2007 AMSOIL Mopar Muscle Engine Challenge - The Final Two Engines

MRL Performance brought the smallest displacement small-block to this year's engine challenge, but still managed to make well over 1 hp per cubic inch for a seventh place finish.

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 valvetrain issues kept Diamondback Engines from competing in the judged portion of our engine challenge, their stroker small-block showed the potential for big power.

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.

We were all eager to see how the Diamondback Engines entry would run, but, unfortunately, it was not to be. During their first qualifying dyno pull, they damaged their rocker arms and weren't able to make repairs in the allotted time, leaving us to speculate about how much power this engine would have made.

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.