The '07 Amsoil/Mopar Muscle Engine Challenge - Tech

The Mopar Muscle Engine Challenge is designed to give our readers insight into what it takes to build a powerful engine economically, without sacrificing reliability. By factoring the combined horsepower and torque the engine makes into the retail cost of the parts in the engine, each engine gets a cost-per-horsepower rating. This forces the builders to choose their parts carefully, walking the line between power enhancement and the almighty dollar to come up with a powerful, yet economical combination. This year, our contest featured the Mopar small-block, limited to 410 ci, and the crew from Indy Cylinder Head had just the right recipe to win this year's Engine Challenge.

As in years past, the top spots in this year's Engine Challenge were separated by a narrow margin. In fact, the top three engines were so close we rechecked our math twice before awarding the win to Indy Cylinder Head. In reality, each of the engine builders in this year's contest brought a competitive engine to the challenge, and we were excited to see such diversity among the engines. These builders really did their homework, using displacements from just over 318 ci to the contest limit of 410 ci, and cylinder heads ranging from nearly stock Magnum heads to fully prepped aluminum units from Brodix and Indy Cylinder Head.

When the numbers were tallied, it was stroker 360s with Magnum cylinder heads that claimed the top three positions of this year's contest. For the money, it's just hard to beat the Magnum cylinder head. And while the Indy and Brodix heads certainly showed the potential for big power numbers, they didn't make enough extra power to gain an advantage over the Magnum cylinder heads once cost was factored. Even the guys from Indy Cylinder Head-this year's winner-resisted the temptation to build an all-out powerhouse using their heads, stating that pump gas and the way our contest rules factor costs, simply favored the Magnum head.

Since our contest is geared toward what our readers are most likely to need-powerful engines that run on pump fuel-Rockett Brand again provided the 93-octane refined petroleum for our competition. We've been using Rockett Brand fuel for a number of years now, both in our engine challenge and in our street and race cars, and the fuel has simply performed flawlessly. If you're like us, and have never really understood the science of octane ratings, specific gravity, and the other chemistry involved with gasoline, we recommend speaking with the guys at Rockett Brand or visiting their web site, rockettbrand.com. If nothing else, you'll learn something about the science behind the fuel you use to power your Mopar.

During the dyno runs at the Comp Cams Memphis, Tennessee, dyno facility, each of the contest engines had to go through a qualifying session involving a minimum of three pulls, and a judged session, again involving a minimum of three pulls during a 45 minute period. This is not only to gather dyno data to factor our results, but also to test the durability of the engines. This year we only had one engine that failed to qualify, and it wasn't a catastrophic failure, just an oiling issue in the rocker-arm area of the Diamondback entry that prevented it from making the required pulls. Otherwise, each engine performed well, if not flawlessly, while performing the dyno pulls with the remaining seven engines making impressive power.

Starting with Indy Cylinder Head, we'll run down the order in which our competitors placed. As we stated, it was a close contest with the top positions being determined by a virtual photo finish. The truth is, we'd be proud to have any of these engines in one of our cars as they are all powerful performers. If you're considering a small-block build for your next project, we encourage you to consider one of the professionals featured in our engine challenge. The results of our contest are a good indication that you won't be disappointed. Also, be sure to stay tuned to future issues as we go inside each of these engines and see what parts and tricks were utilized to make them competitive.

Indy Cylinder Head
Indianapolis, Indiana
The name Indy Cylinder Head evokes visions of high-flowing, high-horsepower, aluminum cylinder heads. So when Indy entered a Magnum-headed stroker small-block in our contest, we had to ask what was up. Engine builder Ken Lazzeri of Indy stated that while he'd love to impress everyone with one of their all-out, 700hp small-blocks, the way our contest factored the costs, a cast-iron headed engine would just be more competitive. So he made the tough decision to go for the win instead of going for impressive power. Actually, we think he accomplished both. The Indy entry was not only one of the most economically built engines in the contest, but its 523 hp was nearly as much as some of the more expensive aluminum-headed engines made.

