Valve Springs are an essential component for the efficient performance of your engine. Proper selection of valve spring is an important factor for the engine to reach its full potential.
We use alloys such as high tensile chrome silicon, chrome vanadium alloy and other superalloys for the manufacturing of valve springs as they have higher performance and durability. Our engineers have experience and possess in-depth knowledge of the design and manufacturing of valve springs.
Key factors we consider for valve spring design and manufacturing are:
- Higher flow rates
- Durability
- Finishing
- Tolerance of environmental conditions
Coiling Technologies, Inc., incorporates the latest design technologies, equipment, and methodology for providing a higher quality product than our competitors' in the market. To know more about our services, please contact us.
Chrome Silicon Valve Springs FAQs
What does a valve spring do and why does its selection matter?
A valve spring closes the valve and keeps the valve train in contact with the cam through the entire lift event. If it cannot control the valve at the engine's operating speed, the follower separates from the cam profile, valve motion stops matching the cam, power drops, and the valve can contact the piston. CTI's page makes the point directly, that proper valve spring selection is an important factor in the engine reaching its full potential. The design problem is holding enough seat and open load to control the valve train without adding unnecessary friction, heat, and stress.
Why is chrome silicon the standard valve spring material?
Chrome silicon is a high tensile carbon alloy spring steel, and it holds up under the two conditions that eliminate cheaper grades: high stress and elevated temperature. Silicon raises tempering resistance, so the material keeps its strength and resists relaxation at valve spring operating temperature, where music wire and hard drawn grades lose load. Chromium adds hardenability and strength. CTI also uses chrome vanadium alloy and superalloys for valve spring work, selected for higher performance and durability. Chrome vanadium is generally favored where impact and shock loading form part of the duty cycle.
Why does stress relaxation matter more than initial load in a valve spring?
A valve spring gets qualified on its installed load, then spends its service life losing some of it. Relaxation is time, temperature, and stress dependent creep, and it appears as reduced free length and reduced seat load rather than as a broken part. Seat load is what controls valve closing and sealing, so a spring that has relaxed ten percent can pass a visual inspection and still leak or float. That is why tempering resistance, design stress level, and operating temperature matter more to real service life than the load measured on day one.
How does cycle life get designed into a valve spring?
Count the cycles first. A valve spring in continuous engine service accumulates cycles into the hundreds of millions, so design stress has to sit below the fatigue limit rather than below yield. Fatigue is driven by the stress range between installed height and full lift height, not by peak stress alone, so reducing lift stress often extends life more than adding material. Surface condition governs the rest, because almost every valve spring fatigue failure initiates at the wire surface. Shot peening, which CTI performs in house, puts that surface into residual compression and delays crack initiation.
What operating conditions should I specify for a valve spring quote?
Give the assembly envelope first, meaning installed height, height at full lift, outside and inside diameter limits, and any spring pocket or retainer constraints. Then give the loads at both heights, or the required rate with one load point. Then give operating temperature, maximum engine or actuation speed, required cycle life, and the media the spring sits in, since oil, fuel, and process gas each affect material choice. CTI's page lists flow rate, durability, finishing, and tolerance of environmental conditions as the design factors it works from.
Can CTI reproduce a valve spring from a sample if I have no drawing?
Yes. CTI can reverse engineer from a physical sample, and any load or dimensional data you have shortens the process. A used valve spring needs care rather than straight copying, because a spring pulled from service has usually lost free length and load, so measuring it and reproducing those numbers reproduces a worn part. Provide the target loads at installed and open height if you have them. The engineering team can also design from performance requirements alone, which is the better route when the original spring was the limiting component in the assembly.
