Ed Huntress wrote:

This is a question that's interested me for some time: how small can you
make a diesel, one that runs on real diesel fuel (cetane +/- 45)?

Well, it seems the answer of 300..400cc is about right for a good
running Diesel.


There are, as I'm sure you know, some very small model diesels that run on
ether (ether/castor oil mixes for the 2-strokes). Someone in Pennsylvania
makes such a kit for home machinists.

Yes, but they do not use injection pumps, so they are not real Diesels.
Real Diesels do:
- not use a spark plug or any timed device to start ignition
- start burning the fuel by compression heat
- do the timing of the thermal process by the timing of the injected
fuel.

Those model diesels do compress the fuel-air mixture and their only way
to controll the timing is by changing compression. Also, the fuel
explodes all at a time. Not what a Diesel does.


Do you have any other ideas? I'm thinking of something around 100 cc.

It must be doable, not very good running, smoking and nailing. But that
would improve a model of an early Diesel. :-)
If I only could find that guy with his mini Diesel ...


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