| A motorcycle engine is an engine found in a | | | | makes their famous flat-twin ("boxer twin")engine |
| motorcycle, which serves to propel the motorcycle. | | | | where the cylinders are horizontally opposed, |
| The motor typically sits immediately under the fuel | | | | protruding from either side of the frame. The boxer |
| tank, in between and just forward of the rider's legs. | | | | is one of two twin-cylinder arrangement that is |
| Types of Engine | | | | inherently balanced, producing very low vibration |
| Four Stroke Engine Engine configurationAlmost all | | | | levels without the use of counterbalance shafts. The |
| commercially available motorcycles are driven by | | | | 90-degree Vee, like Ducati and Moto Guzzi use, has |
| conventional gasoline internal combustion engines, but | | | | perfectly counterbalancing primary forces and minor |
| some small scooter-type models use an electric | | | | secondary imbalances acting in a plane perpendicular |
| motor. | | | | to the centerline of the Vee as viewed from the |
| Gasoline engines can be compared by many criteria. | | | | side. That also produces very low vibration levels. |
| Displacement | | | | Narrow angle V twins vibrate. [1] Sunbeam produced |
| Displacement is defined as the total volume of air | | | | a water cooled inline twin driving a propshaft. |
| fuel mixture an engine can draw in during one | | | | Narrow-angle V-twin engines dominate the cruiser |
| complete engine cycle. In a piston engine, this is the | | | | motorcycle segment. |
| volume that is swept as the pistons are moved from | | | | Three cylinders |
| top dead center to bottom dead center. To the | | | | Three-cylinder designs are unusual — they |
| layperson this is the "size" of the engine. Motorcycle | | | | are referred to as "triples" and are normally inline |
| engines range from 50 cc (cubic centimetres) to | | | | triples in layout. The British Hinkley built Triumph and |
| 2300 cc. | | | | Italian Benelli are two of the motorcycle |
| Number of cylinders | | | | manufactures using triples in their large displacement |
| Motorcycles have mostly, but not exclusively, been | | | | motorcycles. |
| produced with one to four cylinders, and designers | | | | On the other hand, in a two-stroke world triples |
| have tried every imaginable layout. Engines with more | | | | were more common. In the 70's Kawasaki had its |
| cylinders provide more power for the same | | | | 250, 350 500 and 750 triples which were known for |
| displacement, and feel smoother to ride. Engines with | | | | their power (but maybe not rideability) and Suzuki |
| fewer cylinders are cheaper, lighter and easier to | | | | had 380, 550 and 750 triples of which the last one |
| maintain. | | | | was water cooled and thus gained the nick name |
| Single cylinder | | | | "Water Buffalo". All the others above were air cooled. |
| One-cylinder motorcycles are known as "singles," and | | | | Four cylinders |
| "thumpers" (for the sound they make). In most | | | | Four-cylinder engines are colloquially known as |
| singles, the cylinder points up and slightly forward, | | | | "four-bangers." They are quite similar to car engines, |
| spark plug on top. They are most common in | | | | and most commonly have a transverse-mounted |
| off-road and dual-purpose motorcycles, though there | | | | inline four layout, although some are longitudinal (as in |
| are some cruisers and small-displacement sport-bikes | | | | the earlier BMW K series). V-4 and boxer designs (as |
| that use single-cylinder engines. | | | | in the Honda Gold Wing series) have been produced. |
| Two cylinders | | | | One of the more unusal designs was the Ariel Square |
| Two-cylinder motorcycles are called "twins." The two | | | | Four, effectively two parallel-twin engines one in |
| most common arrangements are the "V-twin" where | | | | front of the other in a common crankcase - it had |
| the cylinders form a "V" around the crankshaft, which | | | | remarkably little vibration. |
| is oriented transversely (i.e., perpendicular to the | | | | Since the advent of Honda's CB750 straight-four |
| direction of travel). | | | | engine, straight-fours have dominated the non-cruiser |
| also common especially in classic British motorcyles | | | | street motorcycle segments. |
| and Japanese motorcycles, is the inline twin also | | | | Five cylinders |
| known as the parallel twin. In this design the cylinders | | | | Honda has produced a five-cylinder engine for racing, |
| are side by side vertically above the crankcase. If not | | | | the RCV, but no five-cylinders exist for commercial |
| vertical they are generally close to in order to | | | | production motorcycles. |
| maximise airflow cooling. | | | | Six cylinders |
| The angle in the V-twins varies from around 45 | | | | Six cylinder engines are uncommon, and found only |
| degrees to 90 degrees. Typical of the former is the | | | | on the biggest motorcycles. One of the best six |
| Harley-Davidson and Vincent engines which due to | | | | cylinder examples is the Kawasaki Z1300. Nowadays |
| their firing order tend to vibrate more. Ducati and | | | | the most famous six cylinder engine is the boxer |
| Moto Guzzi make V-twins cylinders at s 90 degree | | | | used on the Honda Valkyrie series and Honda Gold |
| angles to quell primary vibrations. Moto guzzi | | | | Wing. |
| motorcyles have had their engines crosswise in the | | | | More than six cylinders |
| frame one cylinder to the left, one to the right. | | | | A number of custom and one-off motorcycles use |
| The parallel twin engine configuration was made | | | | more than six cylinders. For example, the Boss Hoss |
| famous by Edward Turners Triumph Speed Twin | | | | motorcycle uses a Chevy V-8 motor. But no major |
| design as used on the Triumph Bonneville. BMW | | | | motorcycle manufaturer uses more than six cylinders. |