I am doing a trade study for small (~10kW) Diesel Engines; here are a list of the companies I have looked at:
Hatz
Lombardini
Izuzu
Kohler
Yanmar
Briggs and Stratton
Wisconsin Motors
Zenith
Caterpillar
Subaru
Cummins
Kubota
Perkins
There are also some non standard UAV engines that I’ve looked...