How Does The Engine Adjust The Valves?

1. Cylinder by cylinder adjustment method
According to the ignition sequence of the cylinder, the clearance between the inlet and exhaust valves of the cylinder can be adjusted after the piston of the cylinder is determined at the top dead center of compression; After adjustment, rotate the crankshaft, and gradually adjust the valve clearance of other cylinders according to this method.
2. Adopt twice adjustment method
Crank the crankshaft so that the piston of the first cylinder is at the top dead center of compression, and the flywheel mark is aligned with the marking line of the inspection hole. At this time, the valves 1, 2, 4, 5, 8, and 9 can be adjusted (referring to the engine valves arranged from front to back); Then rotate the crankshaft for one circle to make the six cylinder piston at TDC of the compression stroke, and then adjust 3, 6, 7 and 10 "plus two" (i.e. 11 and 12) valves, which is actually a memory adjustment. During adjustment, tighten the adjusting screw, insert a feeler gauge between the valve stem end and the rocker arm, and pull it back and forth. It is appropriate to feel slight resistance, and then recheck until it is appropriate.
The cylinder by cylinder method needs to rotate the crankshaft more times and takes more time to check and adjust. However, for engines with severe wear, the cylinder by cylinder method is more accurate in checking and adjusting the valve clearance. Adjusting the valve clearance twice saves time and effort, but it is difficult for maintenance personnel to remember different adjustable valve sequence numbers for different models because of the complexity of the models.