Quote Originally Posted by Matt167
the tractors that can use both probably have very low compression gasoline engines probably 7:1 or lower, which I think only needs like 60 or 70 somthing octane to run correctly, diesel probably has that kind of octane.
The thing about a Diesel engine is how it ignites the fuel. Diesel fuel requires a higher compression ratio then the typical gaser. A 350 Olds Diesel has a 22.5:1 compression ratio!!. The reason, to heat the air that is drawn in on the intake stroke to a high temperature so that when the Diesel is injected into the combustion chamber it ignites. This is why intercooling is really needed on a turbo deisel because the cylinder temperatures can get way to hot and cause a melt down.

Those Tractors your talking about had compression release on them so they could lower the compression to run gasoline. There have been a few around where I'm from in Saskatchewan because of the cold winters. But whatever you do never put gasoline in a Diesel thats designed just for Diesel. The thing WILL explode, literally. A Diesel uses the cetane rating instead of octane rating. Cetane rating is the time the fuel takes to ignite once injected. The higher the cetane number the quicker the fuel ignites. So thats some things to think about Diesel.

We also have a couple old combines with the old Chrysler 318 Polyhemi engines that we run kerosene through them before we park 'em for the winter. We just choke them out and a big cloud of white smoke rolls out of the stacks and there oiled up for the winter (no fuel stabilizer required).