Another fuel system overhaul thread...

WMO4IDI

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In parallel to my PoBoy wmo centrifuge project I posted, I've made 2 custom aluminum fuel tanks & I'm redoing the entire fuel system. I was hoping to get some input from more experienced IDI guys.
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What my plan is:

Driver side tank is clean D2, passenger side is WMO & once my flatbed is built I'll hide the existing tank high up between the frame rails & use it as a wmo transfer tank.

So far I've only bought an AC Delco U7000 selector valve which I converted into a U7001 by taking off 3 unglued rubber caps?!? I don't feel like buying an overpriced oem switch, correct me if I'm wrong but I just need a DPDT switch to wire the valve & fuel senders?

For filtration, I was thinking 100 micron stainless mesh filters straight out of the tanks for the big stuff, then fuel filters/water seperators before the fuel selector valve and finally the stock filter/seperator.

Would 30 microns mesh filters be better right out of the tanks? I just want to catch tank crud but not create unnecessary restrictions at the first filter.

Should i just use plain filters before the selector valve?

Or replace stock by plain filter & seperators before the selector valve?

Or filter/seperators everywhere?

Here's a sketch:
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The marine filter/seperators I was thinking of buying:

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I would mount these underneath the sleeper behind the cab & make stone shields to be safe.

For the lines, I'm split between regular flex & hard lines or fancy stainless braided teflon with screw-up-yourself connectors. Does anyone have experience with those 20ft line & 6An connector kits? My only limitation is the AC Delco selector valve which is platic & made for rubber hose so 6An to barb adaptors would be needed there.

Besides that, I'm putting a cartridge heater by the fuel stack inside the wmo tank. Should I also get a heated fuel filter before the selector valve on that side? I have no clue how fast wmo is going to cool down while going through the fuel lines... winters average -20°C around here (-4°F) with the occasional week long -40°C/F. From tank to selector valve is about 4 feet and from the valve to the lift pump another 6-7 feet.

For anyone that's overhauled their fuel delivery system for wmo, is there anything crucial I'm missing or should do differently?
 

Jesus Freak

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I've overhauled my system for majestic NW Florida, it does get cold here but not like Ottawa I'm sure. You'll be cutting your WMO 50/50 with diesel or 80/20 with regular gas at least in your cold season I'm sure, so the pre-fuel selector valve heater is probably unnecessary. I'm thinking that your idea is just enough over-the-top that it's right on.

Oh, and as far as the 30 or 100 micron out of the tank, I wouldn't bother. You got brand new tanks and you'll be centrifuging, so what sludge will there be?
 

WMO4IDI

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Oh, and as far as the 30 or 100 micron out of the tank, I wouldn't bother. You got brand new tanks and you'll be centrifuging, so what sludge will there be?
I was thinking more about dirt getting in the tanks during refills & catching it right there.

Any clue as far as the selector switch? Simple dpdt or its got fancy crossed contacts in there?
 

Jesus Freak

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I was thinking more about dirt getting in the tanks during refills & catching it right there.

Any clue as far as the selector switch? Simple dpdt or its got fancy crossed contacts in there?
I have a manual 3way valve between the seats. And returns plumbed to the WMO tank.
 

Cant Write

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Do you plan to run it through the winter? If so...man I gotta get off my bottom and add another project to my list.
 

WMO4IDI

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Do you plan to run it through the winter? If so...man I gotta get off my bottom and add another project to my list.
Not this winter, I'm tackling major body work & building a flatbed. I'm driving it for now so i can diagnose mechanical issues... not just because it's fun as heck :)
 

94NAIDI

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I live in northern Illinois and I run WMO year round. I start the trucks on diesel and end my drive on diesel. Everything in between is WMO. My formula is 40 gallons of 90/10 mixed with 15 gallons straight diesel. I do centrifuge the WMO and then well mix the other ingredients in afterwards. Mine is obviously a dual tank setup with zero heaters in the truck fuel system. I do run a 30 micron filter post WMO tank pre fuel pump. I run this same formula and truck fuel system setup in a mechanical lift pumped IDI, a Mechanical lift pump Powerstroke, and an electric lift pump Powerstroke. I have had zero issues in the cold with any of the three trucks.
 

WMO4IDI

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What does the 90/10 mean? Filter rating? Sorry to be such a noob.

Or maybe 90% WMO, 10% RUG?
That's what i got from it, 90 wmo 10 rug & then add 15 gals of D2. I'll give it a shot but with our -40s up here it might be a bit thick for January/February.
 

kbenz

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I ran both my returns to my wmo tank at first but if I ran any length of time on diesel I could watch my fuel gauge drop a little too fast for me. I ended up separating them
 

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