I'm a bit puzzled at the posts above that make disparaging remarks about a diesel engine's "acceleration". Do you mean throttle response time - which is likely to be more instant than a carburated petrol engine? Or are you thinking of the acceleration of the Volvo estate your inadequate bhp diesel was attached to, and not the engine at all? Perhaps youve never seen class one powerboats in action. Diesel vs Lamborghini on equal terms.
I hope you dont practice slam accelerations on your Lycomings or, God help you, Continentals - when would that ever be needed? Not too good for Bristol Mercurys either, I seem to recall.
A diesel made in Northamptonshire was displayed at the PFA Rally last year, going for certification & to run on Avtur. 2 cyl 2 crank double acting two stroke, 120bhp same size, weight and mountings as a Lycoming, Bolt it right into your C150. A masterpiece of engineering.
I hope they make a commercial success of it. It would open a huge market for small long range aircraft, and particularly bush operations where avgas is hard to find, but dieso & Jet A1 is everywhere.