What is a Four Stroke Combustion Cycle?

Most cars and trucks we see on the road today have four-stroke engines that operate using a four stroke combustion cycle. Continue reading to learn how these engines work.

Used Auto Part Buyers 1-888-586-5322

Used Auto Part Buyers 1-888-586-5322


Four stroke engines are internal combustion engines whose pistons complete four separate “strokes” in order to convert fuel into motion. Each stroke is completed as the piston takes a full stroke along the cylinder. The four strokes in a four stroke engine cycle are as follows: Intake, compression, combustion, and exhaust. Continue reading to learn more about each stroke and how the four stroke combustion cycle works.

Otto Cycle

Nikolaus Otto was the man who invented the four stroke cycle back in the late 1800’s. For this reason, the four stroke combustion cycle is also commonly referred to as the Otto cycle. In contrast, there is a man named James Atkinson that invented a single-stroke combustion cycle, appropriately called the Atkinson cycle. This cycle is applied in modern hybrid electric technologies. As for the four stroke engine cycle, here is a breakdown of each stroke:

Intake
During the intake stroke, the intake valves open, allowing the pistons to travel down along the cylinder, increasing the cylinder’s volume, and allowing the engine to “take in” a full cylinder of air and fuel. Only a tiny drop of gasoline is mixed with air to perform this stroke.

Compression
The air and fuel mixture within the engine’s cylinders is compressed when the intake and exhaust valves close and the pistons move back to the top of the cylinders. As the pistons move up, they compress the air and fuel mixture into the cylinder heads.

Combustion
At the combustion stroke, ignition takes place. This stroke begins at the second revolution of the cycle. Once the compressed air enters the cylinder heads, the engine’s spark plug ignites this air and creates power. This combustion forces the pistons to travel back down the cylinders.

Exhaust
At the exhaust stroke, the pistons travel back up the cylinders and the exhaust valves open. This ejects the residual air fuel mixture emissions through the exhaust valves and out through the tailpipe.

Old Car Engines

When your car engine takes a turn for the worst, you may feel overwhelmed at the thought of replacing it with a new one. After all, the cost of engine replacement these days is incredibly high. In fact, you could buy a perfectly good used car for the price of some brand new car engines! Fortunately, you have the more cost-effective option of purchasing a used car engine. To make the most out of broken down car engine, sell it to an Indianapolis used auto part buyer for cash on the spot. Then apply this profit toward a new car engine!

We Buy and Recycle All Used Auto Parts

Garden City Iron and Metal 1-888-586-5322

Garden City Iron and Metal 1-888-586-5322

Call Garden City Iron & Metal at 1-888-586-5322 to sell used car parts for cash in Indianapolis, Indiana. We buy and recycle any and all used auto parts, regardless of age or condition. We also accept parts from all other motorized commodities, including farm equipment, construction equipment, snowmobiles, jet skis, boats, watercrafts, scooters, motorcycles, RVs, and more! Request a free estimate, today.

This entry was posted in Used Auto Parts and tagged , , , , , . Bookmark the permalink.