LS Engines

LS1 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

LS1 Engine in a 1997 Chevy Corvette

The 5.7L GM LS made its first appearance in the 1997 Chevy Corvette. (Image/LSX Magazine)

Mechanically similar, General Motors’ LS and LS-based Vortec engines wound up on almost every branch of the GM family tree: Chevy, Pontiac, GMC, Cadillac, Buick—heck, even Saab, Hummer, and Isuzu got some LS love.

Since LS and Vortec engines are so common, they’ve become the go-to performance and swap engines of the modern era.

These motors are capable of making a lot of horsepower, and respond well to upgrades like turbos, superchargers, high-flow cylinder heads, intake systems, cams, and nitrous oxide.

[Looking to upgrade your LS1 engine? Check out LS1 Engine Upgrade Guide: Expert Advice for LS1 Mods to Maximize Performance.]

The aftermarket is strong, crate engines are available, and used motors are often cheaply sourced through junkyards.

[Trying to find an LS engine? Check out Part 1 and Part 2 of our LS Spotter’s Guide.]

Summit Racing has created a series of comprehensive guides for each engine in the LS family, so engine builders and tuners can have a handy reference for their projects.

The first engine on the list is the first GM LS—the 5.7L LS1 that appeared in the 1997 Chevy Corvette.

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

GM LS1 Engine Specs

The LS1 is the original Gen. 3 small block engine used in cars from 1997-2004. The information listed here is for the stock engine.

LS1 Performance Specifications

Engine Ratings
Compression Ratio10.2:1
Horsepower Rating305-350 hp
Torque Rating335-365 ft./lbs.

LS1 Applications

VIN 8th DigitYearMakeModel
G1998-2002ChevyCamaro (Z28 / SS)
G1998-2002PontiacFirebird / Trans Am

LS1 Engine Blocks

LS1 Block Specs
Casting Numbers12550592, 12559846, 12559090, 12560621, 12562174, 12560629, 12559378, 12559846, 12560626, 12561166, 12561168
MaterialAluminum - Semi Permanent Mold
Displacement5.7L / 346 c.i.d.
Bore Dia. 3.898 in.
Stroke3.622 in.
Deck Height9.240 in.
Bore Spacing4.400 in.
Thrust Bearing Location#3 Main
Main Cap Style6-Bolt
Main Housing Bore Dia.2.751 in.
Cam Housing Bore Dia. (2002-03)Bore 1/5 = 2.326, Bore 2/4 = 2.317, Bore 3 = 2.307
Cam Housing Bore Dia. (2004-07)Bore 1/5 = 2.346, Bore 2/4 = 2.326, Bore 3 = 2.307
Cam-to-Crank Centerline4.914 in.

LS1 Rotating Assembly

LS1 Rotating Assembly Specs
Piston MaterialHypereutectic Cast Aluminum Alloy M124
Piston StyleFlat Top
Piston Volume0cc
Wrist Pin Dia. (1997-2004)0.9449 in (Press Fit)
Connecting Rod MaterialPowdered Metal
Connecting Rod StyleI-Beam
Connecting Rod Length6.098 in.
Connecting Rod BoltsM9 x 1 x 43
Crankshaft MaterialCast Iron
Crankshaft Main Journal2.559 in.
Crankshaft Rod Journal2.100 in.
Reluctor Wheel24x
Flexplate/Flywheel Mounting Flange0.857 in.

LS1 Cylinder Heads

LS1 Cylinder Head Specs
1997-1998 Casting Numbers (Perimeter Valve Cover Bolts)10215339, 12550592, 12558806
1999-2004 Casting Numbers (Center Valve Cover Bolts)12559853, 12558805, 12560621, 12562174, 12564241
Combustion Chamber Volume67cc
Intake Port ShapeCathedral
Intake Runner Volume200cc
Exhaust Port ShapeOval
Exhaust Runner Volume70cc
Intake Valve Diameter2.000 in.
Exhaust Valve Diameter1.550 in.
Cylinder Head Bolt StyleTorque to Yield (TTY)
Cylinder Head Bolt Size (1997-2003)(8) M11 x 2 x 155, (2) M11 x 2 x 100, (5) M8 x 1.25 x 45
Cylinder Head Bolt Size (2004)(10) M11 x 2 x 100, (5) M8 x 1.25 x 45

LS1 Cam Specifications

YearModelInt. Duration @ .050Exh. Duration @ .050Int. LiftExh. Lift
Lobe Separation
1998-2000Camaro Firebird1982090.4980.497119.5
2001-02Camaro Firebird1962080.4670.479116

LS1 Valvetrain

LS1 Valvetrain Specs
Lifter StyleHydraulic Roller
Lifter Link StylePlastic Lifter Tray
Lifter Body Diameter0.842 in.
Pushrod Length7.385 in.
Rocker Arm Mounting StylePedestal
Rocker Arm StyleDie-Cast, Roller Fulcrum
Rocker Ratio1.7
Rocker OffsetNone
Valve Spring StyleBeehive
Valve Spring ColorNatural
Valve Spring Pressure70 lbs. Seat / 220 lbs. Open
Valve Angle15 Degrees
Intake Valve MaterialSteel - Solid Stem
Intake Valve Dia.2.000 in.
Exhaust Valve MaterialSteel - Solid Stem
Exhaust Valve Dia.1.550 in.

Other Key LS1 Specs

Throttle Body, Fuel Injectors, Oil Pan Specs & More
Intake ManifoldLS1
Throttle Body78mm, 3-Bolt
Throttle Control, CorvetteDrive-by-Wire
Throttle Control, GTO, Camaro/FirebirdThrottle Cable
Fuel Injector Flow, 1997-9829.6 lbs.
Fuel Injector Flow, 1999-200027.3 lbs.
Fuel Injector Flow, 2001-0430 lbs.
Fuel Injector Length (between O-Rings)2.5 in.
Fuel Injector ConnectorEV1
Crankshaft Reluctor Ring24x
Camshaft SensorRear Mount, 1x on cam
Oil Pan, CorvetteBatwing Rear Sump
Oil Pan, Camaro/FirebirdRear Sump
Oil Pan, GTOFront Sump
Oil PumpStandard Volume

The data for this article originally appeared in this Chevy LS1 Engine Specs article at Summit Racing’s searchable database of FAQ tech info. Go there and search “LS engines” for a comprehensive collection of LS engine tech information.

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  3. All the Australia v8 Holden commodore’s and the muscle cars are LS powered .
    Starting in 1997 ls1 5.7 L and ending up in 2017 with the custom LS9 6.2 L supercharged. (specially designed for the VF Holden Commodore GTS W1.

    • Any one has a list of block casting numbers for the Holden & the Lumina’s LS1 engines?

      I got a casting number 12561163, properly from a Lumina but can’t get any specs…

      Carsten, Dubai
      United Arab Emirates.

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