Fuel filter location

[MrHorsepower]

Hi all,
I have an "if" question. If I mount my fuel filter pre-LP will it be too much of a strain on the piston LP to pull the fuel through the filter? After the LP it would go straight to the injection pump by way of fuel pressure gauge/regulator.
I am running 3/8" ID lines front to back with 5/16" return to the tank.
I would like to do this because I will be running SVO through this and for the purge to shut it off on diesel will go back through the SVO line. I don't want to run a gallon of diesel or so through the post LP filter to get all the veggie oil out.
So veggie and diesel will have 2 fuel filters (one at the tank and one on the driverside frame for diesel and both at the frame and heated for veggie) each from a bus with a 6v92. Very big filters, another concern is the 3/4" inlet/outlets on the filter heads, may cause an air bubble/problem.
Thanks,
Bob

[Ace]

I don't want to run a gallon of diesel or so through the post LP filter to get all the veggie oil out.

Why not? I should think that would be a good idea to prevent plugging the filter in cold weather. As far as the pump location goes, the cannister type spin on filters are meant to be pushed through or post LP. You can maybe get away with it the other way 'round without hurting anything, but it's not optimal, I'm not sure why. Possibly something to do with collapsing the filter media. I ran a can like than on my aux tank for about a year pulling through it with no issues, but it's not recommended. Some filters like the Davcos are designed to be pulled through or pre LP. Are you installing a primary and secondary fuel filtering system? I believe that would be very beneficial for veggie ops.

[Richie O]

On all of my boats I have a primary fuel filter/ water seperator before lift pump and then a secondary filter after the lift pump. I even had some gas boats that had a filter before the diaphram style fuel pump. I have never had a cummins in a boat so I can't say it will work in your case but with my experence I say it should work fine.

[MrHorsepower]

Ace, if I run the diesel through the filter to get all the Veggie oil out then when I switch it to veggie I will have to burn out the Diesel in the filter. Consuming more diesel than I'd like. I ran my filters pre-LP with my 6.2 on veggie with a diaphram pump.
Richie, good point my boat has 4 water seperators inline before the pump, I should be ok.

Plus these filters were pre LP for the 6v92, so it should work out.
Any other opinions?

Bob