What are the types of piston shapes in automotive engines?

[Leonardo]

Automotive engine pistons come in various shapes including flat-top, convex-top, concave-top, and shaped-top. The piston crown is an integral part of the combustion chamber and is often designed in different configurations. Gasoline engines typically use flat-top or concave-top pistons to create a compact combustion chamber with reduced heat dissipation area and simpler manufacturing processes. Convex-top pistons are commonly employed in two-stroke gasoline engines, while diesel engine pistons often feature various concave designs on their crowns. Engine working principle: 1. Mixing air and gasoline in a specific ratio to form combustible mixture; 2. The intake stroke draws this mixture into the cylinder where compression ignition generates thermal energy; 3. High-temperature, high-pressure gases act on the piston crown, driving linear reciprocating motion that converts to mechanical output through the connecting rod-crankshaft-flywheel mechanism.