General Motors LS-based small-block engine

The brainchild of Chevrolet chief engineer Ed Cole, the first generation of the Chevrolet small-block engine was first unveiled in the 1955 Chevrolet Corvette and Chevrolet Bel Air, both powered by the "Turbo-Fire." The 265 Turbo-Fire distinguished itself from other engines of the era such as Cadillac's 331 series of the late 1940s and early 1950s by reducing the size and weight of various components within the engine; a compact engine block combined with a light valvetrain gave the Turbo-Fire a weight reduction compared to the inline-sixes (despite having two more cylinders) that initially powered the first generation of the Corvette, alongside a significant horsepower increase of 25%. This contributed to lowering the Corvette's from 11 seconds to 8.7. Nicknamed the "Mighty Mouse," the Turbo-Fire soon became popular within the hot rodding community too, along with scoring wins in stock car racing. 1992 saw the second generation of Chevrolet small-block hit the market in that year's Chevrolet Corvette in the form of the LT1 small-block. It featured a new ignition system, reverse-flow cooling (cooling the cylinder heads first), and new engine block, but the valvetrain and engine mounts were carried over in order to maintain a degree of compatibility with the previous generation. Other modifications such as a better flowing intake manifold and cylinder heads gave the LT1 a power output of . Approval for the Gen III was granted in May 1992, after a seat-of-the-pants decision made by General Motors executives who went for a drive in two Corvettes—one equipped with a traditional pushrod engine and one with a newer dual overhead camshaft engine. Tom Stephens, then-executive director of General Motors Powertrains, was the man in charge of the project. Stephens had the task of designing an engine that was not only more powerful than the previous small-block iterations, but one that could also deliver better fuel economy and meet emissions standards. Work began in 1993, shortly after the release of the LT1 Gen II engine. A small team hand-picked from the Advanced Engineering department of General Motors was assembled to do much of the initial design work, with initial prototypes hitting test benches by the winter of 1993. Stephens also recruited Ed Koerner, a former NHRA record holder, to help with much of the hands-on work, while Stephens focused on project management issues. == Design ==

All three generations are overhead valve engines, otherwise known as pushrod engines. Overhead valve engines have the valves mounted above the cylinder head, with a pushrod and rocker arm allowing a block-mounted camshaft to activate the valves. The advantages of an engine configuration like this (as opposed to an overhead camshaft engine) is that since the camshaft is located within the engine valley, a pushrod engine will be shorter in height compared an overhead camshaft engine. Another advantage is that there are fewer mechanical components such as timing chains and extra camshafts, which increases reliability by keeping the engine simple. configuration that would typically be found in a LS-based overhead valve small-block. Lobes of a rotating camshaft transmit upward motion through valve lifters to pushrods, which open valves via downward motion transferred to them by a rocker arm. All three generations were outfitted with either aluminum or cast iron engine blocks, with all passenger car engine blocks being aluminum, whereas truck engine blocks could be either material. Every single engine was also fitted with aluminum cylinder heads, except for the 1999 and 2000 model year of the LQ4, which were cast iron. Other modifications to the cylinder heads included a redesign to include significantly better airflow, with evenly spaced exhaust and intake valves. Another feature across all generations was the bore spacing and pushrods, the former of which is also in use in the Chevrolet Gemini small-block engine. The use of aluminum allowed for further weight reduction; the 1997 LS1 was almost lighter than previous cast-iron small-block iterations. Other modifications include long runner intake manifolds, powder-forged connecting rods and the introduction of six-bolt main bearings (as opposed to two or four on the previous generations). Long runner intake manifolds in the LS series increases the airflow into the cylinders at low revolutions, increasing torque production at lower revolutions. Truck applications of the LS engine have even longer intake manifolds, being approximately taller than passenger car manifolds. Most engines were also fitted with hypereutectic pistons, Powder-forging involves sintering a specific mixture of metals and non-metals which have been compressed in a forming press. The mixture is then quickly transferred into a traditional die cavity in a forging press and is pressed once then cooled. Powder-forging is also more cost-effective compared to traditional die forging, reducing the amount of tooling required to trim inconsistencies in hot-forged connecting rods. Stronger than the forged steel connecting rods of the previous two generations, powder-forged connecting rods have been fitted to every LS and LT engine except for the LS7. ==Generation III (1997–2007)==

