Diesel engine question:
About a year ago I designed/built a 2500+ watt diesel gen/set using a "Hatz" 4.6 HP diesel engine. I have attempted on numerous occasions to find out what the maximum altitude this engine will start at, with no success whatsoever.
Note: At 18,000 feet MSL the pressure and air density are half that of sea level. An engine at this altitude would have half the "effective" compression ratio at starting.
Yanmar and Somo are other diesel engines that are popular in several OEM 5KW gen/sets.