Vehicle (L77). This engine is one of the most adaptable in the LS family, as LS1, LS6, LS3, and L92/L94 cylinder heads work well on it.
LS3/L99
Introduced on the 2008 Corvette, the LS3 brought LS-based performance to an unprecedented level: 430 hp from 6.2L (376 ci). The LS3 block not only had larger bores than the LS2 but also a strengthened casting to support more powerful applications, including the LS9 supercharged engine of the Corvette ZR1. The LS3 was also the standard engine in the fifth-generation Camaro SS and was offered in the Pontiac G8 GXP. The L99 version was equipped with GM’s fuel-saving Active Fuel Management cylinder deactivation system and was standard on fifth-generation Camaro SS models equipped with an automatic transmission. A unique version of the LS3 used in some C6 Corvette Grand Sport applications incorporated a dry-sump oiling system.
LS4
Perhaps the most unique application of the LS engine in a car, the LS4 was a 5.3L version used in the front-wheel-drive Chevrolet Impala SS and Pontiac Grand Prix GXP. The LS4 had an aluminum block and unique, low-profile front-end accessory system, including a “flattened” water pump, to accommodate the transverse mounting position within the Impala and Grand Prix. It was rated at 303 hp and 323 ft-lbs of torque.
LS7
A legend in its own time. The LS7 was the standard engine in the C6 Corvette Z06 and fifth-generation Camaro Z28. Its 7.0L displacement (427 ci) made it the largest LS engine offered in production vehicles. Unlike LS1/LS6, LS2, and LS3 engines, the LS7 uses a Siamese-bore cylinder block design, which was required for its big 4.125-inch bores. Competition-proven heads and lightweight components, such as titanium rods and intake valves, made the LS7 a street-tuned racing engine with 505 hp. Chevrolet Performance’s crate engine reflects the Camaro Z28 version, which features a unique Tri-Y exhaust manifold design.
LS9
The LS9 was the 6.2L supercharged and charge-cooled engine of the C6 Corvette ZR1, rated at 638 hp. The LS9 used a strengthened 6.2L block with stronger roto-cast cylinder heads and a sixth-generation 2.3L Roots-type supercharger. Like the LS7, it used a dry-sump oiling system.
Pictured is an LSA 6.2-liter supercharged Gen IV. (Photo Courtesy General Motors)
LSA
This supercharged 6.2L engine powered the 2009–2015 Cadillac CTS-V series and the 2012–2015 Camaro ZL1. Although similar to the LS9 in design, it was built with several differences, including hypereutectic pistons versus the LS9’s forged pistons and a smaller 1.9L supercharger. It also has an eight-bolt flywheel versus the LS9’s nine-bolt pattern. The LSA has a unique charge-cooler design on top of the supercharger (with differences between the Cadillac and Camaro ZL1 applications). It was rated at 556 hp in the CTS-V and 580 hp in the Camaro ZL1. Chevrolet Performance’s crate engine reflects the Camaro ZL1 application.
Gen III and Gen IV Vortec Truck Engines
Although performance car engines have typically carried “LS” designations, truck engines built on this platform have been dubbed “Vortec.” They are generally distinguished by iron cylinder blocks and smaller displacements than car engines. Interestingly, a 5.7L Vortec “LS” engine has never been offered. Here’s a quick rundown of production LS truck engines.
4.8L: The smallest-displacement LS engine (293 ci); it uses an iron block with 3.78-inch bores and aluminum heads.
5.3L: The most common LS truck engine, it uses the same iron block with 3.78-inch bores as the 4.8L, but with a larger, 3.62-inch stroke (327 ci). Later versions equipped for Active Fuel Management and 2010-and-newer versions feature variable valve timing (cam phasing). Manufactured with iron and aluminum cylinder blocks.
6.0L: Used primarily in 3/4-ton and 1-ton trucks, the 6.0L (364 ci) uses an iron block (LY6 or L96) or aluminum block (L76) and aluminum heads with provisions for Active Fuel Management; some are equipped with variable valve timing.
6.2L: Commonly referred to by its L92, L9H, or L94 engine codes, the 6.2L (376-ci) engine uses an aluminum block and heads and incorporates advanced technology, including variable valve timing. The L92 was used primarily as a high-performance engine for the Cadillac Escalade and GMC Yukon Denali.
More About the Vortec 5.3L
With more than 10 years in service in millions of Chevy and GMC trucks, vans, and SUVs, the Vortec 5.3L engine is poised to become the classic 350 small-block of the LS engine family. They are readily available and affordable on the used engine market. Most feature iron cylinder blocks, but some have an aluminum engine block that is about 80 pounds lighter.
Adapting a 5.3L to a hot rod project is easier with Chevrolet Performance’s 5.3L controller kit (part number 19256514), which is tailored to retrofit installations by “turning off” some of the production features that are unnecessary for a vintage car, including the cylinder-deactivating Active Fuel Management. It covers 2007–2009 applications (non-cam-phased) with the following engine codes:
• LC9 (2007–2009)
• LMG (2007–2009)
• LY5 (2007–2009)
• LH8 (2008–2009)
• LMF (2008–2009)
An L94 Vortec 6.2L Gen IV is shown. (Photo Courtesy General Motors)
Chevrolet Performance LS and LSX High-Performance Crate Engines
Chevrolet Performance has offered a number of LS high-performance crate engines based on production LS engines or the racing-oriented LSX series of components, including the cast-iron LSX Bowtie Block. They include:
LS376/515: Based on the LS3, it features the “ASA Hot Cam” to help push output to 525 hp and 477 ft-lbs of torque. It is designed for a carburetor.
LS376/525: Similar to the LS376/515, this version also uses the ASA Hot Cam, along with an LS3-based induction system and port fuel injection.
LSX376-B8: An economical crate engine that uses the LSX block, LS3 rotating parts, and the LS3 cylinder heads. It is offered without an oil pan or induction system, so that it can be tailored for the project vehicle.
LSX376-B15: Designed to accommodate additional power adders, or boost up to 15 psi, includes forged pistons, forged crank, and six-bolt LSX-LS3 cylinder heads.
LSX454: The displacement of the classic big-block with an all-forged rotating assembly and LSX-LS7 six-bolt cylinder heads. It is rated at 627 hp with a carburetor and 580 with an LS7 fuel-injection system.
Excellent airflow characteristics of the basic LS cylinder head design greatly exploit the benefits of forced induction, as air is easily and quickly moved through the engine. Because of this, a higher-capacity supercharger or larger turbo is often used, when compared to older, previous-generation Chevy small-block designs, to fulfill the airflow capability of a free-flowing LS engine.
