Valve springs are one of the most critical and most overlooked components in an engine. Valve springs play an important role in controlling the breathing in a diesel engine. The valves open mechanically by a camshaft, and are closed by the tension of the valve springs. When considering that a typical diesel engine valve is opening and closing hundreds of millions of times during its life cycle, it is imperative that valve springs be replaced during the next overhaul to attain the best performance from your engine. Improper selection of the valve spring is one of the most common causes of engine failure. Your CTP salesperson can ensure that you obtain the proper valve springs for your engine. CTP has the most complete selection of high quality valvetrain components in the industry.