Diesel engines?

I think you have mentioned them before. One site I checked claims 135hp@3800 RPM. Seems like a lot of revs for a diesel . This chart shows max cont. RPM is 2300. And this article says 3800 rpm engine speed and 2300 prop speed. I guess that explains it.

HP/l is over twice what they show for the Lycomings. Is this due to the turbocharger and high compression ratio?

I did a little reading at "how stuff works" and noticed the large engines in locomotives and ships are two-strokes (intake ports for air, direct injection and two or four valves for exhaust). I was going to ask about two stroke diesels for aircraft but managed to find this article.

Is the Thielert 125 a two-stoke? (tired of looking) :)