On the inlet side, several different combinations of throttle bodies and intake manifolds
The engine was outfitted with Bosch's outstanding HO7DC spark plugs, ignition timing was programmed in at 26 degrees of total advance from 2,500 rpm up to 7,000, and we were ready to go. Once at the competition, the only real surprise came in the form of coolant temperature. The EFI computer is programmed to bring the engine up to operating temperature (typically 180 degrees, minimum) and make big power there. Until it reaches that point, the computer will run the fuel mix a bit rich (functioning loosely like a choke on a carburetor). Once on the Challenge dyno, the engine was pulled at only 143-150 degrees of coolant temperature and was understandably rich throughout the pull. Our between-rounds tune-up addressed this as much as we could, but it was still rich when our time ran out, and this cost us on the final tally. The TPIS crew learned from this, and will be better prepared next time.
The maximum effort called for by the Engine Masters Challenge forced our crew of experienced performance engine specialists to go back to basics and put what we knew to the test. We learned a lot from start to finish, as the in-house dyno served as our guide while the other competitors gave us inspiration and direction to push the limits even further. Such an engine could serve as a phenomenal street or track engine, with ample power on tap throughout the sub 7,000-rpm range on pump gasoline.
Based on what was learned, TPIS will be offering several LS-based combinations capable of producing broad-based power on low-octane pump gas. These, too, will evolve, like the Challenge entry engine itself, but durability and reliability will remain priority one. With the LS design as a foundation, the future of pump-gas powerplants from TPIS is bright. When the dust settled, the diminutive 383-cube LS bullet belted out 629 peak horsepower at 7,000 rpm-that's well into big-block territory. It's also a warning shot across the bow that TPIS is a player in the wonderful world of LS power.
Here are the two intakes TPIS tested-the Edelbrock Super Victor EFI on the left, and TPIS'
The AFR heads were the key to the engine's capabilities, and here's why TPIS chose to run
The intake port is a cathedral shape, and is ported for optimum flow throughout. The work
The exhaust port is similarly finished with a clear, line-of-sight design and flow number
The valvetrain components are all first-rate. TPIS went with Isky's solid-roller lifters (