The Generation III small-block V8 is a "clean sheet" General Motors design produced from 1997 to 2007, which replaced the Chevrolet Generation I and Generation II engine families derived from the longstanding Chevrolet small block V8 produced between 1954 and 2003. Like the previous two generations, the Buick and Oldsmobile small blocks, the Gen III/IV can be found in many different brands. The engine blocks were cast in aluminum for car applications, and iron for most truck applications (notable exceptions include the Chevrolet TrailBlazer SS, Chevrolet SSR, and a limited run of Chevrolet Silverado/GMC Sierra extended-cab standard-box 4WD trucks). The architecture of the LS series makes for an extremely strong engine block with the aluminum engines being nearly as strong as the iron generation I and II engines. The LS engine also used coil-near-plug style ignition to replace the distributor setup of all previous small-block based engines. The traditional five-bolt pentagonal cylinder head pattern was replaced with a square four-bolt design (much like the 1964–1990 Oldsmobile V8), and the pistons are of the flat-topped variety (in the LS1, LS2, LS3, LS6, LS7, LQ9, and L33), while all other variants, including the new LS9 and LQ4 truck engine, received a dished version of the GM hypereutectic piston. The cylinder firing order was changed to 1-8-7-2-6-5-4-3 so that the LS series now corresponds to the firing pattern of other modern V8 engines (for example the Ford Modular V8). 3.898 in. bore blocks (1997–2005) The first of the Generation IIIs, the LS1 was the progenitor of the new architecture design that would transform the entire V8 line and influence the last of the big-blocks. 5.7 L The Generation III 5.7L (LS1 and LS6) engines share little other than similar displacement, external dimensions, and rod bearings, with its predecessor (LT1). It is an all-aluminum pushrod engine with a bore and stroke of . LS1 The LS1 Was introduced in the 1997 Corvette, and rated at at 5,600 rpm and at 4,400 rpm. After improvements to the intake and exhaust manifolds in 2001, the rating improved to and ( for manual-transmission Corvettes. The LS1 was used in the Corvette from 97 to 04. It was also used in 98-02 GM F-Body (Camaro & Firebird) cars with a rating of over , which was rumored to be conservative. The extra horsepower was claimed to come from the intake ram-air effect available in the SS and WS6 models. In Australia, continuous modifications were made to the LS1 engine throughout its lifetime, reaching 382 hp/376 ft-lb in the HSV's VYII series, and a Callaway modified version named "C4B" was fitted to HSV GTS models producing and of torque. Applications: LS6 The LS6 is a higher-output version of GM's LS1 engine and retains the same capacity. The initial 2001 LS6 produced and , but the engine was modified for 2002 through 2004 to produce and of torque. The LS6 was originally only used in the high-performance C5 Corvette Z06 model, with the Cadillac CTS V-Series getting the engine later. The V-Series used the LS6 for two years before being replaced by the LS2 in 2006. For 2006, the Z06 replaced the LS6 with the new LS7. The LS6 shares its basic block architecture with the GM LS1 engine, but other changes were made to the design such as windows cast into the block between cylinders, improved main web strength and bay to bay breathing, an intake manifold and MAF-sensor with higher flow capacity, a camshaft with higher lift and more duration, a higher compression ratio of 10.5:1, sodium-filled exhaust valves, and a revised oiling system better suited to high lateral acceleration. LS6 intake manifolds were also used on all 2001+ LS1/6 engines. The casting number, located on the top rear edge of the block, is 12561168. The SSC Ultimate Aero TT also utilized the LS6 block, albeit with an enlarged displacement of and the addition of two turbochargers. Applications: 3.78 in. bore blocks (1999–2007) The 4.8L and the 5.3L are smaller truck versions of the LS1 and were designed to replace the 305 and the 350 in trucks. The 4.8L and 5.3L engines share the same Gen III LS-series engine block and heads (upper end) and therefore, most parts interchange freely between these engines and other variants in the LS family. 4.8L LR4 The Vortec 4800 LR4 (VIN code "V") is a Generation III small block V8 truck engine. Displacement is with a bore and stroke of . It is the smallest of the Generation III Vortec truck engines. The LR4 engines in 1999 produced while the 2000 and above models made and all have a torque rating between , depending on the model year and application. The 2005–2006 models made and . The LR4 was manufactured at St. Catharines, Ontario, and Romulus, Michigan. It uses flat-top pistons. Applications: 5.3 L The Vortec 5300, or LM7/L59/LM4, is a V8 truck engine It is a longer-stroked by version of the Vortec 4800 and replaced the L31. L59 denoted a flexible-fuel version of the standard-fuel LM7 engine. Displacement is from a bore and stroke of . Vortec 5300s were built in St. Catharines, Ontario, and Romulus, Michigan. The aluminum block variants, the LM4 and the L33, share the same displacement, but instead use an aluminum block with cast-in cylinder liners, much like the LS1. LM7 The Vortec 5300 LM7 (VIN code 8th digit "T") was introduced in 1999. The "garden variety" Generation III V8 has a cast-iron block and aluminum heads. The 1999 LM7 engine produced and of torque. The 2000–2003 engines produced and of torque. The 2004–2007 engines produced and of torque. The stock cam specifications at .050 lift are: 190/191 duration, .466/.457 lift, 114 LSA, 112/116 timing. Applications: L59 The Vortec 5300 L59 (VIN code "Z") is a flexible-fuel version of the LM7. The 2002–2003 L59 made and , while