Taken from the Comp Cams catalog,...
Taken from the Comp Cams catalog, this diagram extols the various advantages of beehive valvesprings and ovate wire.
HPP: How does the overall valvetrain weight affect performance/rpm?
TG: Weight on the valve side of the valvetrain should include the lock, retainer, valve, and valvespring. In most cases, a lighter valvetrain allows for increased valve control at higher engine speed, and it also reduces overall valvetrain mass, which can let the engine spin higher. Pontiac engines tend to have a heavy valvetrain, and that can limit maximum rpm. One way Pontiac engine builders can increase that speed is to use a valve with a smaller stem and thinner head, significantly lightening it. The next constraint would then be the amount of lift available.
HPP: How are valvesprings cooled?
TG: When a spring is compressed, the metal's grain boundaries move around, causing friction inside the metal itself. This friction results in an enormous amount of heat generated during normal operation; engine oil is then used to cool the springs. If they're not cooled properly, their effectiveness diminishes, and in some applications, can actually break.
HPP: Does fatigue occur and is it predictable?
TG: By definition, fatigue is the reduction of a spring's effectiveness over time, and it's a function of material manufacturing techniques and application. It occurs in one or both of two ways-first, with load loss, and second, with complete failure. Predictability is next to impossible because of these factors.
Many hobbyists are familiar...
Many hobbyists are familiar with some of the terminology associated with an engine's valvesprings, but that's only a portion of what valvetrain engineers must consider when designing them for specific applications. This diagram reveals some others.
HPP: Which Comp Cams valvesprings are commonly suggested for Pontiac applications?
TG: Our engine-builder salesmen tell me that our beehive Nos. 26986 and 26125 are popular choices for many street-driven Pontiacs that utilize either type of flat-tappet camshaft or a hydraulic roller. No. 978 is a cylindrical dual-spring set that's popular in engines that see higher speeds. We suggest calling our technical support staff to discuss specific applications, however.
HPP: What do you see in the future?
TG: As hobbyists learn more about beehive-type valvesprings and realize that such technology is here to stay, they are becoming more comfortable with the idea of running a single beehive spring in performance applications where only a cylindrical dual-spring was once suitable. As beehive technology grows and these springs are utilized in more applications, we continue to see its abilities and limitations and can suggest applications where they might not be suitable.
In addition to valvesprings, we've developed a line of new tool-steel retainers for both our beehive springs and traditional cylindrical units. These retainers are much lighter and stronger than our typical steel units. In fact, we're suggesting them in applications where titanium retainers were once the only choice. While titanium units are still a necessity in extreme applications, the tool-steel units are much stronger and weigh only 2-3 grams more for a fraction of the cost.
Conclusion
Comp Cams is just one company familiar with modern valvespring technology, and there's little doubt that the engineers of competitors are focusing on ways to improve components in the same manner.
No matter the case, valvespring technology is rapidly changing, and the comments Griffin shared point us toward the future. So the next time you remove your Pontiac's valve covers, take a moment to look at its valvesprings and think about the stressful conditions in which they operate. You might have a newfound respect not only for those components, but the people who design them.