What are the methods for adjusting valve clearance?
1 Answers
Adjusting valve clearance involves the following steps: 1. Based on the firing order of the cylinders, determine when a particular piston is at the top dead center of the compression stroke, then adjust the intake and exhaust valve clearances for that cylinder; 2. After completing the adjustment, rotate the crankshaft and proceed to adjust the valve clearances for the remaining cylinders in the same manner. Valve clearance is categorized into cold engine values and hot engine values, and measurements should be taken under the conditions specified for the vehicle. When the engine is running, the valves expand due to increased temperature. If there is no clearance or insufficient clearance between the valves and their transmission components when cold, thermal expansion during operation will cause the valves to not close properly, leading to leakage during the compression and power strokes. This results in reduced power output and, in severe cases, difficulty starting. To prevent this, a certain clearance is typically maintained between the valves and their transmission components when the engine is assembled cold, to compensate for thermal expansion. This clearance is known as valve clearance.