OT Nominate the Best Auto and Aero Piston Engines in History and the Worst
I'll probably get some flack for this but for best
Automotive-Small Block Chevrolet. Maybe not the highest tech but it still fifty years after it came out still manages to compete both in the truck market but in the high performance market as well. Closely followed by the Cosworth V-8
Aero-Pratt&Whitney R2800 18 cylinder radial. True the merlin may be more storied, the R4360 more powerful and the Napier Sabre more daring in its design but the R2800 was in production up to the early 60s. A close tie would be the Wright R3350
Automotive-absolute bottom of the barrel is the Vega 2.3 liter all aluminum rolling smog bank
Aero-This is the hard one since anything that actually made it into production had to be reasonably reliable. The Rolls Royce X engine intended for the Manchester bomber. Proving even the House of Merlin could build a dog
Is my bias showing
The optimist says the glass is half full, the pessimist says it's half empty. The paranoid in me says somebody put a hole in it.
Remember pessimists are at heart opptomists. They know things can and will get worse.