MRL Performance brought the...
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...
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.
|Diamondback Engines||Indy Cylinder Head|
|7723 FM 723||8621 Southeastern Ave.|
|Richmond, TX 77469||Indianapolis, IN 46239|
|Mid America Racing Engines||MRL Performance|
|1945 W. 18th St.||4651 Culley Ln.|
|Washington, IA 52353||Jackson, MI 49201|
|Muscle Motors||R.M. Competition|
|2085 Glenn St.||28648 Maple|
|Lansing, MI 48906||Roseville, MI 48066|
|Schurbon Engine and Machine||Speed-O-Motive|
|203 S. Clark St.||131 W. Lang Ave.|
|Maquoketa, IA 52060||West Covina, CA 91790|
We were all eager to see how...
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.
MRL PerformanceJackson, MichiganThough...
MRL PerformanceJackson, MichiganThough low on displacement, this 318 wasn't low on power. At 380 hp, this would be a fun engine in a street driven A-body.
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.
Though rocker arm issues kept...
Though rocker arm issues kept Mike busy making repairs to his 318, he still managed to make the required pulls, tuning his engine to a seventh place finish.
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.
Inside his factory 318 block,...
Inside his factory 318 block, Mike used a Comp solid flat-tappet camshaft to optimize power.
Keith Black forged pistons...
Keith Black forged pistons were used in this 318 for a compression ratio of approximately 10.9:1.
A stock forged crankshaft...
A stock forged crankshaft was used in conjunction with Scat connecting rods to form a tough bottom end. Note the heavier 340 main caps installed in place of the factory 318 units.
In addition to a Milodon oil...
In addition to a Milodon oil pan, Milodon windage tray, and Melling high-volume oil pump, Mike added these oil squirters to oil the bottom of the pistons. While this may help detonation when compression is pushed to the limit with very lightweight pistons, it also adds the weight of extra oil to the rotating assembly.
Like many of this year's competitors,...
Like many of this year's competitors, MRL Performance used Magnum cylinder heads. These heads offer great potential for the money, making Magnum head swaps very popular for small-blocks.
Comp "beehive" valvesprings...
Comp "beehive" valvesprings are some of our favorites because they offer great valve control while lightening the valvetrain to free up horsepower.
Though not as powerful as...
Though not as powerful as a stroked 360, Mike did show that the 318 shouldn't be overlooked as a performance engine. With the right combination of parts, the 318 can be a great choice for an A-body street/strip car.
While porting some of the...
While porting some of the pinch area from the intake ports is a common way to improve flow, Mike chose to leave his Magnum ports pretty much stock, stating the 318 just doesn't have the displacement to justify the extra flow.
To top his 318, Mike ported...
To top his 318, Mike ported a factory Mopar M-1 intake manifold in-house, then added a Holley 750-cfm vacuum secondary carburetor to handle mixing the fuel and air.
Not scared to take a less...
Not scared to take a less conventional approach, the guys at Diamondback Engines are known for making power. needless to say, we were eager to see what kind of numbers their stroked small-block could produce.
During initial start-up, the...
During initial start-up, the Diamondback entry sounded strong. Had it survived, this engine would have certainly placed better than eighth in this year's contest.
Hearing a noise during their...
Hearing a noise during their first qualifying pull, engine builder Damon Kuhn quickly aborted the run well before the required 7,000 rpm. Unfortunately, the damage was already done and was too extensive to repair in the allotted time, which resulted in a disqualification.
Though we didn't perform a...
Though we didn't perform a complete teardown on the disqualified Diamondback entry, we did notice several tricks they employed, such as "tunneling" the cam with epoxy to direct returning oil away from the cam and rotating assembly.
Though disappointed this year,...
Though disappointed this year, look for the crew from Diamondback Engines to compete in future engine challenges. If this year's entry is any indication, these guys have what it takes to be competitive. We congratulate the crew from Diamondback Engines for trying new technology and thinking outside the box.