2 tank system on an IDI using FPH's with the stock valve system for WMO?

I've been mixing mixing WMO at about 50/50 in my 1992 Ford F350 IDI truck for a long time. It's always ran great and I'm thinking it's time to go to the "next" level. My truck is basically an all stock 2 tank system. So my thought is to use the back tank for basically 100% WMO or something very close to that and the front tank for a lighter mix of say 50/50.

I've collected a few parts and have two FPH's (flat plate heater). I think one is an 18 plate and the other is a 30 plate. I've also got 50 feet of 3/4 heater hose. I've also got 3 fuel filter bases if needed

My thought is to fabricate a copper coil (maybe 1/2" tubing) to go in the tank surrounding the fuel pickup tube, then install the 30 plate FPH in the fuel line near the tank. I would use the 18 plate near the injection pump. Basically I would be using the stock fuel lines, filter and switching system/valves. The "oil" tank would be heated by an internal coil and then by the larger FPH. The smaller FPH would heat the fuel from both tanks. I could also run the heater hose down the frame rail right on the fuel lines.

One concern I have is the factory mechanical lift pump. I wonder if it could handle the WMO even when heated. Would the heated WMO be too hot for it and will it be able to pump the higher viscosity WMO? If not then I need to consider some type of electric pump. I can't handle the expense of and Airdog or Fass pump.

Another concern would be the factory switching valves. Will they handle the WMO and temps? I really can't afford to buy hydraulic valves right now so that might be a deal breaker if the factory unit won't hold up for a while.

My last concern would be the smaller FPH heating the "lighter mix". I wonder if there will be any ill effects of heating the lighter mix? I don't think there will be but maybe someone can ease my worries? This smaller (FPH) heater will heat the fuel from both tanks all the time.

I should add that I'm cleaning all my WMO using a centrifuge system I threw together. It's basically a small WVO oil centrifuge I bought from ebay mounted on top of a 55gal barrel. I added a hot water heating element and recirculate the WMO through it for 8-12 hours. It works great and I have no worries about the oil itself.

I'd really appreciate everyone's thoughts...

Thanks
Greg

For the switching valves get manual ball valves and mount them next to the seat. Search "manual tank selector valves" good thread on it.
I would get an electric pump. Get a quality one. Search "carrier pump group buy."
It would be recommended to add another filter into you clean oil tank on the outlet.
Run diesel only in one tank (no heater needed in there), then you can actually be able to start it in the mornings.
With the Ball valve setup: start it on diesel, then once up to temp, switch both valves to WMO. On your return trip, switch your feed ball valve to diesel a few miles from home, and the return feed valve a mile or so after. That'll keep you from getting a lot of WMO in your diesel tank.
(May not be a big problem anyways, but still)

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I have run pure WMO, and even pure gear oil in a COMPLETELY stock fuel system on my 1990 IDI. No heaters of any kind. Pump and filter will move the oil just fine at temps above 50F 40 to 30 gets iffy on pure wmo as far as getting it through the filter. Anything below 30 and I see fuel starving at high rpm or heavy throttle.

Thanks for the replies fellas...
I had read both of the threads that 79jasper mentions. The ball valve thread is definitely simplicity at it's best. But honestly I don't think I will go that route. I'd like something a little more "elegant" I think even if I have to wait a while to save money to do it. And in saying that I mean no disrespect to that system. I had looked at the carrier pump thread also. One of the boat places has them for less than a hundred bucks. If I go that route I think I'd install it just ahead of the valves instead of in the engine compartment.

Josh, I too have run 100% wmo in the summer as a little test and had good results. Here in Kentucky we see temps down to the teens for several days at a time and occasionally we will drop down to the zero range at times. I think I definitely have to heat the oil. My best course I think right now is install the heaters and do a little test run. If the stock pump won't handle it I can always just run a lighter mix till I can afford an electric pump.

We always talk about cross-contamination in fuel system. My thoughts are that the small amount of oil that may end up in the lighter tank or the amount of lighter mix that may end up in the oil tank are minimal and won't make much difference to me. When I mention lighter mix even that will have at least 50% WMO in it. I've ran that year around with no heat and no problems.

One last thought....I wonder if it's possible to "pump through" the factory lift pump. In other words I wonder about installing an electric pump at the WMO tank as a sort of booster pump for that tank only. I think without a doubt this would need to be one of the low pressure pumps. It may not even be needed.

Thanks
Greg

If you do go with a electric "lift" pump I would try to keep the wmo mix rate not more than 80/20.
I use a carrier pump electric pump, others that have run wmo & e- pumps had problems with higher percentages.
I'm in the process of over hauling my engine so not using wmo now, but thats my mix rate, maybe a little stronger during warmer times.
With your setup on the pickup, definitely have a 3 port valve on the return side. This keeps the start up diesel clean, very important in cooler temps.
Don't have access to my drawing of my 3 tank system, 2 stock 1 wmo tank, I'll try to remember, just for info

Don't pump through the mechanical lift pump. You can add it in parallel, but better to just go with one or the other.

