I suggest doing a little more research on the WVO or VVO conversions for older passenger car diesels too.
Compact utility tractors are easy because the diesel technology is generations behind passenger car technology. As far as I know, they are all still mechanically injected. And most more modern injection systems (from the 80's or so) should have the correct Buna rubber for the seals, so compatibility is simple. Most technology for older mechincally injected passenger car diesels will work. Your brand of choice. Personally I would work with a company like GreaseCar to establish what I needed.
The challenge comes with the viscosity of the VO and the glycerin. Both not an issue with #2 diesel. First, as ModMech mentioned, the viscosity is an issue delivering fuel at the required rate to the IP. Once in the IP, the IP will work harder and therefore theoretically wear more than normal trying to squeeze the fuel through the lines and injectors. At relatively mild temps, the viscosity greatly increases and begins to cloud (I think 40 degrees F is typical for veggie oil) futher slowing or stopping fuel delivery. Heating the VO has been the method of choice for most, usually at the lines and tank.
The glycerin is another animal. The glycerin in the VO will act like glue unless burnt off at very high temps. Normal operating temps seem to work, however warm up and cool down cycles are often run on VO package conversions by switching tanks to diesel. This allows the cold engine to fire on clean diesel until warm and also purges the VO before you shut it down. If you don't do this, the glycerin with form a varnish in the combustion chamber and within the injectors. It definately will clog injectors and gum up rings and pistons. Now a few people have been fairly suscessful AFAIK with super heating the fuel at the IP to combat both issues. But they have also large electrical demands and of course some have gone a little overboard and melted the IP seals.
Now most of this work has been done for either pure virgin VO or waste VO. If you were to grow a plant for fuel, as Soundguy mentioned, rapeseed oil should be better. Much less glycerin AFAIK. Jojoba is supposedly a great oil producing plant and fuel source as well.
All of this is learned info, as I am building a pilot batch plant for biodiesel. Was thinking along your lines as well but wanted more flexibility and use in more than one diesel.
Please be a little more patient with the group. People here will typically offer up advice when they have information to pass on and will not weigh in if they have nothing to add. And typically, this is a crowd (with notable exceptions) that only use their tractors for a few chores. Most find no reason to use an alternative fuel in our tractors to save 15-20 gallons of diesel per year.
With that being said, please share any info that you come across or your own experience. I for one, am interested in alternative fuels.
