Q&A:James Humphrey, Lunati
CHP: What was the genesis of the Voodoo line?
James Humphrey: Lunati has made excellent cams, but in today's marketplace, if you stay with the same thing, you don't last.
CHP: So what's different about the Voodoo cams?
JH: The lobe acceleration rate, the increased area under the curve, and our unique approach to duration at 0.050. We've also paid attention to lobe separation. Wider separation makes for a wider powerband. The Voodoo cams have a 110- and 112-degree LSA, which means they'll work with aftermarket four-barrels and OEM computers.
CHP: What did you mean about your approach to duration at 0.050 inch lift?
JH: With the advent of improved heads and valvesprings, we can get away with a lot more than we used to. That means bigger, better profiles. You get more air throughout the range with a quality head.
CHP: Have you introduced any other new pieces?
JH: We've added beehive springs and a line of pacalloy springs, which are extremely high quality yet affordable. We've also added retainers and locks as well as new solid lifters.
CHP: What trends are you seeing in what the public wants?
JH: I still see a lot of hydraulic flat-tappet action, but the trend is leaning more and more toward hydraulic rollers. You don't have to rely on maintenance or rotation but can still get fairly aggressive.
Crower has camshafts for just about any application, though we think it's fair to say much of its clientele leans toward the hot street and racing side of the game. The cam shown is a solid roller 280R piece intended for the former, along with some of Crower's Severe-Duty cutaway lifters and titanium retainers. The company makes aluminum stud-mount rockers, of course, and its shaft-mount systems are available in aluminum or stainless steel, in a variety of offsets.
"One of the absolute killers to high-end horsepower is lack of valvetrain stiffness, Comp's Billy Godbold tells us. "You lose stability, and even if you can control the valve with its spring, things start to bend." As a result, duration--and therefore high-rpm horsepower--is lost. When should you look into using a stud girdle? Godbold actually surprised us with his answer. "If you're going racing with stud-mounted rocker arms, you should use one, but if you have the right cam, you should be running fairly close to its limit speed; you should be on its dynamic threshold." In other words, when you've already upgraded everything else in your valvetrain and are running near its limit, it's time to consider a stud girdle. "If you're after that last 5-10 hp, you should look into it," says Godbold. "It lets you lock all the studs together, and if you have a stiffer upper valvetrain you have more duration."