What are the functions of valve guides?
2 Answers
Valve guides serve the following purposes: 1. The valve guide provides guidance for the movement of the valve, ensuring the valve moves in a reciprocating linear motion, enabling proper contact between the valve and valve seat, and transferring heat from the valve stem to the cylinder head. 2. The lower part of the valve guide extends into the intake and exhaust ports. To minimize airflow resistance, the extended end is designed with a conical outer shape. A clearance of 0.05~0.12mm is maintained between the valve guide and valve stem, allowing the valve stem to move freely within the guide. 3. Valve guides operate at relatively high temperatures, approximately 200°C. During valve stem movement within the guide, lubrication is solely provided by oil splashed from the valve train, making them prone to wear.
The valve guide plays a crucial role in the engine. Without it, the car won't run smoothly. Having driven for over a decade, I always inspect this small component during maintenance. It precisely guides the valve's up-and-down movement, preventing the valve stem from wobbling or excessive friction, which could lead to wear or increased noise. Additionally, it helps lubricate the valve stem, reducing friction heat buildup and protecting the valve from burning out. Delving deeper, the valve guide also aids in sealing the combustion chamber, preventing air leaks that could affect performance and ensuring smooth intake and exhaust. Neglecting maintenance can accelerate wear, increasing fuel consumption or even causing engine damage. I believe regular valve guide inspections save money and hassle, extending your beloved car's lifespan.
