Determination method of valve clearance of diesel engine 190( 12 cylinder)

Before adjusting the valve clearance, it is necessary to determine the clearance value of the intake and exhaust valves of the diesel engine (different models have different requirements, and the 2000 series is 0.43±0.05mm and 0.48±0.05mm；; 0.4 0.05 mm, 0.5 0.05 mm and so on. 3000 and 4000 series please refer to the manual), and then adjust according to the following steps:

1. Turn the crankshaft (slightly loosen the cylinder head bleeder plug for quick rotation) so that the pointer points to the flywheel scale "0" position. At this time, the piston of the first cylinder in the left row is at the top dead center.

2. Identify the working stroke state of the first cylinder. Method 1: Turn the crankshaft slightly. If the intake and exhaust valves of the cylinder are fixed and there is exhaust sound at the exhaust plug, the first cylinder is in the working stroke state; If both the intake valve and the exhaust valve move, the first cylinder is in an intake stroke state. Method 2: Twist the upper end of the tappet by hand. If both tappets can rotate easily, the first cylinder is in the working stroke state; If both tappets cannot rotate, the first cylinder is in the intake stroke state.

According to the working state of the first cylinder, it can be adjusted according to the "adjustable valve" listed in table 1. After adjustment, turn the crankshaft once (that is, turn it 360 so that the pointer still points to the "0" position), and then adjust it according to the corresponding intake and exhaust valves listed in another row of the table.

Or according to the ignition sequence: 1-8-5-10-3-7-6-11-2-9-4-12, adjust one cylinder at the same time from1cylinder.

3. Check the valve clearance. The method is as follows: use a feeler gauge to insert the gap a between the rocker arm adjusting screw 6 and the top of the rocker arm transverse bridge 4 (see figure 1). When the feeler gauge can be inserted by hand and can pass smoothly, the thickness of the feeler gauge is the measured valve clearance value.

If the measured valve clearance exceeds the specified value, a feeler gauge (or special feeler gauge) should be selected according to the specified clearance value by loosening the lock nut and inserted between the rocker arm adjusting screw and the cross bridge for adjustment. Turn the adjusting screw down with a screwdriver so that the screw gently presses the feeler gauge, and then turn the tappet by hand. When the tappet can rotate and feel astringent, fix the position of the adjusting screw with a screwdriver and tighten the lock nut.