There's no question that working for a car magazine offers the Mopar Muscle staff all kinds of cool opportunities to attend car shows and races, but one of our favorite annual events is the AMSOIL/Mopar Muscle Engine Challenge. Each year our contest features a different Mopar V-8 engine, and gives engine builders from both large and small shops the opportunity to highlight their engine building technique in a dyno shootout. Each December at the PRI show we announce the featured engine and rules for the contest, then the engine builders have just over eight months to deliver their engines to the Mopar Nationals where our readers can check them out and ask the builders questions. After the Nats, the engines go to Comp Cams' dyno facility in Memphis, Tennessee, where their power is measured on Comp's Superflow engine dynamometer.

Each year of the Engine Challenge we vary the rules of our contest slightly to keep things interesting, and every year our competition features a different variation of a Mopar V-8. In 2009, for the first time since the inception of our contest, we featured the low-deck Chrysler big-block with Edelbrock Performer RPM cylinder heads. We didn't limit displacement this year, and had engines from 451 to 512 cubic inches. By limiting the cylinder head to the street-style Performer RPM, we effectively limited the air that would flow through these engines, or so we thought. We also restricted the competitors to Rockett Brand 93 octane fuel, since 93 octane is about as much as you can find at the pump these days. In effect, by restricting the octane of the fuel, we restricted the compression of these engines, though some of the competitors did push the limits with ratios as high as 12:1. Induction was restricted to 1,350 cfm, leading most competitors to use single four-barrels, but we did have two engines with tunnel-rams and dual quads this year. Additionally, we will factor the cost of all the major parts in each engine, and then divide the cost into the combined peak horsepower and torque for the power per dollar rating that will decide the winner.

With the engines at Comp, we randomly drew the order in which they would be dyno'd, running one engine in the morning and another in the afternoon. During their dyno session, each builder or team had a 45-minute qualifying period in which to make a minimum of three pulls from 3,000 to 7,000 rpm. Then after a 10-minute cool-down period, the team had another 45 minutes to make a minimum of three scored pulls over the same rpm range. The combined peak horsepower and torque from each competitor's best scored pull is the number we will divide into the cost of the engine for a final power per dollar rating.

We haven't yet had time to factor the prices of all the parts that went into these engines so you'll have to wait until next month to find out who won the AMSOIL/Mopar Muscle Engine Challenge, but we thought you'd like to know how the dyno sessions went and what kind of power these big-blocks made. The engine builders used a variety of techniques to try to gain an advantage in this year's contest, and this month we'll show you how they tuned their engines for maximum performance on Comp's dyno. Remember that the run order for our contest was random and doesn't reflect who will actually win the competition, so you'll have to read next month's issue to find that out!

2008 Participants
Indy Cylinder HeadChenoweth Speed and Machine
Indianapolis, IN 46239Morton, IL, 61550
317/862-3724309/266-8084
indyheads.comchenowethspeedandmachine.com
Schurbon Engine and MachineCederstrand Racing Engines
Maquoketa, IA, 52060Brea, CA, 92821
563/652-3100714/653-4523
Cederstrandracingengines.com
JMS Racing EnginesPromax
El Monte, CA, 91732Indianapolis, IN 46222
626/579-4567317/241-3432
jmsracing.comsales@promaxcarbs.com
JD Engine and Machine
Columbia, MO, 65203
573/445-4550