Captain Rawles:
Let me add a caveat to burning raw oil (Filtered Vegetable Oil, Waste Vegetable Oil, Straight Vegetable Oil, Raw Vegetable Oil) in diesels.
I have heard claims stating; “These engines will burn anything! You can dump in cooking oil, heating oil, kerosene, bacon fat, filter your used crankcase oil through a nylon stocking…you can even burn perfume!” To that I must add; “Garbage in, garbage out”, only not all the garbage goes out… it settles in your engine.
All myths are based on some truth, and those claims are no exception.
First, stay away from animal fats. They clump. They also stay suspended. They just won’t filter out. They are a nuisance. Waste Vegetable oil can be filtered, or refined. Fryer oil that has cooked french fries is fine, but when that same oil has been used to deep fry fish, chicken, or worse yet, pork, it is difficult to avoid problems, and those problems will always occur at the worst possible time. Each new load of vegetable oil (V.O.) should be tested for acidity, then even if you plan to burn S.V.O., make a small (quart) batch of biodiesel to test for clumping, or soap. If S.V.O. is to be burned, well, then just roll the dice and hope for the best. Yes, it will work in your diesel, but I guarantee that someday it will fail, and you will miss that job interview, or be stuck in a blizzard. Your diesel will not suddenly stop on a nice Summer day while just sitting in your driveway. Just won’t happen…. Second, Vegetable oil, and to a lesser extent, biodiesel will cause coking, which is a fouling inside your cylinders, especially around the valves, pre-chambers, and injector nozzles. Fouled nozzles can make a diesel difficult, or impossible to start, and the colder the weather, the more this condition is exacerbated. Also, fuel filters must be replaced on a more frequent rotation, and the use of an engine oil bypass filter is just plain ol’ common sense. More ash means dirtier oil, and more wear. An off-the-shelf oil filter will remove particles down to 40 to 75 microns. The problem is that engine damage also occurs with sub-20 micron particles. Get a bypass filter, and install it right away. The use of V.O. means you will generate more ash, and more ash means more engine wear, and more engine wear means a greater risk of an inconvenient engine failure.
The main culprit is glycerin and no, more heat added to the fuel won’t solve the problem. Glycerin is a problem that won’t go away, and if an owner is set on burning V.O., or biodiesel, then the injector nozzles must be cleaned, or replaced on a set schedule (every three months, or even more frequent is not unreasonable), and the pre-chambers reamed of carbon to prevent glow plug failure. Biodiesel must be washed, and then precipitated for at least seven days before use. Remember… that glycerin has to go! As for other fuels, yes, you can burn up to 50% kerosene with your diesel, and while this works well in extreme Northern Winters, the price of kerosene makes such a practice very restrictive. Gasoline (up to 10% has been successfully used in cold weather, but that is really just a time bomb. Your (expensive) diesel engine could grenade today, or in several years, but adding gasoline to diesel is not the wisest choice. You may have heard that gasoline can be successfully added to diesel fuel, but be wise and learn to immediately separate fables, from facts. There are better options.
So how do I cope with cold weather? Clean filters, clean injectors, working glow plugs with pre-chambers that are free of carbon, and maintain properly adjusted valves. As for fuel, I go to the pump and buy good ol’ dino diesel. I don’t have to collect, wash, titrate, filter, or worry about the mess, and sometimes reliability issues that are associated with V.O., or biodiesel. Yes, I do pay more for fuel, and while the (false) allure of free driving is enticing, it is important to remember, there is no free lunch. – Rick B.