Biodiesel Scope

Disclaimer* I don't know much about engines.

My family used to own an excavation company, and now there is a half dozen giant machines in my backyard (they all still run). I am wondering if ANY diesel engine can be converted into Biodiesel? Even the very big machines? Does the cost of the transformation increase as size of the machine increases?

No problems getting the engines to run, I've heard of combine harvesters running on sunflower oil in russia in the growing regions where sunflowers are grown for oil like rapeseed/canola in the US and europe.


The only problem that seems to crop up is that certain rubbers do not like biodiesel and perish or dissolve in short order. so replacing all seals and orings with biodiesel rated ones heads off that problem and otherwise it's a case of fill the tank and check the fuel filters and carry on.

The biodiesel will clean the tank and lines so you will go through a lot of filters quickly until all the caked on sludge is out and deposited on the filters. once clean they should stay clean, Biodiesel has a strong detergent type action on old diesel sludge.

Older diesel motors should have no trouble with running on it no matter the size.

The very first diesel engines actually ran on peanut oil.

Adam Geriak wrote:I am wondering if ANY diesel engine can be converted into Biodiesel? Even the very big machines? Does the cost of the transformation increase as size of the machine increases?

Hi Adam,

The short answer is "yes". Any diesel motor *can* run on biodiesel.

and as far as "transformation" - depending on the piece of equipment - "maybe".

Diesel motors made after about 1994 should have elastomeric ("rubber") components compatible with biodiesel so no conversion of the motor is required. This was due to the introduction of better fuel system materials introduced to support low sulfur diesel.

If your equipment is pre-1994, you'll need top replace fuel lines due to the strong solvent properties of biodiesel. And if there's other "rubber" components in your pre-1994 fuel system like gaskets and o-rings, they'll like start to leak over time as well.

That being said, poor quality fuel can clog filters and leave you by the side of the road (or missing your harvest window) at the worst possible time. Making good quality fuel is not difficult, but many people will cut corners and learn the lesson the hard way.

A good farmer friend of mine grows soy and canola on his farm and crushes some of the crop to make biodiesel and meal for his cows and turkeys. Although he has run his combine on his home made fuel, he prefers to use it in his lower risk farm equipment and remove the stress of introducing another variable into his harvesting operation. Biodiesel breaks down faster than diesel fuel which is great for the environment in case of a spill, but no so good in the tanks of equipment that doesn't get used every day - like combines, backup generators, and firetrucks.