the 2004–2007 L59 made and . Applications: LM4 The Vortec 5300 LM4 (VIN code "P") is an aluminum block version of the LM7, and had a short production life, as did the specific vehicles in which LM4s are found. LM4s made and . The LM4 and LM7 should not be confused with the L33, described below. Applications: L33 The Vortec 5300 L33 (VIN code "B") was marketed as the Vortec 5300 HO. While it used the same aluminum block as was used in the LM4, the L33 included some major differences from the LM4, resulting in higher output than the LM4 and LM7. Instead of the LM4's dished pistons, the L33 used the 4.8L's flat top pistons. It also used 799 cylinder heads, identical to 243 castings found on LS6s and LS2s, lacking only LS6-spec valve springs and lightweight valves. This combination raised the compression from 9.5:1 to 10.0:1. The L33 also used a unique camshaft not shared with any other engine, with the specifications at .050 duration being: 193 duration, .482 lift, 116 LSA. As a result, power increased by , to and . It was available in extended-cab standard-bed 4WD pickup trucks. Only 25% of 2005 Chevrolet/GMC full-size pickup trucks had an L33 engine. Applications: 4.00 in. bore blocks (1999–2007) The 6.0 L is a larger version of the LS engine. 6.0 L blocks were cast of iron, designed to bridge the gap between the new small blocks and big blocks in truck applications. There were two versions of this engine: LQ4 and LQ9, the latter being more performance oriented. 6.0 L The Vortec 6000 is a V8 truck engine. Displacement is from a bore and stroke of . It is an iron/aluminum (1999 and 2000 model year engines had cast iron heads) design and produces and . LQ4 The Vortec 6000 LQ4 (VIN code "U") is a V8 truck engine. It produces and . LQ4s were built in Romulus, Michigan, and Silao, Mexico. Applications: LQ9 The Vortec HO 6000 or VortecMAX (VIN code "N") is a special high-output version of the Vortec 6000 V8 truck engine originally designed for Cadillac in 2002. This engine was renamed as the VortecMAX for 2006. It features high-compression (10:1) flat-top pistons for an extra and , bringing output to and . Vehicles fitted with the LQ9 were backed by either a 3.73:1 (Escalade) or 4.10:1 (pickups) rear axle ratio. LQ9s were built only in Romulus, Michigan. ==Generation IV (2005–2020)==

In 2004, the Generation III was superseded by the Generation IV. This category of engines has provisions for high-displacement ranges up to and power output to . Based on the Generation III design, the Generation IV was designed with displacement on demand in mind, a technology that allows every other cylinder in the firing order to be deactivated. It can also accommodate variable valve timing. A three-valve-per-cylinder design was originally slated for the LS7, which would have been a first for a GM pushrod engine, but the idea was shelved owing to design complexities and 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. 4.00 in. bore blocks (2005–2020) This family of blocks was the first of the generation IV small block with the LS2 being the progenitor of this family and generation. This family of blocks has seen a wide range of applications from performance vehicles to truck usage. 6.0 L The Generation IV 6000 is a V8 engine that displaces from a bore and stroke of . It features either a cast iron or aluminum engine block with cast aluminum heads. Certain versions feature variable cam phasing, Active Fuel Management, and flex-fuel capability. LS2 :LS2 can also refer to the 1973–1974 Super Duty Pontiac V8 engine :LS2 can also refer to the 1985 Oldsmobile Diesel V6 engine. The LS2 was introduced as the Corvette's new base engine for the 2005 model year. It also appeared as the standard powerplant for the 2005–2006 GTO. It produces at 6000 rpm and at 4400 rpm from a slightly larger displacement of . It is similar to the high-performance LS6, but with improved torque throughout the rpm range. The LS2 uses the "243" casting heads used on the LS6 (although without the sodium-filled valves), a smaller camshaft, and an additional . The compression of the LS2 was also raised to 10.9:1 compared to the LS1s' 10.25:1 and the LS6s' 10.5:1. The LS2 in the E-series HSVs are modified in Australia to produce and of torque. The LS2 in the Chevrolet Trailblazer SS and the Saab 9-7X Aero are rated at (2006–2007) or (2008–2009) and of torque due to a different (sometimes referred to as a "truck") intake manifold that produces more torque at lower rpms. The LS2 is also used as the basis of the NASCAR Specification Engine that is used as an optional engine in NASCAR's Camping World Series East and West divisions starting in 2006, and starting in 2010 may also be used on tracks shorter than two kilometers (1.25 miles) in the Camping World Truck Series. A version of the NASCAR V8 cylinder block cast in compacted graphite iron by Grainger & Worrall won the UK's Casting of the Year Award 2010. • 2005–2007 Chevrolet Corvette • 2005–2006 Chevrolet SSR • 2006–2009 Chevrolet TrailBlazer SS • 2006–2007 Cadillac CTS-V • 2005–2008 Holden Monaro family: • 2005–2006 HSV Coupé GTO • 2005–2006 HSV SV6000 • 2005–2008 HSV Clubsport R8, Maloo R8, Senator Signature, and GTS • 2005–2008 HSV Grange • 2005–2006 Pontiac GTO (peak power at 5200 rpm, peak torque at 4000 rpm) • 2005–2006 Vauxhall Monaro VXR • 2007–2009 Vauxhall VXR8 • 2008–2009 Saab 9-7X Aero L76 The L76 is derived from the LS2, and like the LS2 it features an aluminum engine block. However, the L76 does feature Active fuel management (AFM). While the displacement on demand technology was disabled on Holdens, this feature is enabled on the 2008 Pontiac G8 GT and subsequently refitted in the 2009 model Holdens with AFM enabled, but only on models fitted with the 6L80 Automatic Transmission. The engine also meets Euro III emissions requirements. Output is at 5600 rpm and at 4400 rpm for the Holden variant, and and for the G8 GT. The Vortec 6000 or new VortecMAX version is based on the Holden L76 engine, and features variable cam phasing, along with Active Fuel Management. It can be considered the replacement for the Generation III LQ9 engine. It produces at 5400 rpm and at 4400 rpm. Production of the truck-spec L76 started in late 2006, and it was only available with the new body style Silverado and Sierra, as well as the then-new Suburban. The final year for the truck-spec L76 was 2009 for all three applications; it was replaced by the 6.2L L9H engine for MY 2010 in the pickup trucks. • 2006 Holden VZ Commodore – those built from February 2006 until July 2006 (the release of the VE series). • 2006 Holden WL Statesman/Caprice – those built from February 2006 until September 2006 (the release of the WM series). • 2008–2009 Pontiac G8 GT • 2008–2010 Holden VE Commodore (automatic only) • 2008–2010 Holden VE Ute (automatic only) • 2008–2010 Holden WM Statesman/Caprice • 2007–2009 Chevrolet Suburban 1500 • 2007–2009 Chevrolet Avalanche • 2007–2009 Chevrolet Silverado 1500 • 2007–2009 GMC Sierra 1500 • 2007–2009 GMC Yukon XL • 2020 Ginetta Akula L98 The L98 is a slightly modified version of the L76, specific to Holden vehicles. Since Holden did not use the displacement on demand technology of the L76, some redundant hardware was removed to form the L98. Power increased to at 5700 rpm and at 4400 rpm. • 2006–2013 Chevrolet Caprice • 2006–2007 Holden VZ Ute • 2006–2010 Holden VE Commodore (manual only from 2008 to 2010) • 2006–2009 Holden VE Calais • 2006–2010 Holden VE Ute (manual only from 2008 to 2010) • 2006–2008 Holden WM Statesman/Caprice L77 : L77 can also refer to the 455 Oldsmobile large crank journal engine. L77 engines were released in the Holden Commodore Series II VE range in both manual and automatic transmissions, along with the Chevrolet Caprice PPV (police car). The L77 differs from the L76 with its inclusion of Flex-fuel capability, allowing it to run on E85 fuel. The L77 is rated at and of torque in the manual Commodore SS and SS-V, in automatic Commodores it is rated at and of torque. Applications: • 2010–2013 Holden VE II Commodore • 2013–2015 Holden VF Commodore • 2010–2013 Holden VE II Ute • 2013–2015 Holden VF Ute • 2010–2013 Holden WM Caprice • 2013–2015 Holden WN Caprice • 2011–2017 Chevrolet Caprice LY6 The LY6 is a Generation IV small-block V8 truck engine with a cast-iron block. It shares the same bore and stroke as its LQ4 predecessor. Like other Gen IV engines, it features variable valve timing. It generated at 5,600 rpm and of torque at 4,400 rpm using "regular" gas, or ~87 octane. Redline is 6,000 rpm and the compression ratio is 9.6:1. This engine uses L92 / LS3 style rectangle port cylinder heads, though without the sodium-filled exhaust valves of the LS3. Applications: • 2007–2009 Chevrolet Silverado 2500HD/3500HD • 2007–2009 GMC Sierra 2500HD/3500HD • 2007–2013 Chevrolet Suburban 2500 • 2007–2013 GMC Yukon XL 2500 • 2008–2009 Chevrolet Express/GMC Savana 2500/3500/4500 L96 The L96 is essentially identical to its predecessor, the LY6. The primary difference is that the L96 is flex-fuel capable, while the LY6 is not. Applications: • 2010–2019 Chevrolet Silverado 2500HD/3500HD • 2010–2019 GMC Sierra 2500HD/3500HD • 2010–2013 Chevrolet Suburban 2500 • 2010–2013 GMC Yukon XL 2500 • 2016–2020 Chevrolet Suburban 3500HD • 2010–2020 Chevrolet Express/GMC Savana 2500/3500/4500 LFA The LFA (VIN code "5") is a Generation IV small-block V8 truck engine. The LFA variant is used in the GM's "two-mode" hybrid GMT900 trucks and SUVs, and is an all-aluminum design. It has a 10.8:1 compression ratio and produces at 5100 rpm and at 4100 rpm. In 2008, this engine was selected by Wards as one of the 10 best engines in any regular production vehicle. Applications: • 2008–2009 Chevrolet Tahoe Hybrid • 2008–2009 GMC Yukon Hybrid • 2008–2009 Cadillac Escalade Hybrid • 2008–2009 Chevrolet Silverado Hybrid • 2008–2009 GMC Sierra Hybrid LZ1 The LZ1 is almost entirely based on its predecessor, the LFA, but with some revisions, such as including up-integrated electronic throttle control, long-life spark plugs, GM's Oil Life System, Active Fuel Management, and variable valve timing. It has the same compression ratio and power/torque ratings as its predecessor. Applications: • 2010–2013 Chevrolet Tahoe Hybrid • 2010–2013 GMC Yukon Hybrid • 2010–2013 Cadillac Escalade Hybrid • 2010–2013 Chevrolet Silverado Hybrid • 2010–2013 GMC Sierra Hybrid 3.78 in. bore blocks (2005–2017) This family of blocks is an updated version of its Generation III predecessor with Generation IV updates and capabilities. Applications of this family were mainly for trucks but did see some mild usage (with some modifications) in front-wheel-drive cars. 4.8 L LY2 The Vortec 4800 LY2 (VIN code "C") is a Generation IV small-block V8 truck engine. Like its LR4 predecessor, it gets its displacement from a bore and stroke of . The smallest member of the Generation IV engine family is unique in that it is the only member used in trucks that does not feature variable valve timing; it also lacks Active Fuel