Tomorrow's Technician August 2012 : Page 8
Class Work Completed That 454 GMC block was the main component used in the build-up, with most of the remainder being aftermar-ket parts and pieces. block to 489 cubic inches with a capability of 500 horsepower. It took awhile, but the mission was accomplished — actually 528 horses and 500 ft.-lbs. of torque on the dyno. After tuning and refinement, he fig-ures that 600 hp is possible. King explained that he line-honed, de-burred, square-decked and did a 0.030 overbore, which added about 35 cubic inches. Finally, he balanced it at 850 rpm on a Sunnen crankshaft balancer. The heads selected were 454 LS-6 ver-sions, which also required work. “I did some porting to take off some rough edges from the casting, which helped the air flow,” King said. “I also port-matched the gaskets between the intake manifold and head.” The compression ratio achieved was 10.5-1. Also, the valves needed attention and King cleaned up the facings. The gas-fuel mixture is provided by a monster 1100 cfm Demon four-barrel. The cam was initially planned to be a moderate flat-tappett, but he later decided on a more-aggressive mechanical roller type. The crank is aftermarket Eagle. Coming from a drag racing family, it’s not surprising that the planned purpose of this engine. “I have a 1991 rail dragster that I run on a 1/8-mile strip,” King said. “I’m hoping I can get into the mid-fives with this engine powering it.” Engine Build-Up #2 At 42 years of age, Dave Lemke (right)of Dayton, OH, describes himself as an “old school” mechanic. Lemke, who owns an auto repair and towing business in Michigan, said his new quest is to concentrate on his hobby and establish himself as a high-performance builder. “With this build-up, I wanted to learn about upgrading the Chevy LS engines.” To that end, he started with a used 140,000-mile 5.3L LS-1. The goal was to increase the horsepower to about 500 at the wheels. The engine’s final resting point will be in a 1981 Buick Regal. Class Work Completed The block received the initial attention when it was shot-peened and measured. Next, it was punched out 0.125”, plus the addition of an aftermarket stroker cam provided an additional 61 cubic inches of displacement. That produced a 396 cid engine . Lemke also wanted better engine oiling and cut a channel on both the front and back of the block to open up a galley. The next procedure was to balance the rotating mass of the engine that included the pistons, rods, pins and clips. Aftermarket parts were used internally with ADP Performance rods and moly pistons. Also, a GM LS7 cam was installed. The stock intake was retained although it was ported and polished and was custom fabricated into a tunnel-ram configuration. The heads received huge attention as Lemke figures he spent about 200 hours of machining on each of them. “I ground off everything that would hurt the flow. I then tested the heads on a Super Flow 1020 Bench and it recorded 278 cfm,” he said. After the headwork was completed, the engine showed a huge increase in compression ratio from initially at 9.5-to-1 to an impressive 12.2-1. The injection system was acquired from an 8.1L Chevy Vortec engine, which produced an injection pressure of 42 lbs. compared to the 5.3’s 29 lbs. of pressure. While both King and Lemke agree that their engine-building lesson at the commu-nity college is a once-in-a-lifetime experience, they are both hopeful that the lessons learned will provide them many engine-building opportunities and steady work in the future. Do you have an outstanding student or a group of students that needs to be recognized for an automotive-related academic achievement? E-mail us at esunkin@babcox.com. 8 TOMORROWSTECHNICIAN.COM 08.12
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