, 11:30 PM
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Default RE: Inline Fuel Filter Options...

I like to use a clunk like a chainsaw tank has. It is said to filter real good and pick up about 100% of the fuel. The only other thing I do is filter the gas mix through a colman fuel funnel and into fuel container with pump attached. Best Regards Capt,n
Old 01-22-2008, 07:14 AM
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Default RE: Inline Fuel Filter Options...


ORIGINAL: Bob Pastorello

And *I* was hesitating to reply with my comment about never changing the klunk or line in my weedeater/chainsaw/blower appliances......

(This from a guy with a jug filter and the fill line filter and the ceramic filter klunk)

Now, (thank you Pat), I'm freakin' out over the impending disastrous ingestion of my cowled rear-intake gasser carb....OMG, ***WHAT*** do I do now???????????

At one time I used a Ryobi ceramic sintered filter. It filtered very well, until the engine started cutting out. Solving that problem drove me nuts, until I exchanged the ceramic clunk for a felt clunk. Problem solved.
The area that can catch the minute debris particles in a sintered clunk is much smaller than in a felt clunk. Both have the same excellent capacity to empty the tank to the last drop and prevent air bubbles in a foaming tank.
I like the felt clunk therefore better. Come cleaning time, I can wash the felt, knead it until clean and fit it again. With the ceramic filter, all you can do is replace the unit, because it is very hard to get at the debris particles stuck deep down in the sintered body.
Old 01-22-2008, 10:42 AM
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Tired Old Man
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Default RE: Inline Fuel Filter Options...

It can be as simple a filtration system as one can make as long as it's effective. If you can filter twice, each time to about 20 microns, there really isn't much left that can cause a problem in a single season of flying. For most that could likely be extended out to a couple of seasons but an annual check of the condition of the fuel system should never be bypassed. If you can keep crud out of the tank, the tank filter can keep crud out of the carb.

At least for me the advantage of using a two filter system with one in the can and one in the tank is that it eliminates the break in the fuel lines for a third filter. That's one place gone that can't be a leak factor. There's no disadvantage to using a third filter for those that choose to do so, but it does add complexity, cost, and another location to worry about.

The turbine guys are another story. They have to be anal about their fuel systems.
Old 01-22-2008, 05:27 PM
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pe reivers
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Default RE: Inline Fuel Filter Options...

If you clean the system at regular intervals you are quite right. Even just the tank felt clunk as single filter would be sufficient then. BUT, if you do not keep your system that well, more filtering is required in order to keep the one most important, the suction line filter, from clogging.
Wiping the fill line clean, leaves lint particles on the fill line end which subsequently enter the tank on the next fill-up. Storing your stuff in a work shop with balsa dust inevitably gets dust into the fuel fill system. That's Murphy's paradise for sure.
Nothing to be anal about, as long as the internal carb filter stays clean. If it does not, its a wake-up call or a rap on the knuckle to pay heed better.
Old 01-22-2008, 07:06 PM
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fiery
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Default RE: Inline Fuel Filter Options...

1. Filter on the end of the fuel jug pick up line (bell mouth style as sold by Du-Bro)

2. Filter in the fuel filler line - jug to 'plane

3. Felt clunk (as sold by chain saw and weedie shops) in tank

4. Filter in the fuel feed line - tank to carb. No "T"'s ... I use a 3-line tank set up.

I use small clear plastic filters sold by my friendly local motor cycle and scooter dealer for applications 2. and 4. above. I ask for the smallest diameter filter they stock, typically installed as service replacements in 50 cc scooters (getting the picture here gents?).

They are small, withstand heat, have incredibly fine gauze, and cost less or little more than the horrifically marked up prices for items more suited for glow fuel .60 size engines (crap traps and the like). I have to soften the tygon tubing with hot water and apply a little liquid soap to get the lines to fit, but once on ... they stay on without clamps!

Highly recommended. I won't go back to glow-style in-line filters. Works for me.

No rubbish in the walbro internal filter any more ...




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