Management. It has a cast-iron block. Power output is and torque is . Applications: • 2008–2009 Chevrolet Express/GMC Savana 2500/3500 • 2007–2009 Chevrolet Silverado 1500 • 2007–2009 Chevrolet Tahoe • 2007–2009 GMC Sierra 1500 • 2007–2009 GMC Yukon L20 The Vortec 4800 L20 makes more power and features variable valve timing. The system adjusts both intake and exhaust timing but does not come with Active Fuel Management. The L20 has a cast-iron block and power output is while torque is . The Vortec 4800 base engines were dropped from the Chevrolet Tahoe and GMC Yukon in favor of the 5300 with Active Fuel Management. Applications: • 2010–2017 Chevrolet Express/GMC Savana 2500/3500 • 2010–2013 Chevrolet Silverado 1500 • 2010–2013 GMC Sierra 1500 5.3 L The Generation IV 5.3L engines share all the improvements and refinements found in other Generation IV engines. Eight versions of the Gen IV 5.3L engine were produced: three iron blocks (LY5, LMG, and LMF) and five aluminum blocks (LH6, LH8, LH9, LC9, and LS4). All versions featured Active Fuel Management except for the LH8, LH9, and LMF. LH6 The Vortec 5300 LH6 (VIN code "M") with Active Fuel Management replaced the LM4 for 2005, and was the first of the Generation IV small-block V8 truck engines to go into production. The LH6 produced and . It is the aluminum block counterpart to the LY5. Applications: • 2005–2009 Chevrolet TrailBlazer including EXT (through 2006) • 2005–2009 GMC Envoy Denali • 2005–2006 GMC Envoy XL • 2005 GMC Envoy XUV • 2005–2007 Buick Rainier • 2005–2009 Saab 9-7X • 2005–2007 Isuzu Ascender • 2007–2009 Chevrolet Silverado 1500 • 2007–2009 GMC Sierra 1500 LS4 :LS4 can also refer to a Chevrolet Big-Block engine of the 1970s SS The LS4 is a version of the Generation IV block. Though it has the same displacement as the Vortec 5300 LY5, it features an aluminum block instead of iron, and uses the same cylinder head casting as the Generation III LS6 engine. The LS4 is adapted for transverse front-wheel drive applications, with a bellhousing bolt pattern that differs from the rear-wheel-drive blocks (so as to mate with the 4T65E). According to GM, "the crankshaft is shortened at the flywheel end and at the accessory drive end – to reduce the length of the engine compared to the 6.0 L. All accessories are driven by a single serpentine belt to save space. The water pump is mounted remotely with an elongated pump manifold that connects it to the coolant passages. Revised oil pan baffles, or windage trays, are incorporated into the LS4 to ensure that the oil sump stays loaded during high-g cornering." Active Fuel Management is also used. Output of this version is (300 hp on LaCrosse Super) and . Applications: • 2005–2008 Pontiac Grand Prix GXP • 2006–2009 Chevrolet Impala SS • 2006–2007 Chevrolet Monte Carlo SS • 2008–2009 Buick LaCrosse Super LY5 Introduced in 2007, the Vortec 5300 LY5 (VIN code "J") is the replacement for the LM7 Generation III engine. For SUV applications, it is rated at and of torque, while for pickup truck applications, it is rated at at 5200 rpm and at 4000 rpm. Applications: • 2007–2009 Chevrolet Avalanche • 2007–2009 Chevrolet Silverado 1500 • 2007–2009 Chevrolet Suburban 1500 • 2007–2009 Chevrolet Tahoe • 2007–2009 GMC Sierra 1500 • 2007–2009 GMC Yukon • 2007–2009 GMC Yukon XL 1500 LC9 The Vortec 5300 LC9 (VIN code "3" or "7") is the aluminum block flex-fuel version of the LH6, and is found in 4WD models. SUV applications are rated at at 5400 rpm and at 4000 rpm. Pickup truck applications are rated at at 5300 rpm and at 4000 rpm. Applications: • 2007–2013 Chevrolet Avalanche • 2007–2013 Chevrolet Silverado 1500 • 2007–2014 Chevrolet Suburban 1500 • 2007–2014 Chevrolet Tahoe • 2007–2013 GMC Sierra 1500 • 2007–2014 GMC Yukon • 2007–2014 GMC Yukon XL 1500 LH8 The LH8 was introduced in 2008 as the V8 option for the Hummer H3. It was the simplest, most basic 5.3L V8 of its family, lacking any special technologies. Also known as the Vortec 5300, the LH8 was available in the H3 and GM mid-size pickups through 2009. The LH8 is a variant of the 5.3L Gen IV small-block V8 modified to fit in the engine bay of the GMT345 SUV and GMT355 trucks. It produces at 5200 rpm and at 4000 rpm. It has a displacement of and a compression ratio of 9.9:1. Applications: • 2008–2009 Hummer H3 Alpha • 2009 Chevrolet Colorado/GMC Canyon LH9 In 2010, the LH8 was replaced by the LH9. The LH9 was upgraded with Variable Valve Timing (VVT) and flex-fuel capability (but not Active Fuel Management). The Vortec 5300 LH9 produces at 5200 rpm and at 4000 rpm. It has a displacement of . Applications: • 2010 Hummer H3 Alpha • 2010–2012 Chevrolet Colorado/GMC Canyon LMF Introduced in 2008, the LMF is a low-tech LY5, used in the lower-volume half-ton vans that still used the 4L60-E 4-speed automatic, lacking Active Fuel Management. The LMF features variable valve timing. Applications: • 2008–2014 Chevrolet Express 1500 • 2008–2014 GMC Savana 1500 4.125 in. bore blocks (2006–2017) Inspired by the LS1.R in size and performance goals, this family of blocks was designed for race-oriented performance. The only engine with this bore size that was used in a production vehicle is the LS7 with the LSX being only for aftermarket use. One unique feature of this family is that the cylinders are siamesed, no water passages between neighboring cylinders. This was done to increase both bore size and block strength. 