2007 AMSOIL Mopar Muscle Engine Challenge - The Final Two Engines

This year's engine challenge has certainly showed us that the small-block Mopar makes great power for the money. We also saw engine builders use a variety of techniques to try to gain an advantage in our competition. Our seventh place engine-built by MRL Performance-was the smallest in the contest at just over 318 ci. While this put engine builder Mike Liston at a disadvantage, we were happy to see at least one builder bring the most common of all LA engines to our contest. Our eighth place finisher-Diamondback Engines-also brought a strong performer to the engine challenge, but unfortunate mechanical problems kept them from making the dyno pulls required by the contest rules. Had Diamondback not had these issues, they certainly would have placed better.

Although the two engines featured this month weren't contest leaders, they were each respectable in their own right. The MRL entry clearly showed that 318s aren't just for daily drivers, they can be real performers. And since more 318s were manufactured than any other Mopar V-8, it's easy to find a rebuildable core. Heck, we've been offered 318 engines free just because someone wanted to clean out their garage. Conversely, the Diamondback entry with its Brodix cylinder heads and a big roller cam was a good example of a stroker small-block. we were a little disappointed when a mechanical issue kept us from seeing its real potential. Even so, the Diamondback entry showed good power during its first qualifying pull and also showed us that parts can fail at any time.

Follow along as we go inside each of these engines to see what tricks each builder used to gain an advantage in this year's challenge.

Chances are engine builder Mike Liston of MRL Performance knew he'd be leaving something on the table by bringing a small displacement engine to this year's contest. To him, it was more about showing the potential of the 318 than it was about making the biggest power numbers. And while his 380 hp was slightly shy of the number Mike hoped for, it's still respectable power from a pump-gas 318.

As a foundation for his build, Mike started off with a '66 318 core engine from which he used the block and forged crankshaft. Instead of utilizing the factory main caps, he installed heavier 340 main caps and line bored the main journals for alignment. Inside his block, Scat connecting rods were utilized along with Keith Black forged pistons for a tough rotating assembly. A Comp flat-tappet camshaft was matched with Howard's Cams solid lifters to actuate the valvetrain, and a Summit timing set was utilized because of its reasonable cost. To ensure proper lubrication, Mike chose a Milodon oil pan with matching windage tray in conjunction with a Melling high-volume oil pump. Additionally, he added oilers in the crankcase to oil the bottom of the pistons to dissipate heat and help prevent detonation. While this modification could have some benefits in high-compression/low-octane applications, it also adds oil and weight to the rotating assembly.

To top off his 318 short-block, Mike used Mopar Magnum cylinder heads. While these heads do require the use of tappets that oil through the pushrods and pedestal-mounted rocker arms, they likely have the best power potential of any factory cylinder head. To keep the valvetrain light, Mike used Comp "beehive" style valvesprings and retainers, and Summit roller rocker arms. While the heads weren't extensively ported, he did clean up the ports and bowls in-house. A Holley vacuum secondary four-barrel and Mopar Performance M-1 single-plane intake topped this 318. a factory style electronic distributor handled the ignition.

Rather than taking the conventional approach to our engine challenge, the crew from Diamondback Engines decided our contest would be a great opportunity to try some new tricks. We love seeing engine shops try new ways to make power, and we appreciate the effort it takes to create new technology that will lead to more powerful engines for our cars. Unfortunately, while the Diamondback Engines entry showed the potential for big power during the first qualifying pull, an issue with rocker arm oiling damaged several rocker arms and kept Diamondback from making the qualifying pulls required by the contest rules. While the problem kept Diamondback from qualifying for the judged pulls of our engine challenge, we certainly appreciate their efforts, and we'll outline the combination they used to finish eighth in this year's challenge.

Like most competitors this year, engine builder Damon Kuhn of Diamondback engines started with a factory 360 block. Inside the Chrysler block, an Eagle forged crank and Eagle H-beam connecting rods were used in conjunction with SRP forged pistons. A Bullet solid roller camshaft was used with Lunati lifters, and oiling was handled by a Milodon pan and windage tray, and Melling oil pump.

To top their short-block, Diamondback chose Brodix B1-BA aluminum cylinder heads. With large valves, huge ports, and a well-designed combustion chamber, these heads have the potential to make power. Atop their engine, an Edelbrock Super Victor single-plane intake was matched with a Diamondback-built four-barrel carburetor.

Though the rocker arm issues kept them from qualifying this year, the crew from Diamondback promised to redeem themselves in a future engine challenge. From the limited data we got during this engine's aborted pull, we know these guys can make power. We look forward to seeing what they can do if they decide to enter a future Mopar Muscle Engine Challenge.