How High is Too High?

Are the rewards of running a higher-lift cam worth the risks? We hit the dyno with AHP to find out!

- STEVEN RUPP

With engines, bigger is typically better. Well, sort of. Bigger generally means more power, but it can also mean more headaches. More boost will give you more power, but it will also require more octane, unless you want more detonation. More fuel will give you more power as long as you provide more air, and more nitrous will give you more torque, but also entails a lot more risk of things going sideways. The higher the performance, the higher the costs, and we're not just talking about the monetary type.

But what about more lift for your camshaft? If you're a reader of the Internet, you see the idea of adding a "high-lift" cam to your engine mentioned all over the place. It's talked about like it offers free power with no downside. To the average hot rodder, the difference between a 0.626-inch lift cam and a 0.686-inch lift cam seems pretty small, and on paper the 0.060-inch difference is a small number, but in terms of valvetrain movement, it's a lot. To find out more, and test out the gains on a dyno, we got together with the folks over at American Heritage Performance (AHP) to see what benefits there were with a high-lift cam and if the juice is worth the squeeze for the average hot rodder.

01 A cam's "lift" number represents how far the valve will open inside the cylinder. More intake lift means that more air and fuel can enter the cylinder (except with direct injection, where the intake valve brings only air to the party), and, theoretically, more power can be made. On the exhaust side, more lift means more of the spent gasses can be evacuated to make room for a fresh charge of air and fuel to enter the combustion chamber.