Horsepower, abbreviated as hp, is a measure of the power consumed or produced in a motor vehicle while cc, which stands for cubic centimeter, is a metric unit of measurement equivalent to 1/1000 of a liter of fuel. The rating of an engine in horsepower is normally given by the manufacturer at a specific speed of the engine.
The speed of an engine is normally given in revolutions per minute, or rpm. For example, an engine with a rating of 50 hp at 6,000 rpm generates 50 horsepower at a rotating speed of 6,000 revolutions per minute. Different engines are designed to generate usable power while running at different speeds. Single-cylinder engines, which are often installed in large displacement dual-sport motorcycles, tend to pick in power delivery at a speed of 6,000 rpm, a point at which other engines, including the parallel-twin engine in Kawasaki’s Ninja EX2250, start to produce usable power.
Displacement indicates the amount of fuel and air that a combustion engine can consume in one cycle or revolution. The fact that engine displacement, which describes volume, is different for different engines means that the cc is also different for different engines. This is why there are motor vehicle engines with 2500 cc, 2000 cc and even 1000 cc.