Designed for 250–500-ton inland transport vessels, 9–12-meter yachts, and passenger boats, the Yuchai YC4A Marine Main Engine provides stable and efficient main propulsion power for light and medium-duty marine applications. By combining robust structural design with advanced electronic control and combustion technology, it delivers a well-balanced solution focused on reliability, economy, safety, and environmental performance.

High Reliability

The cylinder block and cylinder head use high-strength alloy cast iron, which improves structural rigidity and durability. An integral crankshaft further enhances strength and operational stability. Through in-depth reliability development and validation, the engine achieves a major overhaul interval exceeding 10,000 hours, ensuring dependable long-term service for daily marine operations.

Energy Saving

Advanced in-cylinder three-dimensional combustion CFD technology optimizes the combustion process and reduces emissions. In addition, a high-pressure common rail system, high-performance combustion chamber design, and optimized intake swirl ensure more complete combustion and excellent fuel efficiency. Yuchai’s proprietary piston ring sealing technology further reduces lubricating oil consumption by more than 50% compared with domestic engines in the same power class.

Safe and Comfortable Operation

Digital intelligent local and remote monitoring instruments allow real-time monitoring and protection of engine operation. Meanwhile, an integrated cast iron freshwater-cooled exhaust manifold effectively lowers engine room temperature. As a result, onboard operation becomes safer, more stable, and more comfortable during long-term service.

Environmentally Friendly

Full electronic control technology enables the engine to meet China Stage II marine emission standards and IMO Tier I requirements. Therefore, the YC4A supports cleaner operation while helping vessel operators comply with current environmental regulations.