The 2008 Amsoil/Mopar Muscle Engine Challenge - Schurbon Engine And Machine

Though Scott was a good sport about his mistake, we know that he's actually very serious about his work. Scott is an accomplished and professional engine builder having placed second only to Indy Cylinder Head in last year's competition, and the employees of Schurbon Engine and Machine are equally as dedicated to their profession. This year the 440 they entered in our contest would have certainly been a top contender had it not been damaged during its first pull. While Scott claims there's no excuse for his mistake, to us it serves as a good example of how stress and unfamiliar equipment can cause even a true professional to make an error. As we evaluate the Schurbon Engine and Machine entry in this month's issue, remember that the power numbers don't indicate the true potential of this engine, nor are they indicative of Scott's abilities.

Starting with a seasoned factory 440 block, Schurbon Engine and Machine performed all the necessary machine work in-house, squaring and decking the block and boring it .060 inch oversize. For a strong rotating assembly, Schurbon utilized an RPM forged steel crankshaft and RPM I-beam forged steel connecting rods along with Probe forged pistons. Total Seal Piston Rings were used to seal the cylinders, and Fel-Pro gaskets and seals kept the oil and coolant where it was supposed to be. Clevite bearings were utilized throughout the engine, and a Melling oil pump was combined with a Moroso pan and fabricated windage tray to keep everything lubricated with Amsoil synthetic oil. A Chenoweth main stud girdle was also employed, giving the mains extra support, and ARP studs and fasteners were used throughout the engine. When picking a camshaft, engine builder Scott Schurbon enlisted the help of the Comp Cams engineering department to help recommend a solid-roller camshaft for this application. The cam they chose had nearly .800 inch intake and exhaust lift with 271/279 degrees of duration at .050 inch lift respectively, and was spun by an Engine Pro timing chain and gears.

Topping this stout 440, Schurbon Engine and Machine utilized the same Indy SR aluminum cylinder heads that our rules required each builder to use. Starting with the bare CNC castings, the heads were ported and flowed in-house for optimum performance. Knowing the loss suffered by Schurbon, engine builder David Bruns of Mid-America Racing Engines graciously offered his time to help with the cylinder head porting. Ferrea 2.19-inch intake and 1.88-inch stainless steel exhaust valves were installed after the port work was finished and Comp Cams springs, retainer, and locks were utilized. PRW roller rocker arms were used for their strength, durability, and relative low cost. For induction, an Edelbrock Super Victor single-plane aluminum intake manifold was installed, and a modified Holley Dominator handled mixing the fuel and air. To ignite the mixture, an MSD Pro-Billet distributor and Super Conductor plug wires were used for their proven performance.

Editor's Note: In the May issue, we incorrectly stated that the cylinder head porting performed on the Chenoweth Speed and Machine entry was accomplished by Indy Cylinder Head. The CNC porting was actually performed by Jeff Kobylski of Modern Cylinder Head. Additionally, the camshaft in the Chenoweth's engine was changed just before the engine was delivered to a custom grind recommended by Comp Cams engineer Chris Padgett. The actual specs of the camshaft are .269 degrees on the intake, and .280 degrees of duration on the exhaust at .050 inch lift, with .800 inch lift on the intake and .772 inch lift exhaust.