Water-cooled motorcycle engines are typically found in larger displacement ranges, primarily to manage the increased heat generated by more powerful engines. Harley-Davidson, for example, offers water-cooled engines in their Touring and Trike motorcycle models, with the Milwaukee-Eight 107 (107 CID, 1750cc) and Milwaukee-Eight 114 (114 CID, 1870cc) engines featuring liquid-cooled cylinder heads. These engines are designed to enhance the motorcycle touring experience by delivering more power, quicker throttle response, and improved ride quality.
Advantages of Water Cooling for Motorcycle Engines
Improved Heat Management
Water cooling is generally more efficient than air cooling, as it absorbs and discharges engine heat more effectively. This results in lower operating temperatures, allowing the engine to produce more power without overheating.
| Cooling Method | Efficiency |
|---|---|
| Water Cooling | Higher |
| Air Cooling | Lower |
Suitability for High-Performance Engines
Liquid cooling is particularly beneficial for high-performance motorcycles with high rpm engines, as they generate more heat than lower rpm engines. However, high rpm engines also require increased lubrication and piston cooling, which can be achieved through oil circulation.
| Engine Type | Heat Generation |
|---|---|
| High RPM | Higher |
| Low RPM | Lower |
Mitigating EPA Regulations
It is essential to note that the size of the engine has little to do with the heat it generates. The EPA’s mandated lean fuel mixture is primarily responsible for the heat in newer motorcycles. Parade mode is a temporary solution to this issue.
| Factor | Impact on Heat Generation |
|---|---|
| Engine Size | Minimal |
| EPA Regulations | Significant |
| Parade Mode | Temporary Solution |
Water-Cooled Motorcycle Engines in the Market
Harley-Davidson Milwaukee-Eight Engines
Harley-Davidson’s Milwaukee-Eight 107 engine has a displacement of 107 CID (1750cc), while the Milwaukee-Eight 114 engine has a displacement of 114 CID (1870cc). Both engines feature liquid-cooled cylinder heads for improved cooling and performance.
| Engine Model | Displacement |
|---|---|
| Milwaukee-Eight 107 | 107 CID (1750cc) |
| Milwaukee-Eight 114 | 114 CID (1870cc) |
Liquid Cooling Efficiency
Liquid cooling is more efficient than air cooling, with lower operating temperatures and higher power output capabilities. This makes it a preferred choice for high-performance motorcycles.
| Cooling Method | Efficiency |
|---|---|
| Liquid Cooling | Higher |
| Air Cooling | Lower |
Conclusion
In summary, water-cooled motorcycle engines are typically found in larger displacement ranges, primarily in high-performance touring motorcycles. They offer improved power, efficiency, and ride quality compared to air-cooled engines. However, the choice between air-cooled and water-cooled engines ultimately depends on the rider’s preferences and requirements.