Rembrant Posted April 4, 2023 Share Posted April 4, 2023 Guys, I'm running a little electric fuel pump to supply my 4bbl Summit carb. The pump is linked below: https://www.holley.com/products/fuel_systems/fuel_pumps_regulators_and_filters/fuel_pumps/carbureted_fuel_pumps/carbureted_electric_fuel_pumps/parts/12-426 I went looking to buy a replacement inlet filter so I had a spare for the one that came with the pump. According to Holley it is an FEP-735, which according to the link below is 74 micron. https://aftermark.net/fep735-facet-in-line-filter-for-posi-flo-cube-fuel-pumps/ I went to my local CarQuest auto parts store, and they do not have a direct crossover to this FEP735 filter, but they have the exact same filter in 20 micron....not sure of that is correct, because I could almost see through the mesh in it... It got me thinking... What micron should* the filters be...for both pump inlet and carburetor inlet? My carb filter...I thought was 40 micron, but after checking this morning I think it is only 20, according to the auto parts store. Link to comment Share on other sites More sharing options...
Gary Lewis Posted April 4, 2023 Share Posted April 4, 2023 A 74 micron filter is very coarse. I looked up the filter for Big Blue, which is a Motorcraft FG872. I can't find a statement in that listing, but I did find one for another filter that says "Motorcraft Fuel Filters capture 98 percent of particles 8 microns or larger, ensuring a steady flow of clean fuel to your vehicle's engine for top performance." So I think a 20 micron filter is a lot closer to what you want than a 74. Link to comment Share on other sites More sharing options...
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