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.

2007 participants
Diamondback EnginesIndy Cylinder Head
7723 FM 7238621 Southeastern Ave.
Richmond, TX 77469Indianapolis, IN 46239
281/238-6900317/862-3724
diamondbackengines.comindyheads.com
Mid America Racing EnginesMRL Performance
1945 W. 18th St.4651 Culley Ln.
Washington, IA 52353Jackson, MI 49201
319/653-6282517/569-2672
midamericadb@lisco.commrlperformance@peoplepc.com
Muscle MotorsR.M. Competition
2085 Glenn St.28648 Maple
Lansing, MI 48906Roseville, MI 48066
517/482-4900586/909-1591
musclemotorsracing.comrmcomprandy@yahoo.com
Schurbon Engine and MachineSpeed-O-Motive
203 S. Clark St.131 W. Lang Ave.
Maquoketa, IA 52060West Covina, CA 91790
563/652-3100626/869-0270
schurbo@msn.comspeedomotive.com

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.