What adjustment is made to hydraulic lifters?

Hydraulic lifters are designed to maintain a constant clearance between the valve and the rocker arm by automatically adjusting to changes in thermal expansion and wear. The correct adjustment involves setting them to zero lash, which means ensuring that there is no gap between the lifter and the pushrod or rocker arm when the valve is closed. However, after reaching this point, an additional specific number of turns is required to ensure proper operation. This additional turn accounts for the hydraulic action and ensures that the lifter can adequately maintain its function under various engine conditions.

Setting the lifters correctly is vital for ensuring that the engine runs smoothly and efficiently. Adjusting them to zero lash without the extra turns could lead to the lifters being too tight or not functioning properly, potentially causing engine noise, premature wear, or even failure. Therefore, it is essential for technicians to follow a specific adjustment procedure to guarantee optimal engine performance.