It looks like the injector orfice would have to be microscopic.
The injector (?) at the top of the cyinder head looks pretty long, maybe a check valve in there?
The compression on a Detroit diesel is between 18:1 and 21:1.
The injector nozzle on a Detroit diesel engine is pretty small, so for a model, I would think a tiny nozzle.
I think the Detroit varies the stroke of the injector?
Maybe Find mentions that, it is a little hard to understand what he says on my sound system.
I am assuming that the injector pump is below the cylinder, at the end of the pipe from the injector at the head.
I would start by calculating the pressure inside the cylinder that has to be overcome by the injector pump first, then maybe look at nozzle sizes and find out how small a drill you can get, or maybe find a pre-constructed nozzle of a predetermined size.
And then maybe run on kerosene? Probably takes something a little more volatile than diesel fuel, but still considered one of the "oily" fuels.
Should not have to pre-heat the engine, since the air temperature inside of the cylinder is hot enough to fire the fuel.
Probably need some serious rings on the piston, and maybe a long piston.
Generally the entire engine has to be stronger due to all the forces.
Long stroke for sure.
Lets say you got a 1" bore, then the piston area would be 0.785 sq.in.
For a 1" stroke with say a 0.125" clearance, then the volume at BDC would be 0.8831 cu.in., and at TDC, the volume would be 0.098125 cu.in., for a compression ratio of about 9:1; too small.
For a 2 in. stroke, the ratio would be 17:1.
For a 2.5 in. stroke, the ratio would be 21:1.
Did I do the math right?
So use a 1" bore, and a 2.5" stroke.
And maybe look at welding orfices for the injector.
The orfice would have to be along the lines of a thin piece of hair I guess?
For an initial engine, just use a bash valve for the injector pump, and vary the amount of pump stoke manually until you get the injector worked out.
It can be done obviously (building a diesel injector and pump).
Go for it Chuck.
We want one too.
Edit: For a smaller engine, maybe a 0.75" bore, and a 1.125" stroke?
Edit02: A word of caution about injectors, too many would stick their finger over the end of the injector "to make sure something is coming out". This could be fatal since the injector will inject diesel fuel into your bloodstream. Don't make that mistake.
