Many reliabilty issues were maintenance and crew and witchcraft old wives tales related. It has beggared belief what some of the idiots I have met have done and said with /about radial engines. I tell them set them up as per the manual and fly them so and they will give good service. They might look steam traction engines but they require precise adjustment and management.
For me:
R 1830 is bullet proof
R 2000 dont like any abuse.
R 2800 is bullet proof.
Of course any fool can break them with witchcraft and old wives tales.