Their systems are supposed to be used with veggie oil. Biodiesel is something different, and can be run with no modifications to the engine or fuel system. Runnning veggie oil can't be done without modifications. For veggie oil to burn properly it must be at temps of atleast 160F. Most folks accomplish this with combos of coolant and electric heaters in the engine bay. The Love Craft conversions are basically a glorified coolant heated fuel filter. Since it is heated with the engine coolant the filter temp is reliant on the coolant temp. So on a cold morning it take 10-15 minutes for the coolant to get up to temp which means that the filter takes atleast that long to get warm. So like I said previously the LC conversions are setup to start up cold veggie oil.
When high enough temps aren't acheived you end up gumming up the IP, the injectors, and the cylinder walls with veggie oil. When the piston rings get sticky with unburned veggie oil the veggie oil can start getting into the motor oil. This can cause the motor oil to polymerize, turns in to goo. Which will destroy the engine in no time.

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