Water/fuel separator

[Tim7139]

Just curious, anybody have one installed on your fuel system, given the potential issues often found with today's pump gas?

[bobcowan]

Do you need one on any of your other vehicles? Not an issue; don't worry about it.

[Ron61]

I don't. If something is going to set for a long period like my lawn equipment I just add some StaBil to the gas.

Ron

[Tim7139]

Well maybe. I asked because even though it's uncommon, my car came with a Mercury unit located in an unobtrusive spot. I''ve swapped out a couple filters and although nothing scary, I found crap, I'd just assume not push through my engine. They do not appear very common , it seems.

[DanEC]

I think I would want to do some research on it and see how much flow it's rated for and at what pressures - to make certain it's not leaning your carburetor out on acceleration. If it passes enough fuel and it's there - could be a good thing.

[Tim7139]

Originally Posted by DanEC

I think I would want to do some research on it and see how much flow it's rated for and at what pressures - to make certain it's not leaning your carburetor out on acceleration. If it passes enough fuel and it's there - could be a good thing.

Fuel pressure guage between it and carb.

[bobcowan]

Originally Posted by Tim7139

Well maybe. I asked because even though it's uncommon, my car came with a Mercury unit located in an unobtrusive spot. I''ve swapped out a couple filters and although nothing scary, I found crap, I'd just assume not push through my engine. They do not appear very common , it seems.

Crap? or water? If you're finding a lot of water, you need to ask where it's coming from.

If it's general schmutze, then you need a good filter. But I think every fuel system needs a good filter or two.

[Tim7139]

Originally Posted by bobcowan

Crap? or water? If you're finding a lot of water, you need to ask where it's coming from.

If it's general schmutze, then you need a good filter. But I think every fuel system needs a good filter or two.

Well, the water falls from the sky. Then it soaks into the ground, which occaisionaly leaches into the fuel tanks somewhere between Saudi Arabia and my station, contaminating the fuel we all pump into our cars........more or less.
I used to think a guy broke into my garage with a watering can but the deer cameras I put up yeilded nothing.

[Gaz64]

The water is also in the air.

Condenses in the tank from pressure/temperature change etc.

[Tim7139]

Rarely, except for longer term storage type issues. Truth be told, most of it gets in the fuel from compromised storage tanks, along its path to your car.

[Mastiff107]

Ethanol does absorb water from the air. I've never had a separator on a car but I do have one on my boat. With a 30 gallon tank and the boat sitting on the water over the winter I would get about 8 oz of water in the separator when I used ethanol blend gas. I was surprised how much ethanol actually soaks up. I switched to marine gas (ethanol free) and no longer get any water in the separator.

[RallySnake]

Fuel/water separators are necessary on diesel systems. They get a lot water in the tank and it sinks to the bottom. On 18 wheeler truck's and railroad locomotives, they periodically have to drain the water from the bottom of the fuel tanks because there's no room left for the fuel.

They are not necessary on car's gasoline systems because the water stays mixed with the fuel and the engine can burn the water. They even make water injection systems for more power.

I have given up on aftermarket fuel filters. They are too small. I buy the largest stock type filter I can find in the auto parts store (with 3/8th inch in and out tubes) and mount it before the electric fuel pumps (I always have two). I have had 6 or 7 electric pumps fail over the years before I did this and am tired of buying them. I use another fuel filter between the pumps and the carburetor. I take my fuel tank out of the car about every 10 years and use a garden hose to wash it out. It is amazing how much sand and rust comes out. You would think that branded filling station fuel (I usually use Shell) would be pretty clean, but it's not.

[Tim7139]

Originally Posted by RallySnake

Fuel/water separators are necessary on diesel systems. They get a lot water in the tank and it sinks to the bottom. On 18 wheeler truck's and railroad locomotives, they periodically have to drain the water from the bottom of the fuel tanks because there's no room left for the fuel.

They are not necessary on car's gasoline systems because the water stays mixed with the fuel and the engine can burn the water. They even make water injection systems for more power.

I have given up on aftermarket fuel filters. They are too small. I buy the largest stock type filter I can find in the auto parts store (with 3/8th inch in and out tubes) and mount it before the electric fuel pumps (I always have two). I have had 6 or 7 electric pumps fail over the years before I did this and am tired of buying them. I use another fuel filter between the pumps and the carburetor. I take my fuel tank out of the car about every 10 years and use a garden hose to wash it out. It is amazing how much sand and rust comes out. You would think that branded filling station fuel (I usually use Shell) would be pretty clean, but it's not.

In that case I would guess the separator could be considered a great overall filter.
I guess another issue seems to be that water contamination seems to be a regional issue. Up in the north east there's lots of aging infrastructure and still seeping storage tanks, which is why my rig had one installed when built.