Chevrolet Gemini small-block engine

Gemini small-block engine
Overview
ManufacturerGeneral Motors (Chevrolet)
Production2022–present
Layout
Configuration90° V8
Displacement5,463 cc (333.4 cu in)
Cylinder bore104.25 mm (4.104 in)
Piston stroke80 mm (3.1 in)
Cylinder block materialSand-cast A319 Aluminum
Cylinder head materialAluminum
ValvetrainDOHC 4 valves
Compression ratio
  • 12.5:1 (LT6)
  • 9.8:1 (LT7)
RPM range
Max. engine speed8,600 RPM (soft), 9,000 RPM (hard)
Combustion
TurbochargerTwin-turbo (LT7)
Fuel system
ManagementGM E68 (32-bit)
Fuel typeGasoline
Oil systemDry sump
Cooling systemWater-cooled

The Chevrolet Gemini small-block engine is a dual-overhead cam (DOHC) V8 engine designed by General Motors. While technically a small-block engine because of its bore spacing of 4.4 inches, General Motors engineers do not consider it to be a part of the traditional Chevrolet small block lineage because of the substantial reworking, specialized development, and unique technical features distinguishing its design.

The Gemini is a clean-sheet design, mechanically unrelated to both the LS-based engines and the Cadillac Blackwing V8. Its most notable traits include a flat-plane crankshaft and dual-overhead camshafts, which represents a departure from the traditional pushrod valves and crossplane crankshafts found in all previous generations of Chevrolet small-block engines. As of July 2024, the Gemini engine has two variants, dubbed LT6 and LT7.