The '07 Amsoil/Mopar Muscle Engine Challenge - Tech

To optimize power from this potent small-block, the Indy crew used a Comp solid flat-tappet camshaft and Indy rocker arms to actuate the valve gear. Comp "beehive" springs kept the valves under control at rpm, and an MSD distributor fired the cylinders. An Indy single-plane aluminum intake matched with a Demon 850 four-barrel carburetor took care of induction, and Schoenfeld headers expended the burnt gasses. To save costs, factory valve covers were used, along with a factory timing cover and oil pan. Overall, this engine made great power from economical hardware, and we really enjoyed seeing the crew from Indy optimize an engine that didn't wear Indy heads. We congratulate Indy Cylinder Head for winning the '07 Amsoil/Mopar Muscle engine challenge.

Schurbon Engine And Machine
Maquoketa, Iowa
When we spoke with Scott Schurbon of Schurbon Engine and Machine at the beginning of our contest, he stated he would bring a strong engine, but wouldn't sacrifice reliability for power. Scott said his engine would be one just like he would sell his customers, and he wouldn't use cheap parts simply to place better in the contest. During the dyno portion of the challenge, it was apparent this engine was not only a strong performer, but also had the potential to place very well in the contest. Scott and his crew effectively tuned their entry to more power on each pull, even swapping to a smaller, less expensive carburetor without losing power. This engine sounded strong and smooth, and performed flawlessly allowing Scott plenty of time to tune his engine to nearly 500 hp and a stump-pulling 460 lb-ft of torque!

Everyone agreed that the Schurbon entry looked great wearing its Plum Crazy purple paint job, and it performed as good as it looked once on Comp's dyno. Inside their factory 360 block, Scott utilized an Eagle cast-crankshaft, RPM connecting rods, and Probe pistons to net a displacement of 410 ci. A standard volume Melling oil pump was matched with a Moroso oil pan, but we noticed the absence of a windage tray in this engine. When asked why, he stated the windage tray would have to be modified to work properly, and he simply ran out of time before the engine had to be delivered to the Mopar Nationals so he welded baffles into his oil pan instead. Even with no windage tray, this engine performed flawlessly and had no oil-related issues while making its dyno pulls.

To top his short-block, Scott used cast-iron Magnum cylinder heads that were ported in-house for optimal flow. Since this is a street engine, Scott decided not to overdo it when it came to port volume and camshaft. He says he likely left a little on the table as a larger cam would have made more power, but at 460 lb-ft of torque, this engine would perform great in a street car. Inside his cylinder heads, Scott used extreme-duty, stainless steel valves and Comp springs. A Comp solid flat-tappet camshaft actuated the valve gear through Scorpion roller rocker arms. Scott manufactured a stud girdle for the rockers in-house and had no problems spinning his engine to the required 7,000 rpm. A factory Mopar timing cover and Mopar aluminum valve covers were used to keep costs down.