Top 5 Camshaft Mistakes from Nolan Jamora, Isky Racing Cams
Overcamming an engine: Most guys just don't have the experience to choose best cam and almost always overcam the engine. Then they call and say they have no bottom end or can't get it to idle and that it's the cam's fault. They should have called first.
Wrong Combination: This happens a lot. A guy buys the same heads his buddy has and the manifold he read about in an article and is running the carb his engine came with and has no idea what his stock converter stalls at yet he puts it all together and thinks it will run great. Now you have a guy with a 600-cfm carb, a single-plane manifold, heads designed for 8,500 rpm, a cam that runs 3,000-7,000 rpm, and a 1,800-stall converter. That's just bad news and a waste of time and money. You have to have all your parts working together and all able to work in the same rpm range as the cam.
Wrong LSA: When you get a good combo going and you order the cam, you have to be aware of the right LSA for your cam. Even if you've picked the right cam for your combo and rpm range, the wrong LSA could still cause problems. If you have two cams with the same lift and duration but one has a 106 LSA and the other a 112, the one with a 106 will have better bottom end and midrange and rough idle but less top end, and the other will have better top end and a smoother idle.
Buying a Cam for Your Next Engine Now: I have guys call all the time for a cam recommendation and tell me what their combo is. Then just after the guy places the order he will say, "So for now I'm gonna put this roller cam in with my Performer manifold and stock heads for a while 'til I can afford the better heads, manifold, and carb. That'll be cool, right? Be smart and buy a cam that works with what you have now, not what you want to have down the road.
Wrong Type of Cam: The choice between hydraulic, solid flat-tappet, hydraulic roller, and solid roller is very important. If your engine comes hydraulic and you only want a little increase in performance, stay hydraulic. If you want to pick up a few thousand rpm and not have to check lash, run a hydraulic roller. If you want the sound and rough idle for a street/strip combo and don't mind adjusting the lash, run a solid flat-tappet. If you are racing, it's almost always best to go full solid roller. Get with a cam tech and go over the setup to pick the right type of cam with the right specs.
When GM created the LS engine family, it increased the cam core size from the traditional 1.868 inches (approximately 47.5 mm) to 2.165 inches, or 55 mm. Lunati has taken this technology a step further by creating an even bigger 60mm core. Why is bigger better? According to James Humphrey, the super-sized cam core was created for use in the LSX block and the World Products Warhawk block. "The LSX can run a 4.250x4.500-inch bore and stroke for 500-plus cubic inches, and it's capable of 2,500 hp," he explains. "The bigger base circle gives better valvetrain dynamics and higher rpm," he continues. "We can be more aggressive with our profiles and maintain stability, since there is little deflection." And while Humphrey admits that we'll "eventually" see street-oriented cores produced, this is definitely a race piece for now.
Crane Cams has been utilizing quick-lift lobe design for as long as the technology has been available--this example is a Powermax Z-Cam hydraulic roller 'stick for a big-block. Crane's roller rocker arms, the Energizer and especially the Gold rockers, have been enthusiast favorites for years and were used in the last of the traditional small-blocks, the 330-horse LT4. The valvespring on the left has been treated with Crane's Mikronite process. It's not a plating or a coating, but rather a surface treatment that reduces friction between mating surfaces, increases metal toughness, and removes minute stress risers created during manufacturing.