Pete Epple Technical Editor
February 15, 2012

Back in the day, you could add a set of aftermarket heads, a bigger cam, and an intake manifold on a pushrod 5.0L and effectively double the power output. Although that sounds impressive, the base motor made a whopping 225 hp. (It’s amazing what was considered powerful in the ’80s and ’90s.) So what effect do heads and cams have on the latest 5.0L?

In 2010, MM&FF got its hands on an ’11 GT to customize for the SEMA show; this also gave us the ability to test parts. Our AMSOIL GT has been a great research and development tool, testing out many “first” products for the Coyote in the past 15 months.

Recently, the idea of adding a set of ported heads and larger aftermarket camshafts came up as a potential story, and the debate started on how the DOHC 5.0-liter would react. One side argues that improved airflow equals increased power. The other side states that Ford did such a great job maximizing the platform’s efficiency, there isn’t much to gain—at least, not when the cost is taken into account. After all, the engine operates above 100-percent volumetric efficiency through most of the rpm band.

We were left with a few questions. How would improved airflow through the already stout heads affect power and torque? What potential was there with the combination of larger cams and the variable cam timing? And how would it all be affected by boost? Well, there’s only one way to find out!

Our trip into the unknown started with a call to Total Engine Airflow (TEA). We have used TEA for some custom porting and cylinder head repair work in the past, and the Tallmadge, Ohio-based company is second to none. With a fresh set of stock castings, TEA went to work designing a CNC program for the Coyote heads.

When it came to camshafts, we had options. With Coyote camshaft technology still developing, we could have used a set of regrind cams, which are just that—stock camshafts reground with smaller base circles on each lobe allowing you to gain increases in lift and duration. The reduction of camshaft base circle usually means the lash adjusters need to be shimmed to make up for the material lost during machining on the camshafts. Our other option was to wait for a set of new billet shafts, and after talking with Comp Cams, we decided to do that.

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