Schurbon Engine And Machine
Maquoketa, Iowa
Schurbon Engine and Machine is a newcomer to our contest, but they made a lasting impression. The Schurbon engine not only looked good wearing its Plum Crazy paint job, but also performed flawlessly during the dyno session and impressed everyone in attendance with its power and torque. Engine builder Scott Schurbon is no newcomer to Mopar small-blocks, having built and raced them in "roundy-pounders" for many years. Scott loves it when a customer asks for a Mopar engine because he says they make great power for the money, so it's easy to deliver more than the customer expects. The Schurbon entry in our contest certainly delivered more than expected when it screamed to nearly 500 hp and a stump-pulling 460 lb-ft of torque. Scott says he likely left a little on the table as well by utilizing a somewhat small camshaft since this engine was built for a street application. Even so, this small-block finished a strong second and was very close to winning this year's competition.

R.M. Competition
Roseville, Michigan
Randy Malik of R.M. Competition had the right combination to land a third place finish in this year's Engine Challenge, narrowly missing an even better showing. All the top three engines were closely matched, and the top three places were determined by a very narrow margin this year. The R.M. Competition entry looked impressive with its tunnel-ram and dual quads, and ran equally as impressively, making some 510 hp and 442 lb-ft of torque. Using Magnum cylinder heads with the LA-style intake bolt pattern, Randy was able to utilize a tunnel-ram intake without significantly adding to the cost of his engine. We congratulate R.M. Competition on their third place finish.

Mid America Racing Engines
Washington, Iowa
Having competed in all of our Engine Challenges and winning last year's Engine Challenge, engine builder David Bruns of Mid America Racing Engines is no stranger to dyno competitions. He knows it takes a cost-effective and potent combination to place well, and brought a solid small-block to this year's contest. Sporting Indy cylinder heads and a solid roller camshaft, the Mid America entry sounded strong from its initial pull. Tuning with jet and timing changes, and using different carb spacers, David Bruns' engine produced contest-leading power of 567.1 hp and 489.2 lb-ft of torque, earning him a fourth place.

Speed-O-Motive
West Covina, California
Known for building reliable, powerful engines, and placing well in previous competitions, it was no surprise when the Speed-O-Motive entry made more than 518 hp on its first dyno pull. Engine builder Tucker Caven further tuned his entry to the second highest power score of the competition at 529.2 hp and 467.2 lb-ft of torque. Brodix B-1 AMC cylinder heads and a solid roller camshaft combined with a stout 408ci short-block was Speed-O-Motive's key to making big power. Their powerful performance was good enough for fifth place in our competition.

Muscle Motors
Lansing, Michigan
Engine builder Mike Ware of Muscle Motors is widely known for building some of the most powerful engines in drag racing, so we were a little surprised when we saw his 400ci, Six-Pack-equipped small-block. Mike said the explanation was easy-he wanted to be different, had limited time, and was already building this engine for a customer who agreed to enter it in our contest. After the Engine Challenge, this engine will be dropped into a Challenger T/A clone, which explains the triple two-barrel induction. Since the Six-Pack intake is a dual-plane unit and limits top-end power, Mike built this engine for torque, and plenty of it. In fact, the 400-inch engine's 456 lb-ft of torque is a good indication that this engine could have made significantly more power if topped with a single-plane intake. Even limited, this engine placed a very respectable sixth place in a tight competition

MRL Performance
Jackson, Michigan
Instead of setting his sights on huge power numbers in this year's contest, engine builder Mike Liston of MRL Performance decided he'd rather show the potential of the most widely produced, and most widely overlooked, small-block-the 318. Though Mike fell a bit short of his goal of 500-plus horsepower, his Magnum-headed 318 ran well and produced nearly as many horsepower per cubic inch as the top engines in the contest. At over 380 hp, this 318 would be a blast in a street-driven A-body. We congratulate MRL Performance on their seventh place finish, and, more importantly, for showing that 318s can be performance engines.

Diamondback Engines
Richmond, Texas
Diamondback Engines drew the first dyno slot in this year's Engine Challenge, and, unfortunately, their engine had problems during their first qualifying pull. After inspecting the damage, engine builder Damon Kuhn decided the damage was too extensive to attempt a repair and pulled his engine from the competition. Though we don't know how this engine would have placed since it didn't qualify, the guys from Diamondback agreed to make repairs to their damaged rocker arms and re-dyno the engine at their facility. Look for their numbers in an upcoming issue.