Both the gasoline engine and the piston of the diesel engine are quite different in the main structure. Generally, the piston of the gasoline engine is relatively small in diameter, relatively small in wall thickness, and relatively light in weight. The piston diameter of the diesel engine is relatively large, the wall thickness is relatively thick, and the weight is relatively heavy. The shape of the piston is quite different.
The biggest difference between gasoline engine and diesel engine is ignition mode and intake air: the gasoline engine enters the cylinder is the combustible gas mixed with oil and gas, the diesel engine is pure air; the gasoline engine is ignited by the spark plug, and the diesel engine is injected after the compressed air reaches the diesel self-ignition temperature. The hole injects diesel fuel, and the diesel is self-igniting due to the high temperature in the cylinder at this time.
To make the difference, it may be at most in the skirt of the piston, because most diesel engines have longer piston strokes than gasoline engines, and may have a special shape in the skirt that matches the flywheel movement, but not all diesel engines.
First take the 2-valve gasoline engine and the diesel engine’s piston ratio: the difference is at the top of the piston. The gasoline engine piston is flat, and the diesel engine piston has a combustion chamber at the top. This is the biggest difference. Then take the multi-valve gasoline engine piston and diesel piston comparison: the top has Combustion chamber. But the gasoline engine is relatively simple. The distance between the piston ring groove is larger than that of the gasoline engine. The oil ring groove diesel engine has holes. The gasoline engine does not. In general, there is a big difference.