The difference between marine diesel engine and vehicle diesel engine

What is the difference between a marine diesel engine and a vehicle diesel engine?

1. Different compression ratios:

The compression ratio is the ratio of the gas volume in the cylinder before and after compression. The engine converts thermal energy into mechanical energy by mixing air and fuel to drive equipment. Because diesel has no knock, the compression ratio is higher than that of gasoline (generally, gasoline engine 8~10:1, diesel engine 16~20:1), so the efficiency is also high.

2. The crankshaft speed is different:

Gasoline engine is generally 5000r/m, diesel engine 3000r/m;

Compared with diesel engines, gasoline engines have lower power, stable operation, and lower noise; light weight and small volume; the distance between the journal and the bearing bush is small (generally, gasoline engine 0.05mm, diesel engine 0.2mm).

3. Different emissions:

Gasoline engine emissions are mainly HC, CO, NOX, diesel engine is mainly NOX, PM, HC, CO.

Compared with gasoline engines, the HC and CO emissions of diesel engines are quite low, generally only a few tenths of those of gasoline engines. The NOX emissions of diesel engines are also comparable to those of gasoline engines, but the particulate emissions of diesel engines are about 30 to 80 times that of gasoline engines.