See animation. A four-stroke engine is an internal combustion engine in which the piston completes four separate strokes during two separate revolutions of the engine's crankshaft, and one single thermodynamic cycle. the cylinder compressing the air or fuel-air mixture into the combustion chamber of the cylinder head. English: Animated scheme of a four stroke internal combustion engine, Otto principle: Intake stroke - Air and vaporised fuel are drawn in. Compression stroke . A four-stroke engine (also known asfour-cycle) is an internal combustion engine in which the piston completes four separate strokes which comprise a single. Animated illustration and description of the four stroke engine. As the piston rises, the poppet valve is forced shut by the increased cylinder pressure. Flywheel. A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either . The Atkinson-cycle engine is a type of single stroke internal combustion engine invented by. Working of 4 stroke engine with animation tightly within cylinder using piston rings to minimize the clearance between cylinder and piston!.