It seems that all popular Mopar engine styles have a loyal following of enthusiasts, each claiming the prowess of their favorite Chrysler corporation powerplant, but none more vocal than those who love the small-block Mopar. And while we generally write off the small-block lover's claims of Slant-Six economy and big-block torque as somewhat boastful, the entries in the 2010 AMSOIL/Mopar Muscle Engine Challenge have made us believers in these small, but potent V-8s.

This year's contest featured Chrysler's most widely produced V-8 engine, the LA series small-block. The engine builders all had to use the same cylinder heads, the high-flowing RHS/Indy X cast-iron units, but otherwise pretty much anything aside from one-off exotic pieces was fair game. To determine the winner, the 2010 challenge relied on one of the oldest standards of hot-rodding-horsepower per cubic inch. With no limit on displacement, this year's builders brought engines ranging from just over 273 cubic inches, to Mid America's 408-inch powerhouse.

To determine a winner of the engine challenge, we spent a week at Comp Cams' Memphis, Tennessee, dyno facility where each engine builder was given the chance to first qualify his or her engine by making three pulls during a 45-minute timed qualifying period, then making a minimum of three judged dyno pulls during another 45-minute timed period. The numbers from the best judged pull were then factored into each engine's displacement to determine the winner. This month we'll show you what it took for Mid America Racing Engines and MRL Performance to place third and forth respectively in the 2010 AMSOIL/Mopar Muscle Engine Challenge, and be sure to log onto moparmusclemagazine.com to see videos of each engine on the dyno.

Mid America Racing Engines
Located in Washington, Iowa, Mid America Racing Engines has competed in all but one of our dyno competitions. This year their entry was the largest engine of the contest, at 408 cubic inches. Once bolted to the dyno at Comp, the small-block fired immediately, sounding throaty and crisp. It was obvious by the sound that this engine was going to make power, so everyone attending gathered near the dyno cell while engine builder David Bruns made his pulls. Using standard engine tuning techniques, the Mid America engine netted more power with each pull, eventually making a best judged pull of 580.5 horsepower for a factor of 1.422 horsepower per cubic inch.

Achieving nearly 600 horsepower from a 408 cubic-inch small-block running on Rockett Brand 93 octane unleaded is no small feat, and David Bruns used a carefully selected combination to accomplish the task. Starting with a 1972 dated factory 360 block, an Eagle forged four-inch stroke crankshaft was added along with Scat connecting rods and CP forged pistons. A Melling oil pump and Moroso pan were combined with a Milodon windage tray to ensure proper oiling. A Cam Motion Camshafts solid roller camshaft was utilized to maximize this engine's output.

Knowing that the cylinder heads are vital to making engine power, the RHS heads Mid America utilized were completely ported and flowed, then filled with Manley valves and PBM springs, actuated by Harland Sharp rocker arms. To feed this small-block, an Edelbrock Victor single-plane intake was used with a 1,000-cfm 4150 series Holley four-barrel. Making nearly 600 horsepower and well over 500 lb-ft of torque, this stout small-block earned Mid America Racing Engines a respectable third place in the 2010 Engine Challenge.