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Does it matter if the filter is before the fuel pump (Mechanical). It seemed to work fine on my test stand but I don't know how well it would work in the car.

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6426yy said:
Does it matter if the filter is before the fuel pump (Mechanical).
IMO- the closer to the carb the filter is, the better.

Junk coming from the tank won't hurt the mechanical pump, but the pump itself might generate junk that you don't want getting into the carb. If you have an in-carb filter like a Q-Jet, for instance, you can put the inline filter before or after.
 

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Junk coming from the tank won't hurt the mechanical pump, but the pump itself might generate junk that you don't want getting into the carb.
?????????????? How does a Fuel Pump generate any Crap,..???????

Put the filter Before the fuel pump,...
The valving in the fuel pump don't like Crap in them Either....
 

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From the factory many cars came with large surface area filters upstream of the fuel pump (example=1965 Mustang). My 65 must has original carb which never had an issue with pump trash in the carb. When I rebuilt the original carb there was a "plaque" restricting the jets but no particles. This filter seems to last forever.

From the factory many cars came with a small surface area filters downstream of the pump (example=1966 305 V6 GMC). My 66 GMC also has original carb which has never been rebuilt and happily chugs along at 6 to 12 MPG.

My 67 mustang came with a in-line filter down stream of the pump and nearly left me stranded when it started to plug.

The small in-line filter is prone to plugging where as the large canister is not.

Fuel tanks come with a fuel sock to catch larger particles in the tank.

I think the optimum setup is to install a large surface area low pressure drop filter down stream of the tank and a low pressure drop in-line filter down stream of the pump. You won't loose much flow if your filters have a low pressure drop (dP).

If you are sure your tank is hospital clean and has a functioning sock then you can install only one in-line filter down stream of the pump. It is possible for debree to get stuck in pump check valves and cause malfunction.

Conversely, if you are not sure your tank is hospital clean with a functioning sock then you should install a large low dP filter down stream of the tank.
 

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How are all you guys getting 'JUNK' in your tank? Where do you buy your fuel, at the pick a part fuel depot! Most 'good' service stations have a filter on their delivery hose to remove any debris before it gets to your tank. If your filling up your tank from old jerry cans and pails, your bound to get junk in the tank. Most seals and diaphragms are made from fuel resistant neoprene and will not harm your fuel system, UNLESS you do something stupid, like put methanol in with your fuel.

A nice way to keep your fuel clean is putting a large fuel filter before the pump and close to the tank as possible. If you use a spin-on type, it makes changing very easy. A steel in line filter before the carb will gather any debris in case something let loose within the fuel system, i.e. shavings or filings from a fuel line repair.

The sock that is in your fuel pickup in your tank will keep out rust sludge, debris, and some of the water that is in your tank, but its not a miracle worker.
 

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alittle1 said:
How are all you guys getting 'JUNK' in your tank?
It doesn't much matter how, the fact is, "junk" does enter the fuel system. With cars as old as many hot rods are, there's no way the tank's gonna stay perfectly clean. If not from a deteriorating tank, then from the lines, fittings, repair work, etc. that will eventually introduce "junk" into the fuel system- it is not a closed system, after all.

Most 'good' service stations have a filter on their delivery hose to remove any debris before it gets to your tank.
You are assuming that the franchise's proprietor is changing out those $10-$20-a-pop filters as per the recommended schedule. Good luck w/that! If they're even installed in the first place.

you do something stupid, like put methanol in with your fuel.
Methanol 10% is de facto in FL and GA as well as other areas- there's not much in the way of choice. The gas stations are allowed to do this- and none in my area say they don't- so the assumption can be made that they do. With this alky comes water, as well. If this sits long enough, the alky evaps and the water is left behind.

But even if not, the tank, lines, pump, carb and rubber will deteriorate w/time, regardless.
 

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I like to put the fram hpg-1 canister filter before the pump, and then a small filter in line from the pump to carb. Just stay away from the cheapie plastic or glass filters in the line from the pump to carb, the heat is too great and one of my customers lost his falcon wagon to fire from the glass filter overheating and breaking thus causing a fire! :pain: I see poeple everyday that have the plastic filters with great expanses of rubber hose under hood with the filter strapped or zip tied to the front of the engine-YIKES!! :pain: Safety first!!
 

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alittle1 said:
How are all you guys getting 'JUNK' in your tank?
Thats the problem with ethanol being added to gasoline is that it harms the equipment. Rust in steel tanks causes scale to get sucked into the fuel pump. I would rather deal with two filters and be save than one and get stuck or worse.
 

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streetrodderbn said:
I see poeple everyday that have the plastic filters with great expanses of rubber hose under hood with the filter strapped or zip tied to the front of the engine-YIKES!! :pain: Safety first!!
They wouldn't even be allowed to race at an NHRA or IHRA sanctioned event. One quick way to see past the BS if they are telling you how they trophied at this or that event.
 

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The trash in gas starts at the well head then the refinery then the trucks that transports the trash and then the gas stations that house it and dispenses it to us. Nothing in this world is trash free and that's especially true with fuel. Anyone here ever work in a refinery? Anyone ever do a storage tank turnaround? Tank farms are made of steel and are not lined.....can we say major rust issues after several years of use. Anyone who thinks your fuel from the hose at the gas station is clean is only fooling themselves. Run a GOOD filter system on your rod. Yes, the refiners use filter systems but they are not designed to catch the really little bity tiny weenie stuff lol
 

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Yes there is junk in the trunk!

alittle1 said:
How are all you guys getting 'JUNK' in your tank? Where do you buy your fuel, at the pick a part fuel depot!
I have seen several small surface area fuel filters plugged with trash.

It is not uncommon for an old classic car tank to contain some junk that can indeed pass the fuel tank sock.

Good luck buying alcohol free fuel in every state.
 
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