Very unusual fuels

[StrawHat]

Is anyone aware that in the early 1900's there were large diesel engines developed to run on coal dust! Back in those days a large amount of city electrification was done with large gas engines, steam engines of course, and specially designed diesels in the generating plants. Reciprocating steam engines were extremely inefficient and so were mostly replaced by some kind of internal combustion engine for electrical generation. Several decades later modern steam turbine generator plants were developed which were more efficient than any of the internal combustion engines!

Now if an engine can be made to run on coal dust, one could be made to run on charcoal too. Although charcoal doesn't pack as much energy as coal, it would still be workable.

On a side note, a piston steam engine could barely get 6% efficiency in most places, an "oil" engine would get 12-13% right off the bat. So there was an era where oil engines ruled in mines and mills before petrol or diesel engines came along. Gasoline (petrol) was once a nuisance by-product of making lubricating oils! An oil engine is not anywhere near a true diesel however, although some mistakenly call them a "semi-diesel" engine.

I wouldn't mind having an old "oil" engine just for fun. Not very efficient but would be fun to run one every once in a while. They once had a tractor that ran on oil engines, sort of like green acres. No reverse gear, you simply reversed the engine to go backwards using a trick of cutting fuel, then reapplying fuel just when the engine stalled.

[Willw]

Hi StrawHat, I think this is one of the tractors you are referring to.
https://www.youtube.com/watch?v=Rxdka2igpRk

I share your interest in old semi-diesels. I also have considered converting an existing engine to semi-diesel just for fun (maybe a Listeroid or hit and miss gas engine?).

I recently considered it with my 1920's Nelson Bros. gas engine (4.5" bore, 6" stroke, dual flywheels) which needed an entire top end; and I even went so far as to purchase a suitable sleeve and material to fabricate a cylinder with.
But the local historical value of the engine was such that I could not bring myself to do it, and sure enough I have obtained a used cylinder, head, piston, and rod for it.
So a restoration of sorts will be started on that one, depending on what the future holds.

With the Listeroid, I can't find a reason to justify the expenditure it would require (and do I really want to ruin a brand-new engine which I could possibly sell?).
Even if I did convert a Listeroid to semi-diesel, what would I have? Half of the people I showed it to would not understand what I was talking about when I explained what I did, and the other half who did understand, would probably condemn me for doing it .