Propulsion system for a single engine propeller driven a/c

[ravachol]

for my design project, i have to consider a feasible prop systm for a single engine propellr driven aircraft and I am thinking about diesel engines. they seem very efficient and cheap for aircraft propulsion.
ill have a small number for power/ weight ratio but it will be cheaper and it wll use diesel fuel

can anybody offers turboprop or piston prop ?

 

[ravachol]

i think i didn't write the problem obviously.
I have to design a personal aircraft with 1600 km range and the pav must have one engine.

At first glance, I chose a turboprop engine but then aero-diesel engines became more reasonable for me.

If you have any opinion, I will be glad to hear