KTR’s SF-1 Hemi represents the pinnacle of drag racing power. Purpose-built with a 4.9-inch bore space, this all-billet engine was engineered from the ground up for the most extreme competition on the planet. After two years of development, hundreds of dyno pulls, and countless track runs, the SF-1 emerged as our most advanced and dominant platform yet, setting track records four times and qualifying #1 at the 2025 U.S. Nationals in its debut.

Key features include larger bores with superior ring seal, a 70mm camshaft, large keyway lifters, optimized valvetrain geometry tested to 11,000 RPM, and enhanced serviceability with cylinder heads removable while the intake remains in place. An improved oiling system, larger fasteners, and KTR’s industry-first 4.9 block-mounted starter, allowing oil pan removal without touching the starter, set the SF-1 apart.

Compatible with screw-blown, roots-blown, centrifugal, and turbocharged combinations, the SF-1 establishes a new benchmark in reliable, repeatable power delivery.