There's also a guy in Germany working on a conversion of the Duke to
twin Thielert diesels - the big ones doing 350 HP. He's got one
flying.

I read the article - wow that's a huuuuge bump in range over the
gassers eh? Didn't know Lyc wasn't supporting the TIO-541 anymore (I
think the P-Navajo has the same engine?) but doesn't surprise me as
I've heard they're quite finicky and must be babied more than most high
HP turbo'd piston engines.