7.0 L LS7 :LS7 can also refer to a 454 over-the-counter 460+ hp high compression engine Chevrolet Big-Block engine of the 1970s The LS7 is a engine based on the Gen IV architecture. The block is changed, with sleeved cylinders in an aluminum block with a larger bore of and longer stroke of than the LS2. The small-block's 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. The two-valve arrangement is retained, though the titanium intake valves by Del West have grown to and sodium-filled exhaust valves are up to . Peak output is at 6300 rpm (72.0 BHP/L) and of torque at 4800 rpm with a 7000 rpm redline. During GM's reliability testing of this engine in its prototype phase, the LS7 was remarked to have been repeatedly tested to be 8000 rpm capable, although power was not recorded at that rpm level, because of the constraints of the camshaft's hydraulic lifters and the intake manifold ability to flow required air at that engine speed. The LS7 was hand-built by the General Motors Performance Build Center in Wixom, Michigan. Most of these engines are installed in the Z06, some are also sold to individuals by GM as a crate engine. The 2014 and 2015 Z28 were the only Camaros to receive the 427 LS7. As of early 2022, the LS7 is no longer being supplied as a crate engine, with Chevrolet intending to fulfill all current orders until inventory is depleted. After an extensive engineering process over several years, Holden Special Vehicles fitted the LS7 to a special edition model: the W427. The HSV-tuned engine produced at 6500 rpm and at 5000 rpm of torque. It was unveiled at the Melbourne International Motor Show on February 29, 2008, and went on sale in August 2008. The first Australian car to be fitted with this engine, however, was the CSV GTS of 2007, which was claimed to have a power output of and . Applications: • 2006–2013 Chevrolet Corvette Z06 • 2008–present Spada Codatronca • 2008–2009 HSV W427 • 2009–2016 Zenvo ST1 • –2016 Ultima GTR • 2013 Corvette 427 Convertible • 2013 Mazzanti Evantra Millecavalli • 2014–2015 Chevrolet Camaro Z/28 • 2015 Exotic Rides W70 • 2015–present SIN R1 550 • 2015–present Ultima Evolution • 2020–present Hennessey Venom F5 • Vertical Hummingbird 300LS LS427 The LS427 is a engine based on the LS7 and introduced in June 2020. It was designed only as a crate engine to provide increased power and simplified installation for aftermarket and restomod applications. It did not appear in any production vehicles. Unlike the LS7, the LS427 uses a conventional wet-sump oiling system with an F-body aluminum oil pan and wet-sump pump, eliminating the need for an external oil tank and plumbing required by the LS7's dry-sump system. This change makes the engine easier to install in a wider range of vehicles. The LS427 is equipped with a unique hydraulic roller camshaft featuring .591 in intake and .590 in exhaust lift and longer duration (227° intake / 242° exhaust), resulting in a power increase to and of torque. Other changes include fifth-generation Camaro Z/28 exhaust manifolds and a 14 in manual transmission flywheel from the Z/28 platform, replacing the LS7’s stock components. It retains key LS7 features such as forged steel crankshaft, titanium connecting rods, CNC-ported aluminum cylinder heads with 70cc combustion chambers, and a 7000 rpm redline. The engine is supplied fully assembled with intake manifold, fuel rails, injectors, throttle body, ignition coil packs, balancer, and water pump. It requires a specific LS427/570 engine controller (P/N 19420000) calibrated for this engine. The LS427 was discontinued in January 2022 along with the LS7. 4.06 in. bore blocks (2007–2017) This family was designed as a replacement for the LS2 but enlarged to better accommodate variable valve timing and Active Fuel Management while still generating decent performance. This family of engines has mainly seen duty in performance cars and high-end SUVs. 6.2 L L92 / L9H / L94 The L92, also known as the Vortec 6200, displaces , and debuted in the 2007 Cadillac Escalade. It is an all-aluminum design which, while still a pushrod engine, has variable valve timing. The system adjusts both intake and exhaust timing between two settings. This engine produces and in the GMC Yukon Denali/XL Denali, GMC Sierra Denali, Hummer H2, and briefly in the Chevrolet Tahoe LTZ (MY 2008.5 – MY 2009) and rated at and . Starting in 2009, it was also available in the Chevrolet Silverado and GMC Sierra, as the L9H, with power ratings of and . Engines built prior to April 1, 2006, contained AFM hardware; however, the mode was not enabled in the PCM, and thus the system was not functional. Engines built after this date also lacked any AFM hardware, and instead used a valley cover plate similar to the L20, until the debut of the L94 variants mentioned below. The 2009 L92 was modified with flex-fuel capability, becoming the L9H, but still had no AFM hardware. In 2010, the L9H was further modified with Active Fuel Management, becoming the L94 (in the Cadillac Escalade and GMC Yukon Denali). Applications: • 2007–2013 Cadillac Escalade (L92 for MY 2007–2008, L9H for MY 2009, L94 for MY 2010–2013) • 2008–2009 Chevrolet Tahoe LTZ (as RPO code L92) • 2007–2013 GMC Yukon Denali / Yukon XL Denali • 2007–2013 GMC Sierra 1500 Denali • 2008–2009 Hummer H2 • 2009–2013 Chevrolet Silverado 1500 (as RPO code L9H) • 2009–2013 GMC Sierra 1500 (as RPO code L9H) LS3 : LS3 can also refer to a Chevrolet Big-Block engine of the 1970s. The LS3 was introduced as the Corvette's new base engine for the 2008 model year. It produces at 5900 rpm and at 4600 rpm without the optional Corvette