Hi Dave,
Weight is usually the enemy of converting a diesel for aviation, that's one reason we don't see too many flying. and if they are purpose-built for aviation (being made light enough for a competitive power/weight ratio) the are just too costly.
And the 700 pounds of torque from a 230hp engine turning 2500 RPM is not possible.
Horsepower is just a way to express work (torque) done over a period of time (RPM)
To find horsepower:
Torque x RPM
Horsepower = ---------------------
5252
To find torque from a known horsepower @ a given RPM:
5252 x horsepower
torque= --------------------------
RPM
So if the engine is really making "only 230 hp" @ 2500 rpm, torque has to be 483.
These numbers are nearly identical to one of the lower HP versions of the TIO-540.
If the engine in question is really making 700 lbs of torque @ 2500, hp would be 333.
My guess is that the engine is making 700 lbs of toque but at a more "diesel" speed of 1750 RPM.
That would work for 230 HP and if were swinging a really huge prop, it could power a plane direct drive.
Pat.