A double cylinder motorcycle engine refers to an engine configuration with two cylinders arranged in parallel or in a "V" shape. Let's take a look at two common types of double cylinder motorcycle engines: inline twin and V-twin.
Inline Twin Engine:
- Configuration: The cylinders are positioned in a straight line, side by side.
- Firing Order: The firing order alternates between the two cylinders. For example, if one cylinder fires on the compression stroke, the other fires on the exhaust stroke.
- Combustion Process: The engine follows a four-stroke combustion cycle (intake, compression, power, exhaust) in each cylinder. The pistons move up and down in their respective cylinders, driven by the crankshaft.
- Shared Components: Both cylinders typically share a common crankcase, crankshaft, and camshaft(s). They may also share other components like the intake and exhaust systems, cooling system, and lubrication system.
- Balance: To counteract the vibrations caused by the firing of each cylinder, inline twin engines often incorporate a balancer shaft. The balancer shaft rotates in the opposite direction to the crankshaft and helps reduce vibrations, improving overall smoothness.
V-Twin Engine:
- Configuration: The cylinders are arranged in a "V" shape, with a specific angle between them (e.g., 45 degrees, 60 degrees, etc.).
- Firing Order: Depending on the V-angle, the firing order can vary. The most common firing orders are the 180-degree and the 90-degree configurations.
- Combustion Process: Similar to the inline twin engine, each cylinder in a V-twin follows a four-stroke combustion cycle. The pistons move up and down within their cylinders, driven by a shared crankshaft.
- Shared Components: The cylinders typically share a common crankcase and crankshaft. The camshaft(s), intake, exhaust, cooling, and lubrication systems may also be shared or partially shared between the cylinders.
- Balance: Due to the inherent imbalance caused by the V-twin configuration, V-twin engines often employ various balancing techniques. These may include counterweights on the crankshaft, offsetting the firing intervals, or the use of balance shafts.
Both inline twin and V-twin engines have their own characteristics and advantages. Inline twin engines tend to be more compact, lighter, and offer good fuel efficiency. V-twin engines, on the other hand, often produce more torque and have a unique sound and character. The specific design and performance characteristics of a double cylinder motorcycle engine can vary depending on the manufacturer, model, and intended application.