Motorcycle engine cylinder and cylinder arrangement

Release date: 2020-07-10

Single cylinder engine

Single cylinder four stroke engine, crankshaft rotates two cycles to burn again, so can clearly feel the engine work is intermittent, intermittent exhaust noise. Because of the above characteristics, single cylinder motorcycle gives a person a kind of momentum and rhythm.

At low RPM, single-cylinder engine working is not stable, easy to make the engine stops running. At high speed, big vibration.

Multi cylinder engine

More than two cylinders engine called multi cylinder engine. Multi cylinder engine has many advantages, such as stable operation, smooth, is conducive to improve the speed of the engine, to increase power. Its disadvantages are of large size, heavy weight, more complex structure.

Straight engine

Each engine cylinder and crankshaft direction into a column mounted engine called straight engine. On motorcycle engine, often arranged transversely on the frame, so it is also called parallel engine engine.

V type engine

Engine type V history than the straight engine history is long. In on the V engine, to the layout of the two cylinder rod mounted on a crank pin, so that the crankshaft is substantially shorter length. The engine can greatly reduced in size and weight, so that the direction of the light and flexible motorcycle.

The V engine has many advantages, its disadvantages are the inlet and exhaust pipe structure of the complex.

Cylinder angle

In on the V engine, to the layout of the two columns between the cylinder to form a certain angle, the angle is called the cylinder angle. The angle size will directly affect the cylinder ignition interval, also will affect the engine vibration characteristics.

On the V2 engine, cylinder angle is small, the engine work produced was the stronger sense of rhythm. In fact, the V2 engine rhythm than single cylinder engine are strongly. Harry van V2 engine cylinder intersection angle is 45 degree.

In the 90 degree cylinder angle, to the layout of the two cylinder produced by vibration force can cancel each other out. Many manufacturers have adopted an included angle of 90 degrees V engine, such as Ducati, moto Guzzi and Honda Corporation of japan. In Japan, other manufacturers are not used at 90 °V type engine. This is probably from general arrangement angle consideration, or and patent right.

Horizontally opposed engine

Cylinder angle 180 degrees V engine is a horizontally opposed engine. BMW's boxer is horizontally opposed engine.

Engine arrangement

Engine arrangement includes two work. One is the layout of the engine itself, this work is mainly the cylinder layout scheme selection, two is arranged on the engine on a motorcycle, this work is the main engine layout direction. Cylinder arrangement scheme selection is very important, because it and motorcycle general layout, and the direction of the steering handle, but also with the engine on the frame layout direction.

Engine in-line arrangement or V type layout greatly affect the engine crankshaft structure shape, and are not the same. In the inline engines, each crank pin mounted on a rod, in type V engine, each crank pin mounted on the two connecting rod.

The engine on the frame of the layout work, mainly is the choice of engine arrangement direction, whereby the transverse engine or longitudinally mounted engine. The crankshaft and the vehicle direction at right angles to the called transverse engine, crankshaft and the body parallel to the direction of the call longitudinally mounted engine, their features are as follows:

1 transverse straight engine

Horizontal straight engine motorcycle is the most popular a scheme of arrangement. This arrangement is easy to adjust the load of front and rear tire, can be a shortened wheelbase, easy to be arranged into the exhaust pipe, when the motorcycle runs at each cylinder to contact with the driving wind, air cooled engine is preferred this scheme.

The disadvantages are more, such as the length of the motorcycle engine, variable size width. Engine position is higher, also affect the seat position. Crankshaft to rotate and generate gyroscopic effect, hinder motorcycle turning roll motion.

2 horizontal V type engine

A lot of advantages, V type engine than the straight engine is shorter, so the layout is very convenient. Most of V4 engine.

3 longitudinal straight engine

This scheme makes the motorcycle width becomes narrower, two feet. When the motorcycle when the roll easily by foot centralizer. When using the shaft of the transmission, is also very easy to put on the direction of rotation of the crank turned 90 degrees, in order to directly drive the rear wheels.

Drawback is easy to make the motorcycle before and after the longer wheelbase, increased, and into the exhaust system layout is also very difficult. For the air-cooled multi-cylinder engine, rear cylinder cooling is very difficult.

Modern motorcycles are rarely used this scheme. BMW K series is a large sport motorcycle, with shaft drive, with a water cooled 4 cylinder engine, the engine is not straight, but levels dropped disposed on the frame, so that the height of the engine is reduced greatly, but also conducive to the intake and exhaust system layout.

4 horizontal V type engine

In the fore-and-aft direction, this arrangement is a short straight engine. Air cooled engine using this scheme, the rear cylinder cooling is not good. If it is a V type engine, two cylinder can be blown into the air, will not appear poor cooling problems. This model applies only to V4 below the engine, if V6 engine, since the engine size, will affect the seat arrangement.

All two stroke engine ( omitted)

1 axis V -- NSR500

2 axis V -- YZR500

4 - RG500 square cylinder

2 - KR500 parallel cylinder

The advantages of the engine forward

Requirement of engine forward for many reasons. Intake and exhaust system of engine forward requirements, mainly from improving the engine performance to consider. Forward, can make into the exhaust pipe bending part smoother, which helps to improve the engine 's exhaust efficiency.

Frame structure also requires the engine forward, this is mainly to prevent the frame and engine interference. In order to use the least material with high stiffness of the frame, the frame structure of each part has different requirements. For example, front bracket and a rear bracket near, as far as possible to design into a straight line, and a thick pipe connection. Thus, when the engine is vertically arranged on the frame, because the engine is higher, will make the frame and engine interference.

While the engine forward, can reduce the total height of the engine, thereby avoiding interference with frame.

Yamaha motorcycle, engine cylinder of anteversion angle of up to 35- 45 degree.