Runge's flat-eight Hetzer engine brings vintage Porsche feel alive

Runge Cars, a US custom car builder, has developed the Hetzer, a hand-built 5.3-liter air-cooled flat-eight engine designed to revive the classic Porsche air-cooled experience with modern engineering. Featuring dual overhead camshafts, 32 valves (four per cylinder), a 12:1 compression ratio, and a redline of 9,000 rpm, the Hetzer delivers race-inspired performance and a broad powerband. Engineered to fit most air-cooled Porsche 911 models, this engine combines vintage character with advanced CNC machining and motorsport-grade materials, emphasizing balance, performance, and visual appeal. The Hetzer will debut in Runge’s upcoming R3 supercar, a lightweight (1,720 pounds) and analog-focused sports car equipped exclusively with a six-speed manual transmission and rear-wheel drive. The R3’s design features a low-slung front end, circular headlights, and a compact cockpit, with a sweeping rear wing enhancing its performance-oriented aesthetic