Ed Huntress wrote:

Aha. I hadn't thought about the difference in the way the fuel burns in a
carburetted versus an injected compression engine.

Well, that's the way it was defined in the patent (which, beside, didn't
work and Diesel had to change it. - Cunning's book!)

Have you considered a solenoid pump for your model? I don't have any reason
to believe it would be the answer, but I'm curious.

Solenoid not, but something like a piezo might be an option.
But as soon as you have a plunger, you have trouble. The necessary
tolerances are in the 1/1000mm range. I made some tests that looked
quite encouraging. The plunger has to have a diameter of about 0,7mm and
be in the 5mm lenght range, minimum stroke is about 1mm (all for
100ccm). Fun lapping it.


If you do, please let us know.

The person I'm talking about is still alive, and I have seen his cute
Diesel model.


There probably are some papers on it, buried deep in the archives at MIT's
Sloan Automotive Lab, or in Germany, in Rudolph's papers. I've never tried
that route because it's just a hobby question. Maybe when I'm retired. g

The whole thing is more a mechanical problem than a theoretical. You
need valves that are tight at 40..80 bar, open/close with only a slight
lift, need plungers and cylinders that fit 1/1000mm, ...
And even if I get it working, the model I'm planing to build doesn't
inject fuel directly, but uses compressed air to blast the fuel in. Now
making a compressor (two stage, 1:40) in the size of your thump is yet
another challenge ...

I'm not decided how the next engine will be fired.

Nick
--
Motormodelle / Engine Models
http://www.motor-manufaktur.de