|
I've known a few who have done the veggie oil diesel, one in particular.
A word about octane
Before talking about that I just want to mention that while diesels can run on several kinds of fuel the reason gasoline doesn't work is because of it's high octane. Gasoline needs to be hotter to ignite. So what happens is the injector fills the combustion chamber full of hot fuel, then BOOM! It all detonates at once and bye, bye engine. Diesels work by injecting fuel that starts to burn almost immediately. That way it burns as it's being injected. This controls the burn. Gasoline engines control the burn by a spark that starts the flame at one point and lets the flame travel to the ends of the combustion chamber. But if the engine is too hot, CR too high, too much boost, too much advance, too low of octane, etc., then even a small amount of gasoline that hasn't been burned yet can spontaneously detonate and potentially cause serious damage.
The reason LP and better yet CNG work is because they have such a high octane you could use them with a diesel like CR and spark ignition. Only you don't need a spark if you're injecting diesel fuel anyway since the diesel ignites immediately and starts the combustion process. You also add very little LP or CNG to reduce the potential of damaging the engine from detonation.
Bio diesel
A couple things to think about.
One is, yes, straight filtered veggie oil can work if heated up enough.
Second, if you process the veggie oil and "crack" it to take the glycerin out it becomes much more liquid and will work at temperatures down to about freezing. But that also introduces methanol which can eat certain rubbers and metals.
Third is once you get a contract to take away a restaurant's used oil for free, you have to take all of it. My buddy ends up getting way too much and can't hardly use it all, even driving a pretty long drive (+60 miles) every day in his Dodge Ram.
|