What effect does a worn cylinder wall have on engine operation?

A worn cylinder wall significantly impacts engine operation mainly by reducing engine power. As the cylinder walls wear down, they can create a larger clearance between the cylinder and the piston. This increased clearance can cause a reduction in the seal that the piston rings create against the cylinder walls, which in turn leads to decreased compression within the cylinder.

When the compression is lower, the engine does not produce as much power, since an effective combustion process relies on a specific volume of air-fuel mixture being compressed to a certain degree before ignition. With compromised sealing due to wear, the engine can also experience increased blow-by, where combustion gases escape past the piston rings into the crankcase rather than being utilized for power production.

While improved piston ring seating might initially seem like a potential benefit of a worn cylinder wall, it actually exacerbates the situation as the rings may not seat properly in a worn cylinder, further diminishing performance. Similarly, a worn cylinder wall cannot improve fuel efficiency; instead, it challenges effective combustion and often leads to increased fuel consumption rather than a reduction. Ultimately, a worn cylinder wall negatively influences engine performance, leading to a loss of power and efficiency.