Chevrolet Gemini small-block engine

The Gemini is a dual overhead cam V8 that General Motors designed for Chevrolet and that, despite its 4.4 inch bore spacing, GM engineers do not count as part of the traditional small-block line. It is a clean-sheet design, mechanically unrelated to the LS-based engines and to the Cadillac Blackwing V8, and it is the first Chevrolet small-block to use a flat-plane crankshaft and overhead camshafts in place of pushrod valves and a crossplane crankshaft. It comes in two variants. The LT6, a 5.5 litre naturally aspirated engine unveiled on October 26, 2021 for the eighth-generation Corvette Z06, makes 670 horsepower at 8,400 rpm and is the most powerful naturally aspirated production V8 of all time. The LT7 is its twin-turbocharged form, unveiled on July 25, 2024 for the Corvette ZR1 and rated at 1,064 horsepower.