>>If you look at what they've already done in terms of putting a 1.7L engine
(135hp) into a Piper Warrior (PA28-161) and getting performance equal to or
better than the stock Lycoming O-360 (160hp) then a little quick math
suggests that the thrust from a 310hp diesel might be about equal to the
thrust of  370hp in gasoline. Now THAT would be way cool.<<

At least one experienced pilot who has actually flown the 1.7L have reported
that the "thrust" was substantially "less" than what they would have
expected out of a 160Hp O-360. In one case, to the point that they felt it
would not be suitable for student pilot touch and goes.