Camshaft Comparison - Cam Tech

Roller-Rocker TestThere was a time when aluminum roller rockers were a status symbol of only the most elite road race or drag race engine. Today, you have to look for a reason not to run a set, especially when you read this test that originally ran in the January '01 issue. Here, the guys at Westech bolted a mild 350ci small-block Chevy to the dyno equipped with a Comp Cams Xtreme Energy 268 hydraulic flat-tappet cam, stock stamped-steel rockers, a set of TFS 23-degree aluminum heads with 2.02/1.60-inch valves, an Edelbrock Performer RPM intake, a Barry Grant 750-cfm Speed Demon carb, and a set of 151/48-inch headers feeding into a 211/42-inch Flowmaster exhaust.

The test was a simple comparison of stock stamped-steel 1.5:1 ratio rockers to a set of Comp Cams Pro Magnum steel 1.5:1 and 1.6:1 rockers and a 1.65:1 ratio Comp High Energy aluminum rockers. The following chart reveals the power increases that generally track right along with the ratio. Where else can you bolt on something simple like a set of rocker arms in about an hour that will add an average of 15 lb-ft of torque and 13 hp? Granted, not all engines will respond as this one did. Basically, a bone-stock set of heads would probably not have gained as much as this combination. Clearly, the better cylinder heads that flowed 250 cfm at 0.500-inch lift offer proof as to why this test was successful. That's probably the lesson here-that stock heads will not benefit as much from more lift compared to ported or aftermarket heads. This test does point out the power of a well-matched package of cam and valvetrain.