Multi-cylinder engine

For multiple-cylinder steam engines, see Compound steam engine and Triple-expansion steam engine

A multi-cylinder engine is a reciprocating internal combustion engine with multiple cylinders. It can be either a 2-stroke or 4-stroke engine, and can be either Diesel or spark-ignition. The cylinders and the crankshaft which is driven by and co-ordinates the motion of the pistons can be configured in a wide variety of ways. Multi-cylinder engines offer a number of advantages over single-cylinder engines, chiefly with their ability to neutralize imbalances by having corresponding mechanisms moving in opposing directions during the operation of the engine. A multiple-cylinder engine is also capable of delivering higher revolutions per minute (RPM) than a single-cylinder engine of equal displacement, because the stroke of the pistons is reduced, decreasing the distance necessary for a piston to travel back and forth per each rotation of the crankshaft, and thus limiting the piston speed for a given RPM. Typically, the more cylinders an engine has, the higher the RPM's it can attain for a given displacement and technology level, at a cost of increased friction losses and complexity. Peak torque is also reduced, but the total horsepower is increased due to the higher RPM's attained.