What are the advantages and disadvantages of a two-stroke engine?

Advantages and disadvantages of two-stroke engine;

1. Advantages:

(1) It explodes 1 time per revolution, so the rotation is very stable.

(2) No valves are needed, few parts are needed, the maintenance is convenient, and the price is cheap.

(3) The reciprocating motion has small inertia force, small vibration and low noise.

(4) Compared with the four-stroke engine, it has higher power at the same speed.

(5) Compared with four strokes, it is more explosive. Therefore, under the same volume, if the average effective pressure is the same, the power is twice (actually 1.7).

2. Disadvantages:

(1) The intake and exhaust process takes a short time, so the fuel loss is large.

(2) There are air holes on one side of the cylinder wall, where the piston ring is easy to wear.

(3) Because the exhaust port is on the cylinder, it is easy to overheat.

(4) Slow and unstable.

(5) Consume more lubricating oil.

Extended data

Working principle:

There are three holes in the engine block, namely, air inlet, air outlet and air exchange hole, which are closed by the piston within a certain period of time. Its working cycle includes two strokes:

1. the first stroke: the piston moves upward from the bottom dead center, and after the three air holes are closed at the same time, the mixed gas entering the cylinder is compressed; When the air intake is exposed, the combustible mixture flows into the crankcase.

2. The second stroke: When the piston is compressed to near the top dead center, the spark plug ignites the combustible mixture, and the gas expands to push the piston to move down to do work. At this time, the air inlet is closed and the combustible mixture sealed in the crankcase is compressed; When the piston approaches the bottom dead center, the exhaust hole opens and the exhaust gas rushes out; Then, the air exchange hole is opened, and the pre-compressed combustible mixture rushes into the cylinder to drive away the exhaust gas and carry out the air exchange process.

Refer to Baidu Encyclopedia-Two-stroke Engine