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I've ran 90/10 with an electric lift pump. Don't buy one of the little green mr.gasket ones. They don't move oil. But a Holley or mr. Gasket 95p pump. I've had great success with the mr gasket one.


I ran about 20k miles of oil through the factory switching valve before it left me (1986 original) and replaced it with a NOS ford one.

My other 86 I put ball valves on it and I'm not all that impressed you have to switch both then wire in toggle switch to switch sending units. Then if you don't drive the truck for a month you'll forget what way the valve goes to witch tank haha

Also keep in mind fuel is was cools your injection pump so I'd try to keep your fuel into it around 120-140. If your pumping in 180-200* fuel then it won't cool a thing.

Frank that's a good point about IPs & cool fuel, Mel(agnem) would be able to talk about that.
He's got my turbo now, I'll try to remember to ask him about that.

I run stock lift pump on two tanks, one diesel, one WMO thinned with RUG. Start on diesel and switch to WMO immediately without issue. Switch back to diesel a couple miles out from destination.

Cross "contamination" is fairly minimal, only saw a slight color change in the diesel tank (filled thru sender).

It's been fine in cooler temps, no flow issues for me. I have thought about running a 12v 200w filter heater to see if I could cold-start on WMO.

Keep in mind that a heat exchanger will take some time to have any effect, an electric source for initial heat may be required to minimize runtime on the light mix.

I don't know how cold it gets in Abileen, but I regret leaving my truck on oil every single time it's below 60F. I have had to pull start the truck on numerous occasions because I left it on oil.

Ok how about this.
Made this drawing with 2 stock fuel tanks with a extra 3 port valve on the return side of the fuel system.
I think with this valve a person could stay with 2 tanks and keep the wmo fuel from getting to the clean diesel.
I think??? Let me know if this doesn't work, I'll keep looking also.
With this setup, the front tank would have to be the wmo tank.

That would work fine with either tank, just plumb it to the tank you specify as oil. The problem being a forgetful absent mended aspie like me will forget, and promptly dump a full tanks worth of fuel out on the ground. Takes about 15 to 20 minutes of running down the highway to dump a full tank out the filler neck. Well.... at least it does on a fuel injected gas burner when the tank switching valve fails to switch the return. Found out how gimmicky the OEM fuel switching valves are on the dual tank gassies.

IF I ever fool around with separate returns etc etc, I REALLY like the idea of having a shutdown delay. I have several adjustable timers, delays, and other automation controls left in my toolbox from the plant that closed down. My idea is to automate the shutdown process. Whenever the key is switched off as another button is pressed momentarily, it will trip a 5 minute delay that will automatically switch the draw to the D2 tank, and the return to the dirty tank. While that five minute delay is active, the FSS solenoid will be powered through the delay controls. That will allow a clean purge, and bypassed return, that automatically resets to "switched" settings upon start up. I also like the idea instead of having a button to trigger it, having it set by pressing the parking brake.

I use the gear as my parking brake, but that wouldn't work, so for me the best option would be to tie it into the parking brake. SO if I plan to kill it as normal I turn the key off and throw it in gear. If I'm shutting down for the day night etc. set the brake, turn the key off and allow the delay to do it's thing. I can then adjust the timer to the optimum time to purge, since it can vary wildly if doing it while driving.

Good points Josh about fuel "transferring" between tanks when purging.
When I finally got my routine of start up on regular diesel, using wmo during the trip, then close to my destination switching back to D2, I was surprised how much D2 used or mixed into the wmo tank.
But thats part of using wmo and wanting to purge fuel.
The timers and delays looks really interesting, I hope that kind of setup would be reliable.

Well, I was talking about a time that I had a FSV fail, I was on a long trip, pulled into a fuel stop, filled both tanks and took off. 20 minutes later I ran out of fuel, thought something was mechanically wrong til I started investigating and found one tank literally running out the filler neck onto the ground, and the other tank really was empty. I drove the truck for another year with a bad fsv, it always returned about 80 percent of the return fuel into the front tank no matter the FSV selection. From then on out I always had to empty the front tank first and then switch back and forth from the back tank til I managed to suck all the fuel out of both tanks. The death of that truck is what drove me to the diesel world. When the tranny went down in that truck I decided I was no longer spending 150bucks a fill up only to do it again 10 to 15 days later. Bought my old IDI and haven't looked back to the gasser world. I will admit, it was nice to hop in the truck on a low teens and high single digit days and simply turn the key and drive off.