Mechanical modification – This is fast becoming my method of choice for an alternative fuel automobile. Like I said before, I think that in order for the trend to catch on and in order for people to make it a viable part of their lives, it’s important that the day-to-day interaction be as simple as possible. For this to work, we have to make the refueling and maintenance of a vegetable-fuel car or truck as simple as going to the nearest service station as possible. The reality is that until there’s a vegetable oil vending station on every corner, alternative fuel owners are going to have to operate out of their homebase where they can have ready access to their supply. I guess in a pinch though, one could always head out to the local Walmart and pick up a dozen bottles of Wesson Oil…
Since we can’t make a veggie-oil distribution system spring up over night, the next best thing would be to simplify the steps they’ll need to take to fuel up. The biodiesel option mentioned earlier comes with the headache of mixing one’s own fuel. The mechanical option takes the chemistry out of the picture with a reasonably simple, one time modification to the car.
The concept is again pretty simple: vegetable oil does not have the low viscosity of petro-diesel which makes it harder for the engine to atomize and more difficult to force through the car’s fuel lines. Not only that, but if left to sit for long periods outside of the tank (in the lines, unburned in the engine, etc.) it will crystalize and corrode the system.
In order to address these issues mechanically, we’ll have to pre-heat the pure vegetable oil before delivering it to the engine (heated vegetable oil has a lower viscosity than room temperature or cold vegetable oil) as well as come up with a way to purge the system of unburned oil before the engine is shutdown.
The sytems sold by greasecar.com consist of the following (taken from their website):
Fuel Valves (2)
Wire Harness & Connectors
Fuse and Harness
Lighted in Dash Fuel Gauge
Lighted 3-Position Switch
Heater Hose
Window Decal
Instruction Manual
5 Micron Bag Filter
Hardware
Hose Brackets
Heated Fuel Line
Fuel Hose
Hose Clamps
T-fittings
Large Hose Clamps
Heated vegetable oil tank
Heated 10 micron fuel filter
The bulk of the hardware includes an auxillary fuel tank with an internal heater and fuel valves to turn on and shut off the flow of the veggie-petrol. The first addresses the issue of heating the oil while the second allows the unused portions to be isolated from any parts that would deteriorate with time.
The trick to purging the fuel lines is the auxillary tank for the vegetable oil. By leaving the standard petro-diesel fuel delivery system in place, the driver can start and run the car with regular diesel fuel while it reaches operating temperature and can switch it over for the last few minutes of driving with to purge the line. Although this makes the operation less than 100% reliant on the alternative fuel method, it’s close enough for me. If you’re super particular, mix up a batch of biodiesel just for this purpose.