exhaust and is SAE certified. The block is an updated version of the LS2 casting featuring a larger bore of creating a displacement of . It also features higher flowing cylinder heads sourced from the L92, a more aggressive camshaft with lift, a 10.7:1 compression ratio, a revised valvetrain with offset intake rocker arms, a high-flow intake manifold, and /hour fuel injectors from the LS7 engine. The L76/L92/LS3 cylinder heads use intake valves, and exhaust valves. Improved manufacturing efficiency makes these heads cheaper to produce than the outgoing LS6 heads, significantly undercutting the price of aftermarket heads. The large valves, however, limit maximum rpm – 6000 in the L76 (with AFM), and 6600 in the LS3 (with hollow stem valves). In addition to the above, a dual-mode exhaust package with a bypass on acceleration was available on C6 Corvettes. The dual-mode exhaust uses vacuum-actuated outlet valves, which control engine noise during low-load operation, but open for maximum performance during high-load operation. The system is similar to the C6 Z06, but uses a diameter exhaust compared to the Z06's . Power is boosted to and with this option. A similar system was optional on later-model fifth-generation Chevrolet Camaros and standard on the 2016–2017 Chevrolet SS, but no horsepower or torque increases were advertised on those vehicles. LS3 engines found in manual transmission-equipped C6 Corvette Grand Sport models also received a dry sump oiling system similar to the one fitted to LS7-equipped Corvettes. From April 2008, Australian performance car manufacturer HSV adopted the LS3 as its standard V8 throughout the range, replacing the 6.0-liter LS2. The LS3 received modifications for its application to HSV E Series models, producing . The LS3 engine in the E Series II GTS (released September 2009) was upgraded to produce . All HSV MY12.5 excluding the base Maloo and Clubsport variants have been upgraded to produce . From September 2015, Holden introduced the LS3 in all V8 models of the VF II Commodore and WN II Caprice-V, replacing the 6.0L L77. Applications: • 2008–2013 Chevrolet Corvette • 2010–2015 Chevrolet Camaro SS (manual only) • 2008–2017 Holden vehicles including: • 2008–2013 HSV E Series • 2009 Pontiac G8 GXP • 2014–2017 Chevrolet SS • 2009–2017 Vauxhall VXR8 • 2015–2017 Holden WN II Caprice • 2015–2017 Holden VF II Commodore • 2012 AC 378 GT Zagato • 2015 SIN R1 450 • 2016 Arrinera Hussarya • 2019 Bolwell Nagari 500 L99 The L99 is derived from the LS3 with reduced output but adds Active Fuel Management (formerly called Displacement on Demand) and variable valve timing, which allows it to run on only four cylinders during light load conditions. Applications: • 2010–2015 Chevrolet Camaro SS (automatic transmission) LS9 The Gen IV LS9 is a supercharged engine, based on the LS3; the LS7 block was not used because of the higher cylinder pressures created by the supercharger requiring the thicker cylinder walls of the LS3. It has a bore and stroke of . It is equipped with an Eaton four-lobe Roots type supercharger and has a compression ratio of 9.1:1. Power output is rated at 6500 rpm and at 3800 rpm of torque. Note: GM previously used the LS9 RPO code on 1969 and later Chevrolet trucks (both 2WD and 4WD) including Blazers, Jimmys, and Suburbans, as well as car carriers. The original LS9 was a V8, developing and of torque. In 2017, Holden Special Vehicles used a modified version of the LS9 in their GTSR W1, the last-ever Holden Commodore based vehicle produced in Australia. Applications: • 2009–2013 Chevrolet Corvette ZR1 • 2009 Savage Rivale Roadyacht GTS • 2010 HTT Pléthore LC 750 • 2015 Equus Bass 770 • 2015–present SIN R1 650 • 2016 Icona Vulcano Titanium • 2016 VLF Destino • 2017 HSV GTSR W1 LSA The supercharged 6.2L LSA is similar to the LS9 and debuted in the 2009 CTS-V. The LSA has been SAE certified at at 6100 rpm and at 3800 rpm. GM labeled it "the most powerful ever offered in Cadillac's nearly 106-year history." The LSA features a smaller supercharger rather than the variant of the LS9. Other differences include a slightly lower 9.0:1 compression ratio, single-unit heat exchanger, and cast pistons. A and version of the LSA engine is used in the 2012 Camaro ZL1. On May 15, 2013, Holden Special Vehicles announced that this version of the LSA engine would also be used in the GEN-F GTS. Applications: • 2009–2015 Cadillac CTS-V • 2012–2015 Chevrolet Camaro ZL1 • 2014–2017 HSV GTS GEN-F • 2013–2017 Vauxhall VXR8 GTS, GTS-R ==Generation V (2013–present)==

| - V6 only | | }} | | (L8T only) }} | 10.0:1 | 11.0:1 | 11.5:1 }} }} In 2007, WardsAuto.com reported that the LS3 (used in the 2008 Chevrolet Corvette) and Vortec 6000 LFA (used in the 2008 Chevrolet Tahoe Hybrid) engines would be the final two designs in the Generation IV small-block engine family, and the future designs would be part of the Generation V engine family. An experimental engine was built based on the L92 engine from the Cadillac Escalade, GMC Yukon Denali, and Hummer H2, and reported to generate on gasoline via direct fuel injection, increased compression ratio to 11.5:1, and a modified engine controller. The first Gen V LT engine was the LT1, announced in 2012 as the initial powerplant for the redesigned Corvette C7, succeeding the LS engine family. The new logo formally adopts the Small Block name for the engines. The fifth generation of the iconic GM small block engine family features the same cam-in-block architecture and bore centers (the distance