What do bore and stroke mean?

[OLily]

Bore refers to the diameter of the cylinder, while stroke is the distance between the top dead center and bottom dead center of the piston movement. Here are the relevant introductions: 1. The ratio of stroke to bore: The ratio of stroke to bore is the most fundamental and important structural element of an internal combustion engine. It not only has a significant impact on scavenging quality and heat conduction but also affects the engine's power and fuel consumption rate. It also influences the structure and dimensions of all components, thereby affecting the engine's vibration, specific weight indicators, and service life. 2. Principle: Two-stroke gasoline engines generally use loop scavenging, which means using fresh air-fuel mixture to expel the remaining exhaust gas in the cylinder through the exhaust port. From this, it can be understood that the more thoroughly the exhaust gas in the cylinder is expelled, and the less fresh air-fuel mixture escapes with the exhaust gas (this situation is called good scavenging quality), the greater the engine's power and the lower the fuel consumption rate.