Four stroke engines have powered automobiles around the world, ever since their invention more than a century ago. Despite the rise of electric cars, the four stroke engine still reigns supreme.
Inspired by Jean Joseph Etienne Lenoir’s work on two-stroke, coal-gas powered engines, Nicolaus Otto went on to develop a better internal combustion engine along with Eugen Langen.
Nicolaus Otto noticed that the Lenoir engine relied on differential in pressure to deliver power. He developed the first four stroke engine that compressed fuel-air mixture to drive the piston through the power explosion, which in turn, turned a crankshaft to transfer power to the flywheel. He also claims the credit for developing the carburetor and an electric ignition system in 1890.
The most basic of four stroke engines has a single cylinder-single piston configuration with two valves. Manufacturers went on to develop and refine this basic configuration model that relied on petrol as the fuel. Petrol four stroke engines are being developed for over the century. The parallel twin was developed as an improvement on the single cylinder, using two pistons to double power strokes per crankshaft rotation, resulting in a smoother power balance and transfer.
The basic four stroke engines gained further refinements by way of fuel injection, more valves and turbochargers to gain more power, better fuel consumption and reduced emissions.
However, there are challenges as well.
Four stroke engines are computer controlled in modern cars. However, routine maintenance checks can be performed to ensure a healthy running engine with long life.
Four stroke engines are the mainstay of cars and motorcycles, as well as portable tools and small aircrafts. Hence, efforts for constant innovation in design and development are undertaken to focus on improving reliability and fuel efficiency in the future.