Moving to the block, the cylinders looked surprisingly clean. There was also no debris in the oil pan, which can happen when parts of the block break. As such, almost everything was intact, including the bearings and pistons, albeit the latter damaged the rings, letting oil leak into the combustion chamber.
With that said, the Miata engine burned oil and smoked badly. A faulty oil system can cause overheating because it is essential to the engine cooling system. When overheating occurs, parts tend to expand and eventually become damaged. Do yourself a favor by following the prescribed oil change intervals. It can save you from an even more expensive engine replacement.
