How to work a 4 stroke Diesel engine

The intake valve opens, and fresh air (containing no fuel), is drawn into the cylinder

As the piston rises, the air is compressed, causing itstemperature to rise. At the end of the compression stroke, the air is hot enough to ignite fuel.

Near the top of the compression stroke, the fuel injector drives fuel into the cylinder. The fuel immediately ignites upon contact with the hot compressed air.

As the fuel burns, the gas in the cylinder heats and expands, driving the piston

The exhaust valve opens, and the exhaust is driven out of the cylinder.

The valves are operated by a variety of mechanisms on diesel and four stroke engines. The engine illustrated here features dual overhead camshafts, sometimes abbreviated DOHC. These are usually driven by a chain or cog belt as shown here.

post by: Engineer ARIYAN