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,[1][2] 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.[3][4][5]

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.[6]

  1. ^ Steven Rupp (October 26, 2021). "Flat-Plane Crank DOHC LT6 to Power the 2023 Corvette Z06! Details and Specs". motortrend.com. Retrieved October 27, 2021.
  2. ^ "2023 CHEVROLET CORVETTE Z06 ELEVATES THE AMERICAN SUPERCAR". media.chevrolet.com. October 26, 2021. Retrieved October 28, 2021.
  3. ^ Joe Kucinski (February 18, 2022). "LT6 Engine Deep Dive: Everything You Need to Know about the Corvette Z06 Flat-Plane-Crank V8". corvetteforum.com. Retrieved March 5, 2022.
  4. ^ Wren, Wesley (February 18, 2022). "5 Fast Facts About Chevrolet's LT6: The Corvette Z06's Heart". AutoWeek.
  5. ^ Kelly, Iain (October 28, 2021). "The LT6 V8: Inside GM's most powerful small-block". Street Machine. WhichCar.
  6. ^ Tingwall, Eric (July 25, 2024). "Monster! The Story of the Corvette ZR1's LT7 V-8 Engine and How It Makes 1,000+HP". MotorTrend.