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The key profile features of a camshaft can be found in the camshaft profile section of the COMP Cams catalog. By reviewing the duration specs for your potential camshaft at 0.050-inch lift and again at 0.200-inch lift, a comparison of the relative speed of one lobe to the next can be determined. Currently, Beehive springs from Comp Cams are available for camshafts measuring up to 0.750-inch lift.
Resonance
If something sounds good, it’s worth investigating, except where valve springs are concerned. Sound is the key. While it’s great for musical instruments, valve train sound --
or more correctly, resonance -- is generally destructive. As with sound waves, resonance "frequencies" cause parts to pull apart. When you figure the speed with which your engine’s parts move (at 9000 rpm, your valves open and close 75 times per second) the valve spring surges like a cylinder full of water.
Beehive springs are designed with a more optimum natural frequency, which is a good thing. At COMP Cams they can actually move the frequency of the spring material up to such a high rpm level as to not be of a concern with your engine).
 A graphic display of the difference in weight between a standard cylindrical spring and a Beehive spring. Remember however, Beehive springs are not appropriate for all valve train applications. |
Resonance can also be dampened by installing springs that, when compressed, are closer to coil bind. Setting up a spring to run closer to coil bind (0.040 to 0.050-inch over max static valve lift) can help control the valve better. To this point, shimming up a shorter spring can actually be a performance improvement over using another spring, which has a higher installed height.
"The height of a spring before it is installed has no real significance as to its performance," notes Griffin. "The most important determiner is the installed height. You never want to achieve coil bind as it can have devastating affects on the engine. But a shorter spring shimmed to the proper height will help the efficiency of your engine. It is true that nearing coil bind there are additional frictional losses, but I’d trade that for increased spring stability any day because the gains in control outweigh the losses in frictional horsepower."
