Power Parts

Bischoff says, the key to making this engine deliver its outstanding power is in the cylinder heads: Edelbrock’s Glidden SC-1. The cylinder heads are modified while taking into consideration the rpm range and cubic inches, as well as the camshaft profile. Experience is the key here, as Bischoff tells us: “The cross-sectional area has to work as we pass through the lower rpm range; we look at the flow and cross-section and the required cam area to make the engine speed come in where it needs to be. It comes down to experience. We keep records of everything we have done in the past, and it gives us a frame of reference. The particular ports on this engine we had never run on anything else; we developed it just for this engine. We relied on previous experience, and just put it on there and it worked.” The heads come with undersized ports designed for custom porting, and BES Racing has their own CNC machine to do the job. For this particular port, the port size is a resized version of BES Racing’s drag racing port. Bischoff expanded: “I’m impressed with the software on the Rottler CNC machine. We can go in and make changes to the ports on the machine’s programming instead of the way we used to do it, starting over with hand grinding. We were able to alter the size and even slightly modify the position of the ports with the machine.”

One of the features of the engine that attracts attention is the unique intake manifold arrangement. The Edelbrock intake manifold was fitted with a custom-made 4-inch plenum spacer, which was custom blended to the manifold plenum, in addition to an HVH-tapered 2-inch spacer. Bischoff says: “We built that spacer to try and pick up the score, but we tested a manifold that just used a conventional spacer, and it scored exactly the same. It didn’t even change the rpm range. In the end we just left it on there because it looked good.” The carburetor is a 1250 Holley, reworked by Pro Systems, and it was simply adjusted with air bleed and jets at BES Racing. Bischoff says: “We could have spent more time on it, but we didn’t want to wear the engine out on the dyno.”

The block was fitted with 55mm roller cam bearings to accept a large-journal custom COMP roller cam. The large journal allows larger lobes, which makes the cam much more stable and accurate, especially with the heavy valvespring loads used on this engine. COMP ground the cam with 252/262 degrees duration at .050 and a lobe separation angle of 112 degrees. Lift works out to a whopping .940 inch with the very high ratio 2.00/2.08:1 Jesel shaft-mounted rocker arms. Believe it or not, Bischoff says this cam profile is a bit milder than what he would consider optimal: “We didn’t run lobes that were nearly as aggressive as we considered, but we started there, and were happy with the output and just left it.” Jesel also was the supplier of choice for the .904-inch diameter tie-bar roller lifters. With the PSI valvesprings delivering 410 pounds of seat load and 1,000 pounds open load, the valvetrain all has to be bulletproof. Bischoff says the SC-1 engine combination has a very good valvetrain layout: “One thing I really like about the head is that the valvetrain is really good; it is easy on the springs and is very durable.”

Other key details included the custom-built headers put together from a Schoenfeld Sprint Car kit. Bischoff says: “We started with the primary tubes a little longer, and shortened them some, and it helped the score a few points.” A complete ICE ignition system provides the spark, including an ICE Ignition Booster, which increases the voltage. Bischoff says, in his experience, the ICE ignition seems to produce more spark energy than competitive ignition systems.

Taking this concept of a proven combination based on familiar parts to the dyno at the 2011 AMSOIL Engine Masters Challenge, BES Racing was clearly ready to show their capabilities. In qualifying trials, the engine handily made its way to the front of the pack, belting out as much as 913 peak horsepower in the process. Bischoff and crew went into final eliminations as solid front-runners. In the finals, Bischoff advanced the cam by a single degree, which cost 12 hp at peak. Nevertheless, the engine was still over the 900hp mark in peak output, with the incredible torque curve ensuring a lock on First Place. With big power being the name of the game, BES once again found themselves in the winner’s circle.