100 micron pre pump fuel filter, 75 front pump location Options

[rfinegan]

I am looking to route my fuel lines one more time (no kinks). While in there I will change my line to AN fittings and braided fuel lines. Does any one have a recommendation for a Pre fuel filter of 100 microns? I have a good post hi pressure filter in place already

Something like this?
https://www.summitracing.com/parts/sum-2301...OlOTtQ0t6Qf48Fc

[jim_hoyland]

As to “ NO pre pump filter aside from the tank screen” I have wondered why this is a good idea. Suppose that screen get clogged up: And your out on an open road ?

[JamesM]

As to “ NO pre pump filter aside from the tank screen” I have wondered why this is a good idea. Suppose that screen get clogged up: And your out on an open road ?

No screen at all is also an acceptable (and possibly preferable) option. This is how it was done on Vanagons.

You want the least amount of restriction pre pump. Shortest, fatest, straightest suction lines possible with no filters restricting flow. Vacuum on the inlet side of the pump can cavitate the fuel which leads to a noisier fuel pump as well as potentially causing damage/shorter life to the pump. Depending on the condition and routing of the fuel lines it can also cause the feed line to collapse on itself causing fuel starvation.

Injectors require filtered fuel for long life the pump doesn't, it needs unrestricted fuel flow.

[Superhawk996]

As to “ NO pre pump filter aside from the tank screen” I have wondered why this is a good idea. Suppose that screen get clogged up: And your out on an open road ?

No screen at all is also an acceptable (and possibly preferable) option. This is how it was done on Vanagons.

Injectors require filtered fuel for long life the pump doesn't . . .

Maybe . . .

If you’re going to delete all pre-filtration you better know what type of fuel pump you’re using (turbine, gearotor, or rollervane, diaphragm or vibrating plunger like a Facet).

Turbine pumps are not forgiving if run without pre-filtration.

A 100 micron pre-filter doesn’t cause any significant restriction to the pump inlet nor does the OEM sock.

[JamesM]

As to “ NO pre pump filter aside from the tank screen” I have wondered why this is a good idea. Suppose that screen get clogged up: And your out on an open road ?

No screen at all is also an acceptable (and possibly preferable) option. This is how it was done on Vanagons.

Injectors require filtered fuel for long life the pump doesn't . . .

Maybe . . .

If you’re going to delete all pre-filtration you better know what type of fuel pump you’re using (turbine, gearotor, or rollervane, diaphragm or vibrating plunger like a Facet).

Turbine pumps are not forgiving if run without pre-filtration.

A 100 micron pre-filter doesn’t cause any significant restriction to the pump inlet nor does the OEM sock.

Yeah that is a good point of clarification, this depends entirely on the pump you are using.

The configuration I put in all EFI cars now uses the 75 style 2 port pump, no pre filter, good post filter and I feel pretty safe about it. Why? Because that is the exact layout Volkswagen finally landed on with this exact pump after running it on production cars for 10 years.

The Vanagon fuel system is basically the continued evolution of the 914 setup and they continued to make incremental improvements to it up though 1987. They started out almost identical to the 75 914s with a front mounted fuel tank, into a 8mm to 12mm pre pump filter/adaptor, into the 2 port pump and no post pump filter. This then changed from moving the pre pump filter to a post pump filter, and then changed again in the last few years to running a 12mm port on the tank directly to the pump. Pretty clear they were progressively trying to increase the fuel available to the pump inlet side and the service bulletins even stated this was done to reduce cavitation, noise, and extend pump life.

Seen it fairly often, even just undesirable routing on the inlet hose to the 2 port pump on a 914 will make the pump louder than hell.

Only downside I have encountered from this no pre filter setup so far is now the pumps are so quite its a lot harder to tell when they are running or not.