The foundation for the School...
The foundation for the School of Automotive Machinists Cleveland is a World Products Man O’ War block. SAM instructor and team leader Chris Bennett tells us this unit is extraordinarily stout and capable of handling extreme power outputs, even in power-adder applications. Note the massive main structure of the crankcase.
Racing is typically an incremental game, a pursuit of chipping away at the numbers in search of constant improvement. Be it the numbers on the dragstrip, around a circuit, or the very power numbers produced by an engine, keeping pace of this constant raising of the bar is what creates winners. In our annual engine-building competition, the AMSOIL Engine Masters Challenge, the competition likewise is fierce, and innovation is constant, continually demanding advancements in power output to stay in the game. The 435ci Ford Cleveland featured here was built by the School of Automotive Machinists (SAM), and appeared in its first incarnation for the 2006 event. Though it finished well up the pack in the subsequent years, the basic engine combination has been built again and again in a constant game of refinement and development, looking for an outright victory. The AMSOIL Engine Masters Challenge finally rewarded the SAM team in 2011 with an all-out victory in the Street category.
As one of the premier performance engine tech schools in the country, the exercise of building an engine and competing in the Challenge presents a unique opportunity for the School of Automotive Machinists. Of course, the event is a proving ground for the collective talent of the organization, but more than that, competing allows students to gain direct hands-on experience in a highly competitive venue. As team leader and instructor Chris Bennett tells us: “It was 100 percent a class project; everything in it was overseen by myself and other instructors, but all of the critical parts of the engine were done by the students, from the machining to the assembly.”
Even with the reduced rod...
Even with the reduced rod journal diameter, the long stroke makes for tight crankcase clearance at the bottoms of the bores. The bores of the World block feature extended cylinders, helping with piston stability when long strokes are employed. Clearance grinding was required.
Bottom End Basics
The build started with a World Products Man O’ War iron block, configured with a long-stroke combination, featuring a bore of 4.065 inches and a 4.185-inch stroke. Bennett explains: “We wanted to get the piston speed up at lower rpm, so we went with the longer stroke. The goal was to get the air speed up in the manifold and decrease the reversion.” The components inside were selected with long-term durability and quality in mind. The custom Winberg crank features profiled counterweights and extra-small Honda-sized rod journals. Bulletproof Manley 6.000-inch rods with the corresponding 1.888-inch journal dimension complete the assembly. Commenting on the small journals, Chris says: “It cuts the surface area down, and it decreases friction. It also reduces the weight at the rod and the counterweight, and improves the crankcase clearance with the longer stoke.
Custom Wiseco pistons seal the bores, and these were built with several tricks. When the engine was built, gas ports were not legal in the class, however, the ring setup included an extra .030-inch spacer, which contain grooves that effectively mimic the use of lateral gas ports cut into the pistons. The ring package features very narrow-section .325/.325/2mm rings from Total Seal. Chris explained the reasoning behind the narrow rings: “The rings were another frictional reduction. The narrow rings conform to the cylinder better than a wider ring, however, the tune-up becomes more critical. When you have that thin of a ring, it can pinch the ring land a lot easier; the ring land becomes more delicate at that point.”
A custom Winberg crankshaft...
A custom Winberg crankshaft features a stroke of 4.185 inches, and reduced-diameter 1.88-inch Honda-sized journals. The reduced bearing diameter lowers the bearing speed and friction, while the short streamlined counterweights cut down on power-robbing windage.
SAM filled the bores with...
SAM filled the bores with custom Wiseco pistons hung from a set of Manley 6.00-inch connecting rods. The rings were selected with low friction in mind and feature a narrow .0325/.0325/2mm Total Seal ring pack. Clevite bearings and ARP bolts complete the assemblies.
The Wiseco forgings feature...
The Wiseco forgings feature a heavily reinforced skirt area below, and an inboard piston pin design. This greatly reduces pin weight, while creating a very rigid, stable piston.