LT Engines

LT4 6.2L Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

 
LT4 swap engine specs

(Image/Automobileman.com)

This is an engine specification guide for General Motors’ fifth-generation supercharged LT4 engine that launched in 2015.

GM has built two different engines designated as the LT4:

  • 1996–1997 LT4 – Gen II, 5.7L, small block
  • 2015–Present LT4 – Gen V, 6.2L, supercharged small block

The high-performance 6.2L, supercharged Gen 5 LT4 debuted in the 2015 Chevy Corvette Z06.

LT4 6.2L engines are all aluminum and use Active Fuel Management (AFM) and Variable Valve Timing (VVT). The engines also use direct fuel injection technology, which shoots fuel directly into the combustion chamber instead of the intake runner.

The LT4 is not Flex Fuel-capable (E85).

The LT4 makes 195 horsepower and 195 ft.-lbs. of torque more than its naturally aspirated cousin, the LT1. To accomplish this, the LT4 uses:

  • A compact, 1.7L blower
  • A stronger crank, rods, and pistons
  • Rotocast aluminum heads

Some versions of the LT4 came with a dry sump oiling system.

An LT4 6.2L crate engine is now available.

The information listed below is for a stock engine.

(Summit Racing’s Brian Nutter and Paul Spurlock contributed to this article.)

Chevy LT4 Engine Specs

LT4 Performance Specifications

Engine Ratings
Compression Ratio10:1
Horsepower Rating640-650 hp @ 6,400 rpm
Torque Rating630-650 ft.-lbs. @ 3,600 rpm

LT4 Applications

VIN 8th DigitYearMakeModel
62014-presentChevroletCorvette Z06
62016-presentCadillacCTS-V
62017-presentChevroletCamaro ZL1

LT4 Engine Block Specs

LT4 Block Specs
Part Number19329617
Material319-T7 Aluminum
Displacement6.2L / 376 c.i.d.
Bore Dia. 4.065 in.
Stroke3.622 in.
Deck Height9.240 in.
Bore Spacing4.400 in.
Thrust Bearing Location#3 Main, 1/2 thrust
Main Cap Style6-Bolt
Main Housing Bore Dia.2.751 in.
Cam Housing Bore Dia.Bore 1/5 = 2.346 in. Bore 2/4 = 2.326 in. Bore 3 = 2.307 in.
Cam-to-Crank Centerline4.914 in.
Oil Squirters8

LT4 Rotating Assembly

LT4 Rotating Assembly Specs
Piston MaterialForged Aluminum Alloy
Piston StyleFlat Top (with reliefs for the exhaust valve and direct injector)
Piston Volume11cc (net)
Piston Ring MaterialPVD coated top ring, Chrome second ring, Nitride Stainless oil ring.
Wrist Pin Dia.0.9431 in. (full floating)
Wrist Pin MaterialSteel (with DLC coating)
Connecting Rod MaterialPowdered Metal
Connecting Rod StyleI-Beam
Connecting Rod Length6.098 in.
Connecting Rod Housing Bore2.225 in.
Connecting Rod BoltsM9 x 1 x 43
Connecting Rod Part Number12669751
Crankshaft Material1538MV Forged Steel (with fillets)
Crankshaft Part Number (Wet Sump)12674746
Crankshaft Part Number (Dry Sump)12674743
Crankshaft Main Journal Dia.2.559 in.
Crankshaft Rod Journal Dia.2.100 in.
Reluctor Wheel58X
Harmonic BalancerAnodized aluminum hub (with iron ring)

LT4 Cylinder Heads

LT4 Cylinder Head Specs
Part Number12646959
Casting Number12646956
MaterialRotocast A356-T6 Aluminum
Combustion Chamber Volume65.47cc
Intake Port ShapeRectangle
Intake Runner Volume--
Intake Manifold Bolt PatternLT4 Specific
Exhaust Port ShapeFlat Oval
Exhaust Runner Volume--
Cylinder Head Bolt StyleTorque to Yield (TTY)
Cylinder Head Bolt Size(10) M12 x 1.75, M8 corner bolts

NOTE: Blank specifications are currently unavailable.

LT4 Camshafts

LT4 Cam Specs
Part Number12642245
Duration @ .050 in. (int./exh.)189°/223°
Valve Lift (int./exh.)0.492 in./0.551 in.
Lobe Separation Angle120°
Cam Gear Attachment1-Bolt
Cam Gear Poles4X
Active Fuel Management (AFM)Yes**
Variable Valve Timing (VVT)Yes

NOTE: **All versions used AFM with one exception — the Chevy Camaro ZL1 with manual transmission.

LT4 Valvetrain

LT4 Valvetrain Specs
Lifter StyleHydraulic Roller
Lifter Link StylePlastic Lifter Tray
Lifter Body Diameter0.842 in.
Pushrod Dimensions7.85 in. (long) x 0.342 (dia.)
Rocker Arm Mounting StylePedestal
Rocker Arm StyleDie-Cast, Roller Fulcrum
Rocker Ratio1.8
Rocker OffsetNone
Valve Spring StyleBeehive
Valve Spring ColorNatural
Intake Valve Angle12.5° / Splayed 2.61°
Exhaust Valve Angle12.0° / Splayed 2.38°
Intake Valve MaterialTitanium, Solid Stem
Intake Valve Dia.2.126 in.
Exhaust Valve MaterialSteel, Sodium Filled
Exhaust Valve Dia.1.590 in.
Timing Chain Guide StyleSpring-Loaded Tensioner

Other Key LT4 Specs

LT4 Supercharger, Throttle Body, Fuel Injector Specs & More
SuperchargerEaton 1.7L (R1740)
Supercharger7.88 in. (long) x 3.94 in. (dia.) - 160° Helix
Supercharger Drive3.1:1 drive ratio, 20,150 rpm max, 9.2-9.7 lbs. boost
Intercooler23% smaller than LS9, but 10% better heat rejection
Throttle Body87mm, 4-Bolt
Throttle ControlElectronic (Drive-by-Wire)
Fuel Injector P/N12684130
Fuel Injector Flow141 lbs./hr. (2,940 max psi)
Flex Fuel Capable (E-85)No
ComputerE92
Crankshaft Reluctor Ring58x
Camshaft Sensor LocationTiming Cover
Oil Capacity (Wet Sump)
10 qt.
Oil Capacity (Dry Sump)9.75 qt.
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