[thackney]

At 29% efficient, why would we want to mass produce them?

[Abathar]

Thats thermal efficiency, compared to a standard diesel or gas engine that is quite high if memory serves.

[Abathar]

"The largest compression-ignition engines are two-strokes and are used in some locomotives and large ships. These engines use forced induction to scavenge the cylinders. An example of this type of motor is the Wartsila-Sulzer turbocharged 2 stroke diesel as used in large container ships. It is the most efficient and powerful engine in the world, with over 50% thermal efficiency. For comparison, the most efficient small 4-stroke motors are around 43% thermal efficiency (SAE 900648), and size is an advantage for efficiency due to the increase in the ratio of volume to area."

oops, looks like you're right on that number. From the SAE writeup perhaps that is high efficiency for that type of engine, I was thinking of another thermal number in the upper teens, have to look for the chart I had earlier.