GM L3B engine explained

General Motors L3B engine
Manufacturer:General Motors
Production:2018–present
Configuration:Inline-4
Displacement:2727cc
Bore:92.25abbr=onNaNabbr=on
Stroke:102abbr=onNaNabbr=on
Cylinder Spacing:NaNabbr=onNaNabbr=on
Block:380 T5 Cast Aluminum
Head:356 T5 Cast Aluminum
Valvetrain:DOHC 4 valves/cyl with VVT and VVL
Compression:10.0:1
Turbocharger:Single BorgWarner Dual-Volute w/ electrically actuated wastegate
Fuelsystem:Gasoline direct injection
Fueltype:Gasoline
Oilsystem:Wet sump
Coolingsystem:Water cooled
Redline:6100 RPM
Power:NaNabbr=onNaNabbr=on
Torque:NaNabbr=onNaNabbr=on
Sp:us
Emissions Level:Tier III, Bin 50
Emissions Control:Three-way catalytic converter, wide-band heated oxygen sensor

The GM L3B engine is a turbocharged four-cylinder gasoline engine designed by General Motors. It is an undersquare aluminum DOHC inline-four displacing 2.7 liters (165 cid) and tuned for strong low-end torque.

In addition to GM's active fuel management, start-stop system, and variable valve timing, which are already featured on GM's other full-size pickup truck engines, this engine also features GM's Intake Valve Lift Control which has 3 different intake cam profiles that are electromagnetically actuated to provide improved fuel economy and performance at a wider range of operating conditions.[1]

The BorgWarner developed turbo can produce up to 27psi of boost thanks in part to its unique dual volute turbine housing and an electrically actuated wastegate. Instead of two side-by-side exhaust passages like on a regular twin-scroll turbocharger, in this design the two exhaust passages are concentric and allow for better use of the exhaust pulse energy.[1]

History

The L3B was first used in the Chevrolet Silverado and GMC Sierra, with an output of 3100NaN0 at 5600 RPM and 348lbft at 1500 RPM. With the unveiling of the 2022 model year Silverado, GM announced a significant revision that stiffened and strengthened the engine allowing for a GM-estimated increased maximum torque rating of 430lbft while also improving noise, vibration, and harshness (NVH).[1] Parts are cast at Bedford Casting Operations in Indiana.[2] Assembly is at Spring Hill Manufacturing, Tennessee, USA.[3] The L3B is the successor to the 3.6L V6 LGX, 3.6L V6 LGZ, and 4.3L V6 LV3 engines.[3]

Specifications

The engine is the first GM truck engine to feature an active thermal management system. This system consists of an electrically driven water pump and a 3-way rotary valve which allows the engine to maintain proper operating temperatures and quicker warm-ups. Also, a continuously variable oil pump helps to lower parasitic losses as well as providing proper lubrication and cooling to the engine, especially under high-load conditions.[1] The Active Fuel Management system can shutdown the middle two cylinders under low-power conditions.[2]

Cylinder liners are spun nodular iron.[2]

The low-output work truck variant runs 10 psi of boost, the 390 lb⋅ft variant runs 20 psi, and the 430 lb⋅ft variant runs 27 psi.[2]

Applications

Year(s)ModelPowerTorqueNotes
2019–2021Chevrolet Silverado and GMC Sierra 1500310abbr=on0abbr=on @ 5600 RPM348lbft @ 1500 RPM
2022–present310abbr=on0abbr=on @ 5600 RPM430lbft @ 3000 RPM TurboMax name
2020–presentCadillac CT4310abbr=on0abbr=on @ 5500 RPM350lbft @ 1500 RPM
2020–presentCadillac CT4-V325abbr=on0abbr=on @ 5500 RPM380lbft @ 2000 RPM
2023–presentChevrolet Colorado237abbr=on0abbr=on @ 5600 RPM259lbft @ 3000 RPM detuned with different components, RPO code L2R
2023–present310abbr=on0abbr=on @ 5600 RPM390lbft @ 2000 RPM
2023–presentChevrolet Colorado and GMC Canyon310abbr=on0abbr=on @ 5600 RPM430lbft @ 3000 RPM

2.5L LK0

Year(s)ModelPowerTorqueDyno Chart
2024–presentChevrolet Traverse @  rpm @  rpm
GMC Acadia

Notes and References

  1. Web site: Sherman. Don. All-new four-cylinder for 2019 Chevrolet Silverado. www.sae.org. SAE.org. 28 May 2018. en.
  2. Interview with Kevin Luchansky, GM Assistant Chief Engineer, https://www.youtube.com/watch?v=fU-bhEjflwo, Aug 18, 2023
  3. Web site: GM 2.7 Liter I-4 Turbo L3B Engine. Staff writer. 19 August 2023.