singlecylinder

A single-cylinder engine is an internal combustion engine that uses a single cylinder and a single piston to convert combustion energy into rotational motion.

The core layout is simple: a piston in a cylinder connected to a crankshaft by a connecting rod, producing torque as combustion occurs.

Single-cylinder engines can be two-stroke or four-stroke; two-stroke designs fire once per crank revolution, while four-stroke designs fire every other revolution, shaping power and torque.

Cylinders may be air- or water-cooled; common layouts include vertical or inclined cylinder orientation and various valve configurations (side-valve or overhead-valve).

Advantages include simple construction, light weight, compact size, low cost, easy maintenance, and strong low-end torque.

Disadvantages include limited power density for a given displacement, higher vibration, relatively poorer high-speed balance, and, for some designs, higher emissions than multi-cylinder engines.

Applications are widespread in small machines and light vehicles. Common examples include motorcycles and scooters, lawn and garden equipment, portable generators, and marine outboard motors; historically, some early cars used single-cylinder layouts.

Historical note: The Benz Patent-Motorwagen (1885–1886) used a single-cylinder four-stroke engine designed by Karl Benz. Modern examples include air- or water-cooled single-cylinder engines used in small motorcycles, dirt bikes, and portable gasoline generators.

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