v twin engine

The V Twin engine is a two-cylinder engine layout in which the cylinders form a "V". The V-Twin engine's pistons are aligned so that, if viewed along the line of the crankshaft, they appear to be in a V. The V configuration reduces the overall engine length and weight compared to an equivalent straight engine. The v-twin configuration allows for optimum torque for a given displacement. An engine is classified as a V-type if there are two banks of cylinders attached to a single crankshaft. The cylinders are usually positioned at either 90 or 60 degree angles from each other. This block is shorter in length and height than a corresponding inline block of the same cylinder count and displacement. Because these engines use a short, strong crankshaft they are better suited to tolerating higher rotational speeds and higher torsional stresses

A normal two cylinder engine fires the pistons in such a way that one fires on the first revolution of the crankshaft, and the second one first on the second revolution.

The most obvious configuration for a V-twin is a 90°, in which counterweighing can balance the engine, in odd firing 90 degree Vees. This is seen in the Moto Guzzi and Ducati, but other angles can be seen like the 45° of the classic Harley-Davidson engine, the 75° Suzuki, the 52° Honda, the 80° Honda CX-500, the 47° Vincent, the 42° Indian, and the 60° Aprilia.

The terms longitudinal engine and transverse engine are used to refer to the crankshaft orientation. The crankshaft orientation gives a correct method to determine engine orientations as it gives the same orientation for all V-engine types like V-2, V-4 and V-8.

Both two-cylinder V engines are common on motorcycles. The engine can be mounted in

The longitudinal two-cylinder V as seen on Moto-Guzzis and some Hondas is less common. This position is well adapted to transmission shafting. When used in motorcycles, this approach has the slight disadvantage of causing a torque reaction that tends to lean the motorcycle slightly to one side. However, many motorcycle manufacturers have corrected for torque reaction by rotating the transmission input shafts and the balance and drive shafts opposite that of the crankshaft so that there is approximately equal mass turning clockwise and counterclockwise at any time, thereby physically canceling the effect.

Engine balance is the design, construction and tuning of an engine to run smoothly. Engine balance reduces vibration and other stresses, and may improve the performance, efficiency, cost of ownership and reliability of the engine, as well as reducing the stress both on other machinery and on the people near the engine.

These benefits are produced by:

• Reduced need for a heavy flywheel or similar devices.
• Reduced wear.
• The opportunity to reduce the size and weight of components (other than the obvious one of the flywheel) as a result of reduced stress and wear.
• Reduced vibration transmitted to the surroundings of the engine.

The opportunity to extract more power from a given engine by:

1. Higher maximum operating speeds made possible by reduced stress.
2. Spreading loads equally over multiple components, for example if multiple carburetors are poorly balanced, the maximum available throttle will be reduced

In a true V-twin engine, for example Harley Davidson engines, the two cylinders share a single crank pin (also known as a journal) on the crankshaft, therefore the "twin" nomenclature. Two cylinder, V shaped engines with separate crank pins for each cylinder are more properly called "V-2" engines

In single pin crank type, the crankshaft has only one pin, and both pistons are connected to it (the single pin) through their connecting rods.

Whereas in a dual pin type, the two pistons are connected to the crankshaft at two different positions using two pins.

The former is the true V-twin engine whereas the other is V-2 engine.