General Motors LS-based small-block engine

This article is about the third, fourth, fifth, and sixth generation of Chevrolet/General Motors small-block engine. For the first- and second-generation Chevrolet small-block engine, see Chevrolet small-block engine (first- and second-generation). For the engine found in the C8 Corvette Z06, see Chevrolet Gemini small-block engine.

General Motors LS small-block engine
An LS1 engine in a 1998 Chevrolet Camaro
Overview
ManufacturerGeneral Motors
DesignerTom Stephens[1]
Ed Koerner[1]
Production1997–present
Layout
Configuration90° V8, 90° V6
Displacement293–511 cu in (4.8–8.4 L)
Cylinder bore3.78–4.185 in (96.0–106.3 mm)
Piston stroke3.3–4.125 in (83.8–104.8 mm)
Cylinder block materialAluminum
Cast iron
Cylinder head materialAluminum
Cast iron
Valvetrain
  • 16-valve, OHV (2 valves per cyl.)
Compression ratio9.08:1–13.1:1
Combustion
Fuel systemFuel injection, carburetors[N 1]
Fuel typeGasoline, E85
Oil systemWet sump, Dry sump
Cooling systemWater-cooled
Output
Power output255–755 hp (190–563 kW)
Torque output285–715 lb⋅ft (386–969 N⋅m)
Dimensions
Dry weight402–464 lb (182–210 kg)[3][4]
Chronology
PredecessorChevrolet small-block engine (first and second generation)
SuccessorChevrolet Gemini small-block engine

The General Motors LS-based small-block engines are a family of V8 and offshoot V6 engines designed and manufactured by the American automotive company General Motors. First introduced in 1997, the family is a continuation of the earlier first- and second-generation Chevrolet small-block engine, of which over 100 million have been produced altogether[5] and is also considered one of the most popular V8 engines ever.[6][7][8][9] Spanning three generations, a new, sixth generation is expected to enter production soon.[10][11] Various small-block V8s were and still are available as crate engines.[12][13]

The "LS" nomenclature originally came from the Regular Production Option (RPO) code LS1, assigned to the first engine in the Gen III engine series. The LS nickname has since been used to refer generally to all Gen III and IV engines,[14] but that practice can be misleading, since not all engine RPO codes in those generations begin with LS.[15] Likewise, although Gen V engines are generally referred to as "LT" small-blocks after the RPO LT1 first version, GM also used other two-letter RPO codes in the Gen V series.[16][17]

The LS1 was first fitted in the Chevrolet Corvette (C5),[18] and LS or LT engines have powered every generation of the Corvette since (with the exception of the Z06 variant of the eighth generation Corvette, which is powered by the unrelated Chevrolet Gemini small-block engine).[19] Various other General Motors automobiles have been powered by LS- and LT-based engines, including sports cars such as the Chevrolet Camaro/Pontiac Firebird and Holden Commodore, trucks such as the Chevrolet Silverado, and SUVs such as the Cadillac Escalade.[1]

A clean-sheet design, the only shared components between the Gen III engines and the first two generations of the Chevrolet small-block engine are the connecting rod bearings and valve lifters.[1] However, the Gen III and Gen IV engines were designed with modularity in mind, and several engines of the two generations share a large number of interchangeable parts.[20] Gen V engines do not share as much with the previous two, although the engine block is carried over, along with the connecting rods.[21] The serviceability and parts availability for various Gen III and Gen IV engines have made them a popular choice for engine swaps in the car enthusiast and hot rodding community, and sometimes is known colloquially as an LS swap.[22][23][24] These engines also enjoy a high degree of aftermarket support due to their popularity and affordability.[25]

  1. ^ a b c d Strohl, Daniel (January 19, 2021). "The definitive Hemmings guide to the GM/Chevy LS-series V-8s". Hemmings Motor News. Retrieved March 19, 2023.
  2. ^ Cite error: The named reference oac1 was invoked but never defined (see the help page).
  3. ^ "How much does it weigh?". pro-touring.com. April 20, 2009.
  4. ^ "Intro to the LS1 and LS6". Summit Racing Equipment. June 6, 2017.
  5. ^ Lingeman, Jake (November 28, 2011). "GM builds 100-millionth small-block engine". Autoweek. Retrieved March 18, 2023.
  6. ^ Prosser, Dan (July 26, 2019). "The world's greatest car engines". Autocar. Retrieved March 18, 2023.
  7. ^ McGuire, Bill; Freiburger, David (April 19, 2012). "Reader Voted - 20 Best V8s of All Time - Hot Rod Magazine". MotorTrend. Retrieved March 18, 2023.
  8. ^ Katsianis, Jordan (April 22, 2021). "Best V8 cars past and present – our favourite eights and the cars they're found in". evo. Retrieved March 18, 2023.
  9. ^ "10 Longest Produced American V8 Engines – Autowise". Retrieved March 18, 2023.
  10. ^ Gonderman, Monica (January 23, 2023). "The V-8 Is Not Dead: GM Confirms New Sixth-Gen Small-Block". MotorTrend. Retrieved March 20, 2023.
  11. ^ Perkins, Chris (January 23, 2023). "GM Spending $854 Million to Build New Small-Block V-8". Road & Track. Retrieved March 20, 2023.
  12. ^ "Ranked: the longest-living car engines". Autocar. Retrieved March 18, 2023.
  13. ^ "LS7 and LS427/570 Engines Discontinued by Chevrolet". MotorTrend. January 31, 2022. Retrieved March 19, 2023.
  14. ^ Garbe, Eric (January 21, 2022). "A Guide to LS Cylinder Heads". Engine Builder Magazine. Retrieved March 20, 2023.
  15. ^ Garbe, Eric (January 21, 2022). "A Guide to LS Cylinder Heads". Engine Builder Magazine. Retrieved March 18, 2023.
  16. ^ "Everything You Want To Know About The GM Gen V / LT Engine". Holley Performance Products. Retrieved March 18, 2023.
  17. ^ Panait, Mircea (August 28, 2021). "General Motors LT Small-Block V8 Engine Guide". autoevolution. Retrieved March 19, 2023.
  18. ^ Rupp, Steven; Udy, Jason (February 27, 2023). "The Legendary Small-Block Chevy V-8: A Look Back at Its Highlights and Evolution". MotorTrend. Retrieved March 20, 2023.
  19. ^ Sherman, Don (February 21, 2022). "LT6 Breakdown: The Z06's 670-hp V-8 is a landmark achievement". Hagerty Media. Retrieved March 19, 2023.
  20. ^ "LS Gen III vs Gen IV Swap Guide". www.ictbillet.com. Retrieved March 19, 2023.
  21. ^ Smith, Jeff (December 14, 2020). "Everything You Want To Know About The GM Gen V / LT Engine". Holley Performance Products. Retrieved March 19, 2023.
  22. ^ "9 Popular Engine Swaps - Choose Wisely". MotorTrend. March 26, 2014. Retrieved March 19, 2023.
  23. ^ Garbe, Eric (August 12, 2021). "Popular Engine Swaps". Engine Builder Magazine. Retrieved March 19, 2023.
  24. ^ "Everything You Need to Know About LS, LSX, and Vortec Engines: Specs, History, Swaps, and More". MotorTrend. Retrieved March 21, 2023.
  25. ^ "Guide to LS engine swaps". WhichCar. May 25, 2018. Retrieved March 19, 2023.


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