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CATEGORIES (articles) > Engines > Chevy Engines > LS Aluminium range of V8 engines

LS Aluminium range of V8 engines

The LS is Generation III and Generation IV, the latest evolution of General Motors' line of small-block V8 engines. The LS series was a clean sheet design, drawing on the heritage of the classic small-block, but is all-aluminum and has 6-bolt main bearing caps. The LS engine has been the sole powerplant of the C5 and C6 Chevrolet Corvette, and has also been used in the Pontiac GTO, the Cadillac CTS V-series, the Holden Commodore and Monaro since 1999 and the late Camaro and Firebird V8 models.

Generation III

The Generation III small-blocks replaced the LT family in 1997. These shared the same rough displacement and bore spacing (4.4 in) as their cast iron predecessors but almost everything else was changed. The bore was reduced to 3.9 in and the stroke longer at 3.62 in for greater low end torque, since the heads and intake would be designed around higher rpm applications this time around. The block was cast from aluminum (for cars) instead of iron and had a new intake and injection technology and coil-on-plug ignition. The traditional five-bolt pentagonal cylinder head pattern was replaced with a square four-bolt design, and the pistons are flat instead of domed. Even the cylinder firing order was changed.


GM LS1 engine from the Chevrolet Camaro

The LS1 shares little other than similar displacement and external dimensions with the earlier small-block V8 engines. It is an all-aluminum 5.7 L (346 in³) pushrod engine and was rated between 305 and 350 hp (228 to 261 kW) and 375 ft·lbf (508 N·m) of torque, depending on the application. However, regardless of application, the LS1s used in vehicles are widely known to be underrated from the factory, and will usually produce an actual 350hp (261kW) and 350+ lb/ft of torque (measured at the flywheel) in all of their applications (not to be confused with LS6 vehicles). Speculation is that GM did not want another vehicle to be known to be close in power to the Chevrolet Corvette, GM's performance flagship. Beginning in 2001, the LS1 received the higher-flowing intake from the LS6, and a smaller camshaft to keep power at the same level; this also allowed GM to remove the exhaust gas recirculation (EGR) system. The block is very similar to that of the higher-output LS6; beginning in 2002, some LS1 engines were actually built using the LS6 block instead. The LS1 was on the Ward's 10 Best Engines list for 1998.


  • 1997-2004 C5 Corvette base model
  • 1998-2002 Chevrolet Camaro Z28, SS
  • 1998-2002 Pontiac Firebird Formula and Trans-Am
  • 2004 Pontiac GTO
  • 1999-2005 Holden Commodore as an option
  • 1999-2005 Holden Statesman/Caprice
  • 2001-2005 Holden Monaro


GM LS6 engine in a Chevrolet Corvette Z06
LS6 can also refer to a 454 in³ Chevrolet Big-Block engine of the 1970s

The LS6 is a higher-output version of Chevrolet's small-block LS1 engine. It is an all-aluminum 5.7 L (346 in³) pushrod engine. The initial 2001 LS6 produced 385 hp (287 kW) and 385 ft·lbf (522 N·m), but the engine was modified for 2002 through 2004 to produce 405 hp (302 kW) and 400 ft·lbf (542 N·m) of torque. The LS6 was originally only used in the high-performance C5 Corvette Z06 model, with the Cadillac CTS V-Series getting the 405 hp engine later. The V-Series only retained the LS6 for two years and was then replaced with the LS2 in 2006. For 2006, the Z06 replaced the LS6 with the new 7.0L LS7.

The LS6 shares its basic block design with the GM LS1 engine, but other changes were made such as windows cast into the block between cylinders. Improved intake, a titanium exhaust, higher-lift cams, and higher compression boosts output, and a new oiling system is better suited to high lateral acceleration.

Vortec engines

The Vortec 4800, 5300, and 6000 are truck versions of the LS1 engine with different bore and stroke dimensions. The 4.8L and 6.0L versions are iron-block only, while the 5.3L has been built with both iron and aluminum blocks, depending on the application.

Generation IV

Hot on the heels of the Generation III was Generation IV. These big-bore engines are some of the largest small-blocks yet, and will quickly replace the previous generation. Displacement ranges up to 7.0 L and output to 505 hp (373 kW). Generation IV will later feature displacement on demand, a technology that allows one bank of cylinders to be deactivated. It will also offer variable valve timing. A 3-valve per cylinder design was originally slated for the LS7, which would have been a first for a pushrod engine, but the design was shelved when the same two-valve configuration as the other Generation III and IV engines proved to be sufficient to meet the goals for the LS7.


