Throughout the years, there have been a number of legendary powerplants to call the Corvette’s engine bay home. Of these, few have been as iconic, or well-received, as the LS platform. Through its many renditions and technological advances, the LS series of engines have been touted far and wide as offering the ultimate in raw performance potential.
Of the memorable engines featured within the LS series, one particular offering stands out for its versatility and raw ease of adaptability, over all others. The LS2, which was offered in the Corvette from 2005 to 2007, served as a testament to GM’s relentless drive toward innovation.
The History of The LS2
GM’s new LS platform first debuted in 1995, and made its initial appearance under the hood of the Corvette in 1997, serving as the powerplant for the freshly released C5. The platform itself deviated substantially from GM’s prior V8 lineup, sharing little more than its common displacement value.
By 2005, several factors culminated in the design and development of GM’s latest addition to the LS line, the LS2. The LS1 had spent a lengthy period as the Corvette’s standard powerplant. Its role within the Corvette line had remained unchanged for eight years, with only subtle upgrades and revisions taking place during its tenure.
GM was also poised to release the all-new C6, and as such, felt it only fitting to offer consumers something new and original under the hood. At the same time, design and development within the LS program had turned toward an increasing interest in fuel efficiency, making further technological advancement necessary within this realm to achieve success.
Primarily as a result of these factors, GM introduced the first engine within the LS Gen IV family, the LS2. GM touted the LS2 as featuring a newly developed engine block. However, upon further examination, it became evident that the LS2’s block was simply a redesigned rendition of the Gen III block that preceded it. It seemed that this redesign intended to make way for Active Fuel Management Technology to be added to the LS line.
Because of the Gen IV LS2 block’s similarity to the Gen III blocks of prior years, many bolt-on parts are cross-compatible between the two. The LS2 even came fitted with LS6 era cylinder heads. This level of compatibility has made the LS2 quite popular among engine builders and performance modders alike.
The LS2’s glory days proved to be short-lived, as after only three years of production, it was nixed as the Corvette’s standard engine offering, in favor of the LS3. However, the Trailblazer SS and Saab 9-7X continued to be powered by the LS2 until 2009.
LS2 Technical Specifications & Configurations
In relation to the Gen III LS engines that came before it, the LS2 featured a slightly greater displacement value of 364.1 cubic-inches, over the prior LS1. The LS2 also featured an increase in cylinder bore dimensions from 3.90 inches to 4.00 inches. This initial Gen IV small-block was capable of producing 400 horsepower at 6,000 RPM, and churning out an impressive 400 lb./ft. of torque at 4,400 RPM.
The LS2 utilized the same “243” casting heads that were featured on the LS6, though the use of sodium-filled valves was forgone in this particular application. The LS2 also made use of a smaller camshaft than that used in conjunction with the LS6.
In the realm of overall performance, the LS2 displayed a greater amount of torque throughout the entirety of its power-band, than that of the LS6. The LS2 also featured an increased compression ratio of 10.9:1, over the LS6’s 10.5:1 ratio.
There were several other changes between the LS2’s Gen IV block design, and the Gen III block design of the LS1. Some of the most notable included a relocation of the camshaft position sensor to the front of the block as opposed to its previous location in the rear, the PCV valve’s move from the valve covers to the cylinder bank valley, and a repositioning of the knock sensors to all externally accessible locations.
The LS2 also featured newly adapted exhaust manifolds, which were designed for weight reduction, and increased flow rates. Manifold wall thickness was reduced from 4mm to 3mm, leading to a ⅓ reduction in weight, and a 4% improvement in flow.
The Active Fuel Management Technology made available within the Gen IV small-block design relied upon a set of specialty collapsable lifters, a Lifter Oil Manifold Assembly, and function-specific engine controller for intelligent function. When at cruising speeds, the ECM signaled for the deactivation of four cylinders. Upon deactivation, lifters within the dead cylinders were allowed to compress, making rotational camshaft function possible, without valve actuation on affected cylinders. LS2 engines utilizing this technology carried RPO code “L76”.
LS2 Engine Specifications
- Horsepower: 400 hp @ 6,000 rpm (298 kW)
- Torque: 400 lb./ft. @ 4,400 rpm (542 N.m)
- Compression Ratio: 10.9:1
- Displacement: 364.1 cubic-inches (5.967 L)
- Cylinder Bore: 4.00 inches (101.6 mm)
- Stroke: 3.62 inch (92mm)
Vehicles Using the LS2 Engine
Though the LS2 only spent a few years in the sun, the storied engine was featured in several factory applications. The following list provides insight into which GM models carried the LS2 under the hood.
- Chevrolet C6 Corvette (2005-2007)
- Chevrolet SSR (2005-2006)
- Chevrolet Trailblazer SS (2006-2009)
- Cadillac CTS-V (2006-2007)
- Pontiac GTO (2005-2006)
- Saab 9-7X (2008-2009)
Notable LS2 Uses
Perhaps the biggest limiting factor to the LS2’s success on the track, or elsewhere, was the minimal duration of its production run. The early Gen IV engine was only used in limited factory applications for a period of 5 years. However, the LS2 did find its way into several specialized applications during its tenure.
Nascar Spec LS2 Engine
In 2007, Nascar approved the use of a spec engine built by Carl Wegner of Wegner Automotive, which was based on the LS2 platform. Wegner used many stock GM parts within his build, even retaining the use of the LS2’s block and heads, while utilizing stock dimensions for main/rod journal sizes, valve sizes, and bore/stroke.
This Nascar specific LS2 was capable of mustering 625 hp, and 520 lb./ft. of torque. The spec-based engine saw use within Nascar’s Grand National Series, and by all accounts was renowned for its stellar performance, at a fraction of the cost associated with other non-factory dimension based builds.
Holden Special LS2 Engine
Modified LS2 engines also found their way into luxury auto manufacturer Holden Special Vehicles’ E-Series line of cars. The LS2’s used were tweaked to provide a total of 412 hp, and 412 lb./ft. of torque.
Before Holden’s use of the LS2, the LS1 had been the powerplant of choice in many of the company’s models. Holden specified their switch from the LS1 to the LS2 as a necessity, due to the prior’s non-compliance with ever-tightening European emissions standards.
A Lasting Legacy
Even today, some fifteen years after its introduction, the LS2 remains in high demand by consumers across the globe. The LS2’s range of adaptability, due to the sheer volume of available bolt-on components, makes it a favorite of performance-minded engine builders worldwide. The LS2 also ushered in a new era, paving the way for future development within the Gen IV LS engine line, from which Chevrolet continued to build upon in the years that followed.
Where were these LS2 engine built?
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