Automotive Information- Stoke Cycle Flashcards
What are most engines built to utilize?
4-Stroke Cycle
This means that it takes 4 strokes of the piston to complete what?
One Cycle of Events
The piston movement from the top of its travel in the cylinder to the bottom and back again.
A stroke of the piston movement.
The 1st Stroke Cycle.
Intake
The 2nd Stroke Cycle.
Compression
The 3rd Stroke Cycle
Power
The 4th Stroke Cycle
Exhaust
The piston moves downward. This creates a low-pressure vacuum.
The intake valve begins to open.
Air is sucked in and fuel is injected into the air stream.
1st Stroke Cycle AKA Intake
Between the 1st and 2nd Stroke Cycle. The intake valves is almost closed once this concept is reached.
Bottom Dead Center (BDC)
The pistons start to move upwards.
Both intakes are closed.
This causes compression with the mixture of air and fuel, which causes heat.
This makes the air and fuel easier to ignite.
2nd Stroke Cycle AKA Compression
Between the 2nd and 3rd Stroke Cycle, just before the piston reaches Top Dead Center (TDC) what does this component do?
The Sparkplug fires and ignites the air-fuel mixture.
During this stroke cycle, the air in the combustion chamber is heated from the flame that the spark plug causes.
This causes a rapid expansion of the gases and making the piston move downward.
The intake and exhaust valves are both still closed to keep pressure and retain movement with the pistons.
3rd Stroke Cycle AKA Power
Between the 3rd and 4th Stroke Cycle. Before the piston reaches BDC, the exhaust valves begin to what?
The exhaust valves begin to open.
The gases are ready to be purged from the engine during this cycle, and the piston moves up in an upward motion.
As the gases are sent through the exhaust and into the atmosphere, the entire cycle is then completed.
4th Stroke Cycle- Exhaust
