The Truck

The first Grease Machine (Left) which was totaled in a wreck on October 30th.  (Right) The new Grease Machine...

My vehicle is what you would describe as...unique.  It is a 2000 Ford F250 with a 7.3L Powerstroke V-8 Diesel engine.  This is not the remarkable part.  What is special about this truck is that it runs on used vegetable oil which I get from restaurants. 

Believe it or not, the diesel engine was originally designed to run on vegetable oil.  Rudolf Diesel, the inventor, was evidently attempting to make farmers completely independent, meaning they could produce the fuel that would run their tractors.  He is quoted as saying, almost 100 years ago, that although vegetable oil is not an important fuel source now, he could see a time when it would become important.

The science behind the vegetable oil conversion is very simple.  Vegetable oil at room temperature is too thick to use as a fuel, but if you heat it up, it thins out.  You can see the same thing happen if you heat a jar of honey in the microwave oven.  It eventually will be as thin as water.  To convert a diesel powered vehicle to run on the oil, you simply have to heat the oil up before it goes into the engine. 

The conversion process took me approximately 3 days to do.  During that time I had to install an auxiliary tank into the bed of the truck, run a long set of heater hoses from the engine compartment to the tank (for heat), and install a set of solenoid switches controlled by a switch on the dashboard of the truck. 

The fuel tank and the heater core "splice" which runs all the way to the fuel tank.

The heater hoses are connected to my heater core, which is normally used to heat the cab of the truck during the winter.  The coolant flows through the hose into a metal coil in the bottom of my fuel tank.  The fuel intake hose is located near this coil, so before the oil goes into the fuel line it is heated.  The fuel line runs INSIDE of one of the heater hoses that runs back to the engine compartment, so the oil is heated the entire way to the engine.  From there, the oil runs through a fuel filter, which is also heated, and from there the oil goes directly into the injector pump of the truck's engine.  That's it! 

Pictures:  (Left) The fuel filter for the vegetable oil (diesel filter is left intact) (Right) Miles of hose!

The electrical system of the conversion is pretty simple as well.  What I basically did was make two separate fuel systems for the truck.  I left the original diesel fuel system mostly intact, but connected the vegetable oil fuel system into the diesel system.  The beauty of this is that if you have a problem with the vegetable oil system, you can still run the truck off of diesel.  The solenoids control which fuel is used (veg oil or diesel) and where the "extra" fuel goes that isn't burned.  In a normal car engine, the fuel pump sends more fuel to the engine than it can actually use.  Normally, this fuel is returned to the tank.  In my system, this process still occurs when I'm running the truck on diesel.  As soon as I switch to vegetable oil, the extra oil is simply recirculated through the fuel filter until it is burned.

Shutting the engine down involves one extra step on this vehicle.  I have to flip the switch on the dashboard into a different position, which makes the solenoids change configuration.  The truck instantaneously flips back to diesel and forces the "extra" diesel back through the vegetable oil line and into the vegetable oil tank.  Why do this?  If I were to leave the oil in the fuel lines and in the engine it would eventually "gel" up and clog everything out.  The diesel simply cleans everything out.  Once this process is done (about 30 sec), I switch back to the normal diesel running mode and let it sit for another minute or so to burn off all of the vegetable oil in the system.  Then I shut it down.

Why convert a car?  There are many reasons, but the main factor for many people will be cost.  You can get used vegetable oil for free at many restaurants, and if you have to pay, you might pay up to $0.10 a gallon!  Another factor:  the environmental impact.  Vegetable oil powered vehicles have a reported 50-70% fewer emissions than normal diesel vehicles.  There are NO sulfur emissions (a big issue with diesel these days) and most other emissions are significantly reduced.  If I push the gas pedal to the floor, you WILL NOT see smoke come from the exhaust.

This is the first oil filtration that I did, which was much messier than it should have been.  Note the caption on the newspaper I'm standing on.  It shows a gas pump handle with the caption, "Face it, we're addicted."  I beg to differ.