1.6 what is the standard clearance between the intake valve and the exhaust valve of the free ship engine?
When the engine is working, the valve will expand due to the increase of temperature. If there is no gap between the valve and its transmission parts in the cold state or the gap is too small, then 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 order to eliminate this phenomenon, when the engine is assembled in cold state, a certain gap is usually left in the valve and its transmission mechanism to compensate for the expansion of the valve after heating. This clearance is called valve clearance.
The valve clearance must be adjusted correctly to ensure the normal operation of the engine. Excessive clearance: After the intake valve and exhaust valve are opened late, the intake and exhaust time is shortened, and the valve opening height is reduced, which changes the normal valve timing and makes the engine power drop due to insufficient intake and unclean exhaust. In addition, the impact of valve train parts increases and the wear accelerates.
Too small clearance: after the engine works, the parts are heated and expanded, pushing open the valve, which makes the valve not close tightly, causing air leakage, reducing power, causing serious carbon deposition or burns on the sealing surface of the valve, and even the valve hits the piston.
As for the size of the gap, it varies with the designs of different manufacturers. Generally, the intake valve clearance is between 0.2 and 0.25 mm, while the exhaust valve clearance is larger than the intake valve side due to thermal expansion, which is generally between 0.29 and 0.35. After a long period of action and wear, the clearance between the rocker arm of the engine valve and this valve will become larger and larger, so it is necessary to adjust the valve clearance. But not all cars need to adjust the valve clearance. Some cars have automatic oil pressure adjustment, so there is no need to adjust the valve clearance.
Valve clearance can be divided into cold clearance and hot clearance. The hot gap is slightly smaller than the cold gap, and the gap measured in the cold state of the engine is the cold gap. Generally, the cold clearance of intake valve is 0.08 ~ 0. 10 mm, and that of exhaust valve is about 0. 10 ~ 0. 12. The adjustment shall be made in strict accordance with the clearance specified in the manual. The check and adjustment of valve clearance must be carried out when the intake valve and exhaust valve are completely closed. When the piston is at the top dead center of the compression stroke, the intake valve and exhaust valve are completely closed, so it must be at the top dead center when adjusting the valve clearance. The adjustment of valve clearance should be carried out when the engine is cold, and it is strictly prohibited to adjust when the engine is running. Check and adjust the two-cylinder engine cylinder by cylinder.