Fries'Car - Vegetable Oil Car With Arduino

We are currently finishing our second master degree in industrial engineering and therefore we had to design an electronic system which would have to work with an Arduino card.

As one of us use to work on cars for hobby he propose us a really good idea! He uses a car which he tinkered to make it work on vegetable oil. The only problem is that the oil could be solid at an ambient temperature so it has to be pre-heated. In the same time, when the engine stops the oil has to be removed from the duct to avoid solid matter when the oil would cool down. The trick is to use a tiny diesel tank to start the car and when the motor would be hot enough, the oil (now liquid thanks to the heat) can be used as fuel. In the meantime as the motor stops a pump would begin to push the remaining oil by injecting diesel in the ducts. The vegetable oil would be sent in the diesel tank which is not a big problem because it would be diluted. For this solenoid valves, pumps, sensors were required but to command all of it an Arduino card was paramount !

Working for us is good but sharing our work with everyone is better, we'll explain to you how to realize our project !

Step 1: List of Material

The material required is easily deducted :

- A car you don’t care much

- 2 electric fuel pumps

- Vegetable oil filter

- A plate heat exchanger

- 4 two-ways solenoid valves

- Arduino Uno

- A computer to code the program

- An autoradio box (without the autoradio)

- An LCD screen

- 2 4-relays Boards or 3 2-relays Boards

- Wires

- 2 switches

- A temperature sensor

Step 2: Mounting in the Car

For this part, a little skills in mechanics are required.

To adapt the car for bi-fueling you need another tank with start and return lines which go to the vegetable oil solenoid valves. Fuel hoses must have a minimum diameter of 8mm because the oil is more viscous than diesel and generate more pressure drops.

With low quality Chinese solenoid valves you have to be careful with the way of mounting to not destroy it.
Be really careful with air infiltration to fuel hoses. You have to correctly seal it with hose clamps.
To connect the heat exchanger to the liquid coolant system you have to cut in the hoses of the interior radiator before the regulating valve and put T’s. This prevent hydraulics problem in the liquid coolant system. Use fuses to protect all electrical components and prevent short-circuit.
To prevent high resistivity and overheating, use also the right diameter of electrical wires. Make sure all the components are tightly fixed and can’t hit moving parts of the engine or drivetrain.
For skilled mechanics, you can also slightly change injection timing of the injection pump and increase injectors opening pressure to 180 bar. This improve the combustion process with a better atomization of the vegetable oil resulting in better mileage.

You will find the schematic to follow attached.