LS4 Engine Specs

Here in this article, you will learn about the LS4 Engine Specs, Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More, Let’s discuss the LS4 Engine Specs, Valvetrain, performance, and Reviews.

For GM vehicles manufactured between 2005 and 2009, the LS4 engine was a Gen. 4 5.3-liter aluminium small-block motor.

The only LS engine ever installed in front-wheel-drive automobiles makes this one special.

The cylinder heads of the LS4 utilized Active Fuel Management and were designed to look like a cathedral (AFM).

Both flex-fuel (E85) capability and variable valve timing (VVT) technology were absent from the engine design.

Because of their mechanical similarity, the LS and LS-based Vortec engines from General Motors ended up in nearly every brand in the GM stable, including Chevrolet, Pontiac, GMC, Cadillac, Buick, and even Saab, Hummer, and Isuzu.

Since LS and Vortec engines are easy to find, they have become the standard for performance and swap applications.

The addition of turbochargers, superchargers, high-flow cylinder heads, intake systems, cams, and nitrous oxide to these engines can result in significant power gains.

LS4 Engine Specs

LS4 Block Specs

Casting Number 12569004
Material Aluminium
Displacement 5.3L / 325 c.i.d.
Bore Dia. 3.780 in.
Stroke 3.622 in.
Deck Height 9.240 in.
Bore Spacing 4.400 in.
Thrust Bearing Location #3 Main
Main Cap Style 6-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 Centerline 4.914 in.

LS4 Engine Ratings

Compression Ratio 10:1
Horsepower Rating 303 hp
Torque Rating 323 ft.-lbs.

LS4 Cylinder Head Specs

Casting Numbers 799, 243
Material Aluminium
Combustion Chamber Volume 65cc
Intake Port Shape Cathedral
Intake Runner Volume 210cc
Exhaust Port Shape D-Port
Exhaust Runner Volume 75cc
Intake Valve Diameter 2.000 in.
Exhaust Valve Diameter 1.575 in.
Cylinder Head Bolt Style Torque to Yield (TTY)
Cylinder Head Bolt Size (10) M11 x 2 x 100, (5) M8 x 1.25 x 45

LS4 Valvetrain Specs

Lifter Style Hydraulic Roller
Lifter Link Style Plastic Lifter Tray
Lifter Body Diameter 0.842 in.
Pushrod Length 7.385 in.
Rocker Arm Mounting Style Pedestal
Rocker Arm Style Die-Cast, Roller Fulcrum
Rocker Ratio 1.7
Rocker Offset None
Valve Spring Style Beehive
Valve Spring Color Natural
Valve Angle 15 Degrees
Intake Valve Material Steel, Solid Stem
Intake Valve Dia. 2.000 in.
Exhaust Valve Material Steel, Solid Stem
Exhaust Valve Dia. 1.575 in.
Timing Chain Guide Style
Timing Chain Guide Style
Spring Loaded Tensioner

LS4 Rotating Assembly Specs

Piston Volume 0cc
Wrist Pin Dia. 0.9431 in. (Full Floating)
Connecting Rod Material Powdered Metal
Connecting Rod Style I-Beam
Connecting Rod Length 6.098 in.
Connecting Rod Housing Bore 2.225 in.
Connecting Rod Bolts M9 x 1 x 43
Rod Part Number
Rod Casting
(Last 3 Digits)
Crankshaft Material Cast Iron
Crankshaft Part Number 12568920
Crankshaft Casting Number
(Last 3 Digits)
Crankshaft Main Journal Dia. 2.559 in.
Crankshaft Rod Journal Dia. 2.100 in.
Crankshaft Length 13mm Shorter than Standard (-10mm snout, -3mm rear flange)
Reluctor Wheel
(2005-Early 2007)
Reluctor Wheel
(Later 2007-09)
Piston Material Hypereutectic Cast Aluminum Alloy
Piston Style Flat Top

LS4 Applications

VIN 8th Digit Year Make Model
C 2005-08 Pontiac Grand Prix GXP
C 2006-07 Chevrolet Monte Carlo SS
C 2006-09 Chevrolet Impala SS
C 2008-09 Buick LaCrosse Super

Other Key LS4 Specs

Intake Manifold Part Number 12604786
Intake Manifold Car-Style (Reversed)
Intake Manifold Part Number
Intake Manifold Part Number
Throttle Body 76mm, 4-Bolt, Gold Blade (Non-standard Bolt Pattern)
Throttle Control Electronic, Drive-by-Wire
Fuel Injector Part Number 12580681
Fuel Injector Flow 30 lbs./hr. @ 58 psi
Fuel Injector Length Between O-Rings 1.73 in.
Fuel Injector Connector EV6 / USCAR
Crankshaft Reluctor Ring
(2005-Early 2007)
Crankshaft Reluctor Ring
Camshaft Sensor Location Timing Cover
Oil Pan Centred Sump
Oil Pump High Volume, 1.25 c.i./rev.

LS4 Engine Specs Review

The LS4 engine is a reliable and durable 5.3L V8 engine that produces good power and torque without sacrificing fuel efficiency. It is a good choice for both stock and modified vehicles, and it is known for its ability to be easily worked on.

Full review of YouTube video

LS4 Engine Specs FAQ

What size motor is a LS4?

General Motors LS4 is a popular option for those shopping for a large car engine.

The LS4 is the sole small block engine available in a transverse layout, and it has a displacement of 5.3 litres in a V8 configuration.

Is the LS4 engine a good engine?

Unless you’re doing a swap into an FWD vehicle or a mid-engine kit car, the LS4 isn’t the best option for an engine.

Get the thermostat set to 160 degrees before visiting the chassis dyno tuner, since this will increase the available tuning range.

What does the LS4 come in?

The LS4 was GM’s fourth-generation, 5.3-litre (L) aluminium small block engine, installed in vehicles from 2005 to 2009.

As the only LS engine ever installed in a front-wheel-drive car, it has a distinct place in history.

The LS4 employed active fuel management and had cylinder heads with a cathedral port design (AFM).

Is the LS4 a Corvette engine?

Finally, General Motors offered a 454-ci LS4 engine for the Corvette in 1973.

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