Working with the experts at COMP Cams, the crew at Speed Secrets is on a mission to demonstrate the power gains of a cam swap in a 2-valve 4.6-liter modular Ford engine. Not only will you see the power gains from the swap, but the engine is thrown on the dyno both naturally aspirated, and under boost. Why show both? Because a cam swap is worth even more power when it’s combined with boost.
Your naturally aspirated engine is already operating under atmospheric pressure of 14.7 PSI, if you add another 14.7 PSI to that engine, you can, in theory, double the power output of that engine – so a 300-horsepower engine becomes a 600-horsepower. If you do this and also swap the cam, the power gains from camshaft upgrade will also double.
With some upgrades, but a stock cam, the test engine has a baseline dyno of 346-horsepower and 363 lbs/ft of torque. A set of XE274H COMP cams was chosen for this test. These cams offer a .500 lift, 236/340 duration, and a 114 LSA. With just the cam alone, the horsepower jumped to 377-horsepower and 379 lbs/ft of torque.
Now it’s time to see what these cams are worth under boost, and a Vortech supercharger will provide just that. Run with the stock cams, the engine is good for 551-horsepower and 505 lbs/ft of torque. With the XE274H cams, the power jumped to 624-horsepower and 547 lbs/ft of torque – making the cam swap worth an extra 73-horsepower and 42 lbs/ft.