Mountaineer

Hey Guys, at what point does the the stock fuel filter become a restriction(Granted the filter is new and clean)? I'm guessing that it's has it's limitations .

Basically at what point does the outlet pressure stop rising as inlet pressure is increased.

airman

I see you are running Biodiesel or oil I had to bypass my stock filter because it would not flow fast enough to keep up with my setup. It seems that b100 swells paper filters very quick and slows down the flow rate I am running a spiro spun filter or a cotton filter and have been for well over a year now they work and last longer.

badme

I can only get 3000 miles on mine. Then it gets plugged and the fuel pressure starts to drop

Mountaineer

Yea, Thanks guys, but I'm referring to diesel fuel and at what point does it come a restriction if ever ? Is the filter capable of flowing more fuel than a vp can handle?

bent valves

The 10-micron filter in the stock filter housing will drop about 4 PSI with a flow rate of 45 GPH. The lift pump pressure does not change the pressure drop across the filter assembly but with too low of a pressure, you may not be able to flow 45 GPH. So as you raise the lift pump pressure, the fuel filter outlet pressure will continue to rise. At some point the filter will max out and increasing lift pump pressure will not make a corresponding increase in the filter’s output flow, but it will always flow more with a higher pressure lift pump. I will guess that the stock filter reaches its limit at about 60 GPH flow and at a much lower flow rate and more pressure drop with a dirty filter.

kawi600

I did a veggie conversion on mine and I chased down a problem where the pressure would dip down to 12 at WOT. Looks like it was a combination of a few things. The valves I used were restrictive, so I bought a larger feed valve. I changed the fittings at the IP inlet with some loot from Vulcan (to get rid of the banjo fittings) and lastly I gutted the OEM filter assembly in place of a nice 90GPH Racor that I stuffed under the bed. Also gives me the ability to run a lower micron rating with a larger filter to keep the flow rate.