Ed

A lot of modern diesels are produced for competitive work in former Soviet/Eastern bloc countries. Not surprisingly some have what we in the West may perceive as "weird" names (JAK, FORA, CYCLON, PARRA etc).

As for large engines:

1. They cost more to produce than equivalent glow engines.
2. Piston/liner seal is more critical than with glow engines.
3. Fuel costs more (most IC flyers don't know of the diesel's frugality of consumption) and commercial availability outside of the US is patchy.
4. There is a perception they are difficult to start and operate. Smooth linear throttling can be problematical on some engines.
5. In days of yore it was believed large diesels (over the 3.5 cc class) were unfriendly to use and vibrated a lot.
6. When peaked to max RPM's, brown to black goo generation, which some flyers recoil in horror at.

I am sure many others will chime in with thir views.