Final answer:
Blank rings prevent combustion pressure from leaking into the engine's crankcase by ensuring that the compression pressure is contained within the cylinder.
Step-by-step explanation:
Blank rings prevent combustion pressure from leaking into the engine's crankcase. In an internal combustion engine, there are four strokes: intake, compression, power, and exhaust.
During the compression stroke, the piston moves up, compressing the air-fuel mixture. Blank rings ensure that the combustion pressure is contained within the cylinder, preventing it from leaking into the engine's crankcase.