See also the Vortec 6000 L76

L76 is Holden's version of the 6.0 L Generation IV engine. It lacks the displacement on demand technology found on some versions, but meets Euro III emissions requirements. Output is 348 hp (260 kW) at 5600 rpm and 376 ft·lbf (510 N·m) at 4400 rpm.


GM LS2 engine in a 2005 Chevrolet Corvette

The LS2 is the new base engine in the Corvette. It produces 400 hp (298 kW) at 6000 rpm and 400 ft·lbf (542 N·m) at 4400 rpm from a new 6.0 L (364.3 in³) V8 based on the old LS1. It is similar to the high-performance LS6, but with an improved power peak and more torque throughout the rpm range.


  • 2005-2006 Chevrolet Corvette
  • 2005-2006 Pontiac GTO
  • 2005-2006 Chevrolet SSR
  • 2006 Chevrolet TrailBlazer SS
  • 2006 Cadillac CTS-V
  • 2004-2006 HSV GTO - Holden Special Vehicles
  • 2004-2006 HSV Clubsport - Holden Special Vehicles
  • 2004-2006 HSV Grange - Holden Special Vehicles
  • 2004-2006 HSV Maloo - Holden Special Vehicles
  • 2004-2006 HSV Senator - Holden Special Vehicles
  • 2005-2006 Vauxhall Monaro VXR


5.3 L LS4 V8 in a 2006 Chevrolet Impala SS

The LS4 is a smaller 5.3 L (325 in³) version of the Generation IV block. Though it has the same displacement as the Vortec 5300 LH6, it differs in that it has an aluminum block rather than an iron one and it used the same cylinder head as the Generation III LS6 engine.

A version of this engine is adapted for transverse front-wheel drive application. In order to fit into the smaller engine compartments designed for V-6s, in the front-wheel drive Pontiac Grand Prix GXP, for instance, the LS4 engine block had to be shortened by one inch. Displacement on Demand is also used. Output of this version is 303 hp (226 kW) and 323 ft·lbf (438 N·m).


  • 2006 Chevrolet Impala/Monte Carlo SS
  • 2006 Pontiac Grand Prix GXP


7.0 L LS7 engine in a 2006 Chevrolet Corvette Z06

The LS7 is the latest high-power LS engine. It is a 7.0 L (427.6 in³) unit, based on the Gen IV architecture. The block is changed, with a larger 4.125 in (104.9 mm) bore and longer 4.00 in (101.6 mm) stroke than the LS2. The small-block's 4.4 in (111.8 mm) bore spacing is retained, requiring pressed-in cylinder liners. The crankshaft and main bearing caps are forged steel for durability, the connecting rods are forged titanium, and the pistons are hypereutectic, possibly to keep the relatively small mass pistons in check when they thermally expand at operating temperature. The two-valve arrangement is retained, though the titanium intake valves by Del West have grown to 2.20 in (55.9 mm) and sodium-filled exhaust valves are up to 1.61 in (40.9 mm). Peak output is 505 hp (377 kW) at 6300 rpm and 470 ft·lbf (637 N·m) at 4800 rpm with a 7000 rpm redline. During GM's reliability testing of this engine in it's prototype phase, the LS7 was remarked to have been repeated tested to be 8000 rpm capable, although power was not made at that rpm level, due to the restraints of the tame street camshaft's profile and the intake manifold ability to flow required air at that engine speed.

The LS7 is hand-built by the General Motors Performance Build Center in Wixom, Michigan. Up to 15,000 LS7s will be produced each year starting in 2005. Most of these engines are installed in the Z06, but some are also sold to individuals by GM as a crate engine. It is rumored the LS7 will be the peak powerplant in the new Camaro if it makes production. It is also hinted this engine will be used in the next generation CTS V-Series. This would necessitate an increase in production.

The 7.0 L mark had already been reached by the LS-series of racing engines, famously in the 24 Hours of Le Mans Corvette C5R. GMMG Berger Camaro ZL1s made late in 2002 and GMMG Berger Dick Harrell Camaros (inspired by the Roger Penske Mark Donahue concept car) also featured variations of the 7.0 L size.


  • 2006 Corvette Z06

Holden Special Vehicles is widely tipped to use the LS7 on its 2007 GTS.

Chevrolet also had an experimental big-block engine named LS7 in the late 60's that were supposed to be in the 1970 Corvette, but it never materialized. Some LS7 heads were sold as an aftermarket product in 1971 and 1972 though.


Early reports indicate that a 6.2 L LS9 derivative is due in 2008. Displacement was a reportedly decreased for a thicker cylinder wall, to promote a stronger cylinder to deal with the rigors of possibly forced induction. A picture of this motor was seen drifting around on the internet, and it seems to be equipped with a positive displacement supercharger and is stated to produce 650 hp (485 kW).

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