There are many parts inside an engine that perform very important functions for its correct operation. One of these pieces, we find it in the cylinder head of the engine and we call it valve seal. Each valve inside the cylinder head carries a valve stem seal and they are a critical part of your engine’s valve train.
here we will learn what is valve seal and you will also learn about some related aspects, which are very important for every car owner to know.
What is the valve seal?
The valve seal is the one controls valve stem lubrication as it slides in the valve guide and minimizes engine emissions.
Too little oil causes stem and guide wear. Too much oil increases oil consumption and can also cause carbon build-up, decreased efficiency and degradation of the catalytic converter. This buildup can also lead to valve seat damage and premature valve wear.
The more and more strict emissions regulations make it imperative that oil does not enter the combustion chamber if we want to pass the ITV in a favorable way.
How does a valve seal work?
valve seals prevent oil from contaminating the fuel-air mixture in the engine’s combustion chamber, where it can cause severe damage to various components. Also prevent the oil in the cylinder head and the rest of the engine from being contaminated by intake and exhaust gases.
The valve stem has an inner diameter that fits over the valve stem and an outer diameter that fits over the valve guide. This forms a secure seal between crankcase and combustion chamber, preventing contamination and leaks.
What material is a valve seal made of?
Valve seals are made from a variety of materials, which include nylon, rubber, steel and synthetic rubber. Sometimes these materials are combined to make a single sophisticated design. The biggest difference between the three types of synthetic rubber seals is their resistance to heat.
valve seals they usually have small springs that allow them to fit securely over the stock.
What are the basic designs of a valve seal?
There are two basic valve stem designs: deflector seals and positive seals:
- Baffle seals, also known as umbrella seals, divert oil away from the valve stem to prevent over-lubrication.
- Positive seals are attached to the valve guide boss and work like a squeegee, metering and cleaning oil as it passes through the seal.
What causes a valve seal to fail?
There are several factors that can cause a valve seal to fail and degrade over time. These are generally the most common causes:
- Due to infrequent oil and filter changes.
- Due to incorrect installation.
You may notice a lot of smoke coming out of the tailpipe if you have a bad valve stem seal.
