Camshafts are one of the most confusing components in an internal combustion engine. What makes those lumpy bumpsticks even more confounding is the sheer number of grinds available, and then multiply that by flat-tappet hydraulic, hydraulic roller, and mechanical roller. With all those choices, how do you go about choosing a cam? While you could use the dartboard approach, in this age of computer simulators there's just no excuse for not arming yourself with the right information. That's what we're going to dive into here. To play out our dartboard analogy, consider that once you've read this story, that ancient finned dart has just become a laser-guided missile that will home right in on your next cam selection.
We chose three cams with almost...
We chose three cams with almost identical duration numbers to use as our test mules to compare a hydraulic flat tappet against a hydraulic roller against a mechanical roller cam. The results were surprising.
It seems there is plenty of misinformation when it comes to comparing and contrasting a hydraulic flat-tappet cam with a hydraulic or mechanical roller. All three offer different valve lift potential, yet there should be a way to compare them on a level playing field. We huddled up with Comp Cams' chief cam designer, Billy Godbold, and came up with a camshaft from each of those different follower families that all share a very close kinship with duration at 0.050 inch, so that's what we chose as our common denominator. Now right away, you're going to look at the cam specs box and think we're off our rocker arms because the numbers don't match up. See, that's where it gets complicated. You're gonna have to read all the solid tech stuff to understand what we're doing here. Don't skip over the details or you'll miss something important. And while you're at it, eat your vegetables too.