1 Cylinder Diesel Engines
From Tom on the 33 hp:
This model is 528 lbs - for a 1 cylinder engine, a lot of the weight is probably in the flywheel. It looks "topheavy".
It has a fuel tank, other models come without the tank.
Specs also says water cooled via evaporative cooler, but I don't see the cooler.
Dimensions: 35.4" H x 29.9" W x 18.9" D.
Questions: Does it come with an electric generator / alternator? How is the "hand crank" feature accessed? What is the layout for mounting bolts? How is the throttle connected / actuated? Fuel / oil filters - are they available? Fuel tank capacity? What capacity for the water cooler? What size output shaft / flywheel layout? Do you have an engine yet?
What are your thoughts for building a cube - will it be integral in a tractor frame or removeable?
Higher Cylinder Engines
There appear to be much larger air-cooled engines - 6L - High Quality BF6L913 Diesel
- $4-8k for a 120kV 6 cylinder diesel genset -  - 120 hp continuous