Originally Posted by genscripter
How true that is. After you drive home on a backup fuel for the first time, you'll wish all cars have a backup plan.
Now for my 1.5 cents. I have a 7.3 idi and have been running some very nasty wvo that looks like coffee mixed with grits for 4 years now at a rate of 30-40 gallons a week. The texture is of course solid fats from the chicken wing skins that were fried in it. I filter and burn it all. Solid fats and oil alike. In the winter I have to bring it into the basement ahead of time and let it warm up before it will flow through the window screen i use to catch the big chunks of food as my first step other wise it will just set on the screen, its that thick.
I do not have a heated fuel pickup. I used a 3/4 cpvc pipe up to the top of the tank where it goes into my heated fuel line. Its large and hard to clog. I have run it in temp of single digits with no problems. In the winter I mix 10% diesel into it to cut the fats so it will flow. From there it goes to my factory fuel pump that I run diesel and wvo through. This is the biggest weak spot in my system and because of that I put a new one on every year for safety. I had been planning to go with separate electric pumps but have never gotten around to it. From the pump I seperated the lines back out into two systems again. Wvo goes through 36 plate heat exhanger from ebay and then though a seperate filter. From there it ties into the steel line going to injector pump. The way I use cutoff valves to isolate the fuel pump from the separate systems means I do not have to use check valves.
Return lines is where if differ the most.
I have another valve that switches back and forth from the diesel to the wvo return lines at the back of the motor. I do not worry about the contamination of wvo into my diesel. Its such a small amount of contamination in the return lines that it has never been a problem. I do not have timed switches mine switch at the same time. I usually burn about 10 gallons of diesel a week switching and it has never been enough to bother my truck.
I also elected to run a separate return line all the way back to my wvo tank. This is important for people with an idi motor. Air intrusion is a constant battle with these engines that most people do not have to deal with. From return lines orings that will need replacing even more often because of the oil. Even the caps themselves will get hard and brittle from the oil and heat. I installed a seperate 50 gal wvo tank that doesn't have a fuel gauge so when I run completely out of fuel the lines are full of air, or turn real sharp on a low tank. Its a lot easier to pump air into the tank than to pump it through your injectors. This is also another reason for an electric pump on these trucks.
Most important things in my opinion:
Heat the fuel to 160 min. The thermostat in your truck is 185deg so if your truck isn't completely warm its not hot enough.
Start and stop on diesel. Make sure your system is clean from wvo before you stop. I drive the last 1-2 miles on diesel before I stop.
If your not using your system every day then you need a separate aluminum tank and aluminum lines. Polymerization is of the most concern in systems that are not used daily. My tank is steel and my fuel line is copper but the oil does not sit there long enough to polymerize. It is the oil that polymerizes, not the metal and it takes a little time to change. Mine is fresh every week so its not a problem for me.
Being over cautious and building a better system in your truck or filtering set up will not hurt you. But trashing your motor will cost you more than a few cheap trips on oil is worth.
Filter your oil. then filter it again. then filter it again.
I let my oil settle for 6-8 weeks
Then I pour the best off the top and run it though a series of sock filters.
I then send it through a cold up flow system.
Then a golden rod filter.
Now its ready for my truck and the filter on it