Engine Lubrication System Explained!

Engine Lubrication System

The video explains how engine oil protects an engine, the main parts of the lubrication system, and how lubrication differs between four-stroke and two-stroke engines.

Why Lubrication Matters

Engine oil forms a film between moving parts. This reduces friction and heat, limits wear, and helps the engine operate efficiently and last longer. An oil-pressure warning light can alert drivers to low pressure; gauges and a dipstick are used to check pressure or oil level.

Main Functions of Engine Oil

• Reduces friction and wear: Separates moving parts—including shafts and bearings—to prevent direct contact.
• Cleans the engine: Carries dirt and particles toward the oil pan. The oil filter traps smaller particles, while larger particles may settle in the pan.
• Cools components: Takes heat from moving parts and transfers it to the oil in the pan.
• Seals the piston and cylinder: Forms a seal between the cylinder walls and piston rings, helping reduce exhaust-gas blow-by.
• Cushions bearings: Oil between journals and bearings absorbs sudden heavy loads and helps reduce bearing wear.

Main Parts of the Lubrication System

• Oil pan or sump: A reservoir below the crankcase that stores oil. It is designed to withstand damage and may have a guard underneath to protect it from road hazards.
• Oil pump: Draws oil from the sump and sends it to the engine’s moving parts. Regular oil and filter changes help prevent particles from interfering with the pump.
• Oil filter: Removes small contaminants from the oil before it reaches engine components.
• Oil galleries: Interconnected passages, formed by drilled holes in the engine block and related components, that distribute oil to parts such as the cylinder head and overhead camshafts.

Lubrication in Four-Stroke Engines

Four-stroke engines store oil in a sump. They may use either of the following methods, or a combination of both:

• Splash lubrication: The crankshaft splashes oil onto engine components.
• Pressurized lubrication: A pump forces oil through the system to moving parts. The video describes this as the preferred method.

Lubrication in Two-Stroke Engines

Two-stroke engines can experience greater wear if lubrication is insufficient. They use a total-loss lubrication system, in which oil is combined with fuel to lubricate components:

• Oil injection: Oil is injected directly into the engine.
• Premix: Oil and fuel are mixed before being poured into the fuel tank.

Speakers and Sources Featured

• One unnamed narrator or voice-over explains the lubrication system.
• No other speakers or sources are identified in the subtitles.