Resurrection of 2-stroke Engines : Future of Power

These days 4-stroke engines are backbone of every industry from automobile to aerospace. These engines are good but the power to weight ratio is not so good and even power is delivered at every 3rd stroke in a cycle. If you have an old yamaha motorcycle than you probably know about the 2-stroke engines they were powerful noisy and pollution causing which was the main reason why these 2-stroke engines came to a dead end, these are used today also but at smaller scale compared to 4-stroke. The reason for unpopularity of 2-stroke engines is that they are less efficient to their 4-stroke counterparts as the air fuel mixture does not get completely ignited which causes many effects like less power, knocking effects, pollution etc. despite of the fact that they are cheap, simple, high power to volume ratio 4-stroke is generally preffered. 

Several engine makers like Nissan, KTM, are in the verge of resurrecting the 2-stroke engines again with the help of latest technologies and advancement. The new 2 stroke engines which contains several technologies like Direct Fuel Injection, Statified Charge Combustion, latest electronic controls and much more which will deliver high performance and fuel economy without having any issues with stringent emissions. The secret of such high performance of new 2-stroke engines lies in the fact that the highly atomized fuel spray that is injected into the Combustion Chamber towards the end of compression stroke which burns more effectively. The fuel is sprayed after the exhaust valves are closed so that no fresh fuel is wasted which was a big problem in conventional 2-stroke engines. 

Schematic of a direct fuel injection 2-stroke engine 

With stratified combustion the combustion process becomes smooth as the flame is ignited by igniting small amount of air fuel mixture near the spark plug.The advance electronic helps in tracking and optimizing of the engine loaf and controls do that it can be more effective.