How to Adjust the Valve Clearance of Diesel Engine

Cylinder-by-cylinder adjustment method, that is, after determining the compression top dead center position of a cylinder piston according to the ignition sequence of the cylinder, the gap between the intake valve and the exhaust valve of the cylinder can be adjusted; After adjustment, turn the crankshaft and gradually adjust the valve clearance of other cylinders according to this method.

Different models have different valve clearances. Generally, the intake valve is between 0.25 mm and 0.35 mm, and the exhaust valve is between 0.30 mm and 0.45 mm, and the exhaust valve clearance of some highly intensified and high thermal efficiency engines can reach1.0 mm. ..

Main hazards:

Excessive valve clearance will cause impact noise between valve transmission parts and between valve and valve seat, accelerate wear, shorten valve opening duration, reduce cylinder inflation coefficient and exhaust incompletely; If the valve clearance is too small, the engine can't close the valve tightly in hot state, resulting in air leakage, power reduction and even burning out the valve.

The valve clearance changes due to the wear of the transmission chain of the valve train, so it is necessary to adjust the valve regularly. Different engine valve clearance adjustment methods are different. Generally, there are two methods: adjusting screws and adjusting gaskets. The sequence of valve adjustment is also related to the working sequence of the engine. Nowadays, most automobile engines use hydraulic tappets, whose length can be automatically changed and valve clearance can be automatically eliminated.