From the side valves of the early era, the car valve has evolved into an intricate component that uses precision CNC machining and specialty materials such as steel. Its basic function of opening and closing to allow entry of fresh air and removal of combustion gases remains.
The two types of engine valves, the intake valve and exhaust valve, open and close simultaneously for the efficient performance of the engine. Primarily made from austenitic steel and martensitic steel, these mechanical components contribute immensely to the overall car performance.
This article outlines the basics of the component and emphasizes quality materials, manufacturing processes, and a CNC machining partner like ProleanTech.
What Is The Valve On A Car?
A valve on a car is a mechanical device located in the engine section, and opens and closes to facilitate air entry and exhaust gas expulsion from the engine cylinder. This takes place in an internal combustion engine.
Car engine valve train assembly
Car valves must be designed and manufactured with the extreme conditions of the engine in mind. Efficient performance is also critical to minimize fuel loss and below-par engine performance.
Therefore, the best car valves adhere to requirements for;
- Dimensional accuracy and tight tolerances
- Heat resistance
- Sealing capability
- Durability
- Wear resistance
What Is The Car Valve Called?
Poppet valve and engine valve are alternative names for the car valve. The name “Poppet” comes from the fact that the device makes an up-and-down popping sound as the engine operates.
Parts Of A Car Valve
Parts of the valve include the head, stem, and tip as the main ones. In between these parts are the keeper groove, combustion face, margin, seat face, and fillet.
They are shown in the diagram below:
Car valve parts
What Do Valves Do In An Engine?
The function of a valve in an engine is to allow the entry of an air-fuel mixture to the combustion chamber and the removal of exhaust gases. This is done by the two main types of automobile valves – The Intake valve and the exhaust valve.
Types Of Car Valves
From the main valves, manufacturers have developed different kinds of valves such as poppet valve, rotary valve, and sleeve valve.
Poppet valve – The poppet valve or mushroom valve has a 45-degree seat face and a round stem tip. It is very versatile in operation because it allows for manual, cam, electrical, and pneumatic control.
Poppet valve
Rotary valve – True to its name, the rotary valve uses rotation to open and close the combustion chamber ports.
Sleeve valve – This one uses a sliding or rotational motion to control the entry and exit of air/gases in the engine combustion chamber.
Car Valve Materials
The intake valve in the engine is mostly made from strong and durable materials such as tungsten steel, chrome, and nickel. These materials perform well because the temperatures at the intake are moderate.
However, it is much hotter at the exhaust, hence the materials for exhaust valves can be different. The extreme temperatures require tougher materials like nichrome and silicon-chromium.
Manufacturing A Car Valve
The car valve manufacturing process entails blank preparation, hot forging, friction welding, heat treatment, CNC machining, grinding, surface treatment, and parts assembly.
1.Blank Preparation
The bar or shaft to produce the car valve components is first produced and cut to size. Extrusion and mechanical cutting can come in handy here. At this step, the manufacturer ensures not only that the correct dimensions are achieved but also a suitable grain structure for the valve.
2.Hot Forging
The part is then subjected to hot forging, which involves heating the material to a high temperature and compressing it into a mold. After this, the part undergoes further processing.
3.Friction Welding
Friction welding
Friction welding is an effective joining method for a valve comprising multiple metallic components. High-speed relative motion between the head and stem components to create localized heat is a perfect example of the application of this technique.
4.Heat Treatment
Heat treatment ensures the car valve parts maintain their properties and dimensions despite the high temperatures and demanding engine performance requirements.
5.CNC Machining
CNC (Computer Numerical Control) machining processes – drilling, milling, and turning – are instrumental in the engine valve manufacturing process. CNC turning generates the groove, stem, and face angles.
Milling is effective at creating keyways, undercuts, sealing surfaces, and complex undercuts not possible with CNC turning.
Manufacturers use CNC drilling for center holes, oil drain holes, and cooling channels (found in some customized engine valves).
6.Grinding
Grinding the CNC-machined engine valve components helps achieve tighter dimensional accuracy and a smoother surface.
7.Surface Treatment
Valve surface treatments – coating, mechanical, and Surface hardening – enhance durability and performance.
Car Valve Problems, Maintenance, And Replacement
No matter the design or material used, car valves are like other engine components and therefore prone to degeneration over time. It is important to identify common valve problems, perform regular maintenance, and replace parts promptly.
How Do I Know If My Car Valve Is Bad?
Valve problems show in the form of loss in engine power, blue smoke, and noises from the engine.
How Much Does It Cost To Replace A Car Valve?
The cost to replace a car valve depends on several factors, including car model, the labor costs based on region, availability of parts, and sometimes, the speed of the replacement process.
Conclusion
Car valves are undoubtedly at the center of combustion engine operation, making them a critical consideration for every car dealer, supplier, manufacturer, or mechanic. Learning about auto engine parts and functions like these is crucial for successful sourcing, recommendation, and use.
With flawless CNC Machining Services and related solutions, ProleanTech stands out as a solution provider of car valves.
