Description

The main difference between a 4-stroke engine and a 2-stroke engine is that a 4-stroke engine goes through four stages, or two complete revolutions, to complete one power stroke, while a 2-stroke engine goes through 2 stages, or one complete revolution, to complete one power stroke. This means a 2-stroke engine can potentially produce twice as much power as a 4-stroke engine and also weigh less.

When it comes to engine lubrication, the difference between a 2 stroke and 4 stroke engine is that a 2 stroke engine has no valve train, timing gears, cams or pushrods, whereas 4 stroke engines do. A 4 stroke engine needs to circulate oil throughout to lubricate these moving parts, whereas a 2 stroke engine only needs to lubricate the components internal of the combustion chamber, which is achieved by mixing the correct oil to fuel ratio.

A 4 stroke is more efficient. This is due to the fact that fuel is consumed once every 4 strokes. 4 stroke engines are heavier; they weigh upwards of 50% more than a comparable 2 stroke engine. IN general, a 2 stroke engine creates more torque at a higher RPM, while a 4 stroke engine creates a higher torque at a lower RPM. A 4 stroke engine is usually much quieter. While a 2 stoke engine is significantly louder and has a distinctive, high-pitched “buzzing” sound. Since 2 stroke engines are designed to run at a higher RPM, they also tend to wear out faster, therefore a 4 stroke engine is generally more durable. That being said, 2 stroke engines are more powerful. 2 stroke engines are a much simpler design, making them easier to fix. They do not have valves, but rather ports. 4 stroke engines have more parts, therefore they are more expensive and repairs cost more. 2 stroke engines require pre-mixing of oil and fuel, while the 4 strokes do not. 4 strokes are more environmentally friendly; in a 2 stroke engine, burnt oil is also released into the air with the exhaust. 2 stroke engines are typically found in smaller applications such as remote-controlled cars, lawn tools, chainsaws, boat motors and dirt bikes. 4 stroke engines are found in anything from go-karts, lawnmowers and dirt bikes, right up to the typical internal combustion engine in your vehicle.



EngineTechTip