What are differences between gasoline outboard engine and diesel outboard engine?

1. The way of injecting is different
Gasoline outboard motor generally injects gasoline into the intake pipe to mix with air to form a combustible mixture and then enter the cylinder. Diesel outboard engine generally injects diesel directly into the engine cylinder through the fuel injection pump and nozzle, and evenly mixes with the compressed air in the cylinder, spontaneously ignites under high temperature and high pressure, and pushes the piston to do work.

2. Gasoline outboard engine features
The gasoline outboard engine has the advantages of high speed (the rated speed of the Yamaha 60-horsepower two-stroke gasoline outboard motor is 5500r/min), simple structure, small size, light weight (the net weight of the Yamaha 60-horsepower four-stroke gasoline outboard is 110-122kg), and low noise during operation, small, stable operation, easy to start, low manufacturing and maintenance costs, etc.
Disadvantages of gasoline outboards motor:
A. The gasoline consumption is high, so the fuel economy is poor (full throttle fuel consumption of Yamaha 60hp two-stroke gasoline outboard is 24L/h).
B. Gasoline is less viscous, evaporates quickly, and is flammable.
C. The torque curve is relatively steep, and the speed range corresponding to the maximum torque is very small.

3. Diesel outboard motor features
Advantages of diesel outboards:
A. Due to the high compression ratio, the diesel outboard engine has lower fuel consumption than the gasoline engine, so the fuel economy is better (the full throttle fuel consumption of the HC60E four-stroke diesel outboard engine is 14L/h).
B. Diesel outboard engine has the characteristics of high power, long life and good dynamic performance. It emits 45% lower greenhouse gases than gasoline engines, and also lowers carbon monoxide and hydrocarbon emissions.
C. Diesel is cheaper than gasoline.
D. The torque of the diesel outboard engine is not only larger than that of the gasoline engine of the same displacement, but also the speed range corresponding to the large torque is wider than that of the gasoline engine, that is to say, the low-speed torque of the ship using the diesel outboard engine is larger than that of the gasoline engine of the same displacement. Much easier to start with heavy loads.
E. The viscosity of diesel oil is larger than that of gasoline, which is not easy to evaporate, and its self-ignition temperature is higher than that of gasoline, which is safer
Disadvantages of diesel outboards: The speed is lower than the gasoline outboard (the rated speed of the HC60E four-stroke diesel outboard is 4000r/min), the mass is large (the net weight of the HC60E four-stroke diesel outboard is 150kg), and the manufacturing and maintenance costs are high (because the fuel injection pump and fuel injection The machining accuracy of the machine is required to be high). Large emission of harmful particulate matter. The power is not as high as the displacement of the gasoline engine.

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Post time: Jul-27-2022