Gemini small-block engine
Overview
ManufacturerGeneral Motors (Chevrolet)
Production2022–present
Layout
Configuration90° V8
Displacement
  • 5,463 cc (333.4 cu in)
Cylinder bore
  • 104.25 mm (4.104 in)
Piston stroke
  • 80 mm (3.1 in)
Cylinder block material
Cylinder head materialAluminum
ValvetrainDOHC 4 valves
Compression ratio12.5:1
RPM range
Max. engine speed8,600 RPM (soft), 9,000 RPM (hard)
Combustion
Fuel systemDirect fuel injection
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 LT6 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 February 2024, the Gemini engine has only one variant, dubbed LT6. Hagerty, an American insurance company, reported in 2020 that a higher horsepower variant, the LT7, is expected to arrive in the 2024 model year.[6]

LT6

The LT6 is a 5.5-liter, naturally-aspirated V8 engine. It debuted in the eighth-generation Corvette Z06, and was unveiled on October 26, 2021.[1]

While the LT6 features a redline of 8,600 RPM, it generates a maximum of 670 hp (500 kW; 679 PS) at 8,400 rpm and 460 lb⋅ft (624 N⋅m) of torque at 6,300 RPM. These figures make it the most powerful naturally-aspirated production V8 engine of all time; the engine to previously hold this title, the Mercedes-Benz SLS AMG Black Series M159 6.2-liter V8, made 622 hp (464 kW; 631 PS) at 7,400 RPM. [7][8][1]

The LT6 is also the largest flat-plane V8 used in a production car by displacement, dethroning the Ford Voodoo. This is notable due to the additional vibrations inherent to this architecture compared to a crossplane V8, which tend to scale up with displacement.[9]

A modified version of the LT6 has powered the C8.R since 2019, and many features in the racing engine carry over to the road engine.[2] Other notable LT6 features include a cast aluminum block, dual coil valve springs supporting titanium intake & sodium filled exhaust valves, forged aluminum pistons, forged titanium connecting rods, active split intake manifold with twin 87mm throttle bodies, four-into-two-into-one stainless steel exhaust headers, and a factory six-stage 10-quart dry sump oiling system with individual crank bay scavenging.[1]

Applications:

Year(s) Model Power Torque Dyno Chart
2023–present Chevrolet Corvette Z06 670 hp (500 kW) @ 8400 rpm 460 lb⋅ft (624 N⋅m) @ 6300 rpm link

See also

References

  1. ^ a b c d ,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. ^ a b "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. ^ Padeanu, Adrian (April 23, 2020). "Chevy Corvette C8 Future Reportedly Leaked, Zora Hybrid Has 1,000 HP". motor1. Retrieved July 18, 2023.
  7. ^ Markus, Frank (October 26, 2021). "How the C8 Corvette Z06's LT6 Became the World's Most Powerful Naturally Aspirated Production V-8". MotorTrend. Archived from the original on October 26, 2021.
  8. ^ Colwell, K.C. (October 26, 2021). "2023 Chevy Corvette Z06 Brings 670 HP of Naturally Aspirated Fury". Car and Driver. Archived from the original on October 26, 2021.
  9. ^ Sommers, Alex (September 7, 2021). "Chevy's eighth-gen Corvette Z06 is poised to topple these 3 production-car V-8 records".
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