Factors That Affect the Engine Size and Power of a Motorcycle

The engine in a motorcycle determines a huge amount of the vehicle’s character. It also has a major influence on the size of the chassis and overall weight.

Almost all of the bikes on this list have four-cylinder engines. But one exception is the incredible Morbidelli V8 bike. This bike has a BMW car engine mounted on a home-built frame.


The engine is the heart of any motorcycle, and its size and power are crucial to a bike’s performance. The bigger the engine, the more powerful it is, but there are other factors that can influence a bike’s power and performance. One of the most important is engine displacement, which is the volume of the cylinders. The amount of air and fuel displaced by the pistons during each stroke is measured in cubic centimeters (cc) or liters.

In order to calculate an engine’s displacement, you need to know its bore and stroke. The bore is the diameter of each cylinder, and the stroke is the distance that the piston travels in each cycle.

The pistons can be either long or short, and this affects the power and torque output. Additionally, different engines use different combustion systems and ignition technologies. For example, some Harley-Davidson engines use a combination of magnetos with contact breaker points, while others have single or double overhead camshafts.


The number of cylinders and their arrangement on a motor determines how much power it can produce. More cylinders means more power and higher torque. More power and torque make for a more powerful vehicle that is able to carry a greater load or travel faster.

The best motorcycles have an engine that is designed for the type of bike it is in. For example, a V8 engine is perfect for racing bikes that require high-speed acceleration. However, a V4 engine is better for cruising and city driving.

V-8 engines don’t make for graceful, slim little motorcycles, but every now and then, somebody comes along with an inventive approach. Take, for instance, the Morbidelli V8, which shrunk a Cosworth V-8 design into a Lilliputian 90-degree longitudinal 32-valve layout. This created a balanced package of power and weight, though its frightfully expensive price tag and shaky financial footing resulted in just four production units and three GP victories.


The torque of a motorcycle is the amount of force (measured in joules or newtons) that is applied to turn the wheels. This is not to be confused with horsepower, which refers to the amount of power generated by the engine and transmitted to the wheels.

Horsepower and torque are often reported separately because they are based on different factors, but both of them are important to a biker. A high torque value will mean that you can use lower RPM to accelerate and you will feel more ‘grip’.

Torque is the tendency of a system to rotate an object about its axis and can be measured by multiplying the force applied by the crankshaft’s speed (usually expressed in rpm). This measurement is then converted to a ‘torque’ that is multiplied again to account for gears, sprockets or shafts with built in ratios, the wheel/tyre and the ground. This produces a specific acceleration which is then measured in units of ‘ft/lb’ or ‘Nm’.

Fuel consumption

Motorcycles are relatively fuel-efficient vehicles when compared to cars. Even the largest motorcycles can achieve a good deal of mileage without burning huge amounts of fuel. In fact, it is quite common for riders who can control their throttles to exceed the manufacturer’s rated fuel efficiency estimates.

A popular choice is the dual-cylinder engine. It produces power across a wider range of revs and is narrower than an inline-four, making it easier to fit into a bike’s frame. However, it does not produce as much power as a four-cylinder engine at higher revs.

Putting a V-8 engine into a motorcycle requires a lot of engineering and money, but it is possible. The PGMV8 motorcycle was built by Ludovic Lazareth and uses a Maser V-8. It has a chro-moly trellis frame and CNC-machined 7075-aluminum rear elements. It can reach speeds of up to 178 mph. It is the kind of crazy that we need more of!

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