How to adjust the diesel valve?

The main adjustment principle is to enter a small row and leave a large row. The following is a detailed introduction:

1. When the engine is working, the valve will expand due to the temperature increase. If there is no gap between the valve and its transmission parts in the cold state or the gap is too small, the thermal expansion of the valve and its transmission parts in the hot state will inevitably lead to the untidy closing of the valve, resulting in air leakage in the compression stroke and power stroke of the engine, thus reducing the power and even making it difficult to start in serious cases;

2. If the valve clearance is not reserved in advance, when the automobile is in a cold state, the valve is in close contact with the cylinder block. When the cylinder block becomes hot, the extension of the valve increases due to thermal expansion, and the valve will damage the cylinder block or the valve itself. Therefore, it is necessary to leave a suitable valve clearance. Reasonable valve clearance is an important prerequisite to ensure the normal and stable operation of the engine;

3. The principle of diesel engine valve adjustment is that the intake valve is cooled with fresh air at 300℃~ 400℃, and the exhaust valve is washed with high-temperature exhaust gas at 600℃~ 800℃. Therefore, the temperature of the exhaust valve is higher than that of the intake valve, and its thermal expansion is greater than that of the intake valve. Therefore, the exhaust valve clearance is generally greater than the intake valve clearance.

Extended data:

Improper adjustment of valve clearance not only affects engine power, fuel consumption and wear, but also noise.

① The valve opening decreases, the intake and exhaust resistance increases, the air intake is insufficient, the power performance decreases, and the exhaust is not smooth.

(2) Increase the impact of the valve train on the valve train, resulting in a large abnormal sound.

③ There will be a "rebound" phenomenon, that is, the valve will jump again after it is seated.

④ There will be "jumping", that is, the rising and falling rules of the valve and the opening and closing of the valve do not meet the original design requirements, which will change the valve timing and affect the power and economy.

References:

Baidu diesel engine valve encyclopedia