How to adjust the valve clearance of multi-cylinder diesel engine

1. When the compression top dead center of 1 cylinder (8 120f cylinder is 5) is found, according to the expression method, for the adjustable valve, use a feeler gauge to block the gap between the end of the valve stem and the head of the valve rocker arm, so that the feeler gauge can move back and forth and plug it gently, otherwise it needs to be adjusted.

2. The specific adjustment method is as follows: firstly, loosen the lock nut on the rocker arm slightly, then turn the adjustment screw with a screwdriver as needed to make the lower (right) clearance smaller and the upper (left) clearance larger until the rocker arm and the valve contact with the thickness gauge and can still move, then use the screwdriver to adjust the screw, tighten the lock nut, move the thickness gauge, and turn the crankshaft for re-inspection until the valve clearance values are all correct.

Extended data:

Because of the complexity of the model, this paper introduces a general method, namely: (double, exhaust, no, intake) method, in which "double" means that both valves of the cylinder can be adjusted, "exhaust" means that only the exhaust valve of the cylinder is adjusted, "no" means that both valves of the cylinder are not adjusted, and "intake" means that only the intake valve is adjusted.

1, the ignition sequence of a four-cylinder engine is: when the cylinder piston is at the top dead center of the compression stroke, the valve adjustment sequence is:

One, three, four, two, double, platoon, no, forward.

Adjust the intake and exhaust valves of the first cylinder, the third cylinder only adjusts the exhaust valve, the fourth cylinder does not adjust the intake and exhaust valves, and the second cylinder only adjusts the intake valve. Such as 462Q q.

2. When the four-cylinder piston is located at the top dead center of the compression stroke, the valve adjustment sequence is as follows:

Four, two, one, three pairs, okay, no, enter.

Adjust the intake and exhaust valves of the fourth cylinder, the second cylinder only adjusts the exhaust valve, the first cylinder does not adjust the intake and exhaust valves, and the third cylinder only adjusts the intake valve.

3. The ignition sequence of a five-cylinder engine is: when the compression stroke of a cylinder is at the top dead center, the valve adjustment sequence is:

One, two, four, five, three pairs, okay, no, enter.

Adjust the intake and exhaust valves of the first cylinder, only the exhaust valves of the second cylinder, but not the intake and exhaust valves of the fourth and fifth cylinders, and only the intake valves of the third cylinder, such as m520 engine.

4. When the piston of a cylinder is located at the top dead center of the exhaust stroke, the valve adjustment sequence is as follows:

Four, five, three, one, two, two, platoon, no, forward.

When the piston of the first cylinder is at the top dead center of the exhaust stroke, adjust the intake and exhaust valves of the fourth and fifth cylinders, the third cylinder only adjusts the exhaust valve, the first cylinder does not adjust the intake and exhaust valves, and the second cylinder only adjusts the intake valve.

5. The ignition sequence of a six-cylinder engine is: when the piston of the first cylinder is at the top dead center of the compression stroke, the valve adjustment sequence is:

One, six, five, four, three, two pairs, okay, no, enter.

Both the intake valve and the exhaust valve of the first cylinder are adjusted; The valves of the sixth and fifth cylinders are adjustable exhaust valves; The intake valve and exhaust valve of the fourth cylinder are not adjusted; While the third and second cylinders only adjust the intake valves, such as universal V6.

6. When the four-cylinder piston is located at the top dead center of the compression stroke, the valve adjustment sequence is as follows:

IV, 32, 1, 65n, double row, none, inch

When the four-cylinder piston is at the top dead center of the compression stroke, adjust the intake valve and exhaust valve of the fourth cylinder; Only the exhaust valves of the third and fourth cylinders are adjusted; The intake valve and exhaust valve of the first cylinder are not adjusted; And only the intake valves of the sixth and fifth cylinders are adjusted.

7. The ignition sequence of an eight-cylinder engine is: when the piston of a cylinder is at the top dead center of the compression stroke, the valve adjustment sequence is:

One, five, four, two, six, three, seven, eight pairs, platoon, no, enter

8. When the six-cylinder piston is located at the top dead center of the compression stroke, the valve adjustment sequence is as follows:

Six, three, seven, eight, one, five, four, two pairs, row, no, input.

The ignition sequence of ten-cylinder engine is:1652,73849.

In this way, we can know the adjustment sequence of valves. The adjustment of valve clearance of vehicle diesel engine should be carried out when the valve is completely closed, and the valve tappet is in the lowest position when the vehicle is cold.

9. Before adjustment, remove the cylinder head cover, pry the crankshaft in the direction of engine rotation, and find the compression top dead center of 1 cylinder. The adjustment methods of valve clearance include memory method, cylinder-by-cylinder adjustment method, expression method and experience method.

Baidu encyclopedia-multi-cylinder diesel engine