between the centers of each cylinder) that were born with the original small block in 1954. Structurally, the Gen-V small-block is similar to the Gen III/IV engines, including a deep-skirt cylinder block. Refinements and new or revised components are used throughout, including a revised cooling system and all-new cylinder heads. Because the positions of the intake and exhaust valves are flipped from where they would be in an LS engine, as well as the need for an addition to the camshaft to drive the high-pressure fuel pump for the direct fuel injection, few parts are interchangeable with the Gen III/IV engines. All Gen V engines use aluminum blocks with aluminum cylinder heads, and include direct injection, piston cooling jets, active fuel management, variable displacement oil pump, and continuously variable valve timing. (The L8T is an exception; see below for details.) However, they all retain their ancestors' two-valve pushrod valvetrain and 4.4 inch bore spacing. 4.065 in. bore blocks (2014–present) This family of blocks was the first of the Generation V small block with the LT1 being the progenitor of this family and generation. This family of blocks has seen a wide range of applications from performance vehicles to truck usage. 6.2 L LT1 LT1 The LT1 engine debuted in the 2014 Chevrolet Corvette Stingray and is the first Generation V small block engine. Like its LS3 predecessor, it gets its displacement from a bore and stroke of with a compression ratio of 11.5 to 1. Applications: LT2 The LT2 engine debuted in the 2020 Corvette Stingray as the successor to the LT1. It was designed specifically with mid-engine placement and dry-sump lubrication in mind. It was replaced for 2027 by the LS6. Applications: L86/L87 The EcoTec3 is a Generation V small-block V8 truck engine (VIN code "J"). The L86 is an LT1 engine modified for truck use with a compression ratio of 11.5 to 1. In 2019, GM introduced the L87 as the successor to the L86. Power and torque remain the same, but whereas the L86's "Active Fuel Management" alternates between V4 and V8 modes, the L87's "Dynamic Fuel Management" can alternate between any of 17 different firing orders which vary both how many and which cylinders are actually firing based on demand calculated every 125 milliseconds. Applications: LT4 The LT4 engine builds on the design strengths of the previous LS9 supercharged engine used in the sixth-generation Corvette ZR1 and leverages the technologies introduced on the seventh-generation Corvette Stingray, including direct injection, cylinder deactivation, and continuously variable valve timing, to take Corvette performance to an all-new level. The LT4 engine is based on the same Gen 5 small block foundation as the Corvette Stingray's LT1 6.2L naturally aspirated engine, incorporating several unique features designed to support its higher output and the greater cylinder pressures created by forced induction, including: Rotocast A356T6 aluminum cylinder heads that are stronger and handle heat better than conventional aluminum heads, lightweight titanium intake valves, forged powder metal steel connecting rods, 10.0:1 compression ratio, enhanced performance and efficiency enabled by direct injection, forged aluminum pistons with unique, stronger structure to ensure strength under high cylinder pressures, stainless steel exhaust manifolds for structure at higher temperatures, aluminum balancer for reduced mass, and standard dry-sump oiling system with a dual-pressure-control oil pump. The engine uses a Eaton TVS Supercharger. Although smaller than the previous supercharger used on the sixth-generation ZR1, it spins to 5000 rpm faster thus generating boost quicker while making only slightly less total boost than the LS9 engine. The Escalade-V variant uses a Eaton TVS supercharger. This engine is also used by Scuderia Cameron Glickenhaus for their SCG 004S. The limited production IsoRivolta GTZ, which is based on the C7 Z06, also uses the LT4 engine. Applications: LT5 The LT5 engine debuted in the seventh-generation Corvette ZR1 at the 2017 Dubai Motor Show. It draws its name from the 5.7 L LT5 from the C4, manufactured from 1989–1993. The original LT5 is rarely known as a Chevy small block V8, as it was designed by Lotus, built by Mercury Marine, and implements a DOHC 32-valve multi-port injection system, instead of the 16-valve push-rod design. The new (and unrelated) LT5, however, has increased its displacement from 5.7 to 6.2L (350 to 376 cu in), retains the Gen V OHV valvetrain, and is topped with a Eaton TVS supercharger and an improved intercooler. It simultaneously couples the standard direct injection system found on Gen 5 engines with port fuel injection, specifically to satisfy upper-RPM fuel demands. Power output is at 6400 rpm and of torque at 3600 rpm. Applications: 6.6 L L8T The L8T is the first iron block member of the Gen V family, and is the successor to the 6.0L Gen IV L96. It shares its bore with other 6.2L V8s such as the L86, but with a longer stroke of to displace . It is rated for at 5,200 rpm and of torque at 4,000 rpm. The compression ratio is 10.8:1. The longer stroke yields little additional peak torque output compared to the L86, but only requires 87 Octane. The stroke is also shorter than the LS7's , to optimize rod ratio for reliability. Rather than allow a "high-strung" small-block to fail the heavy-duty truck market, the iron block, lack of both stop-start and cylinder deactivation, longer stroke and rod ratio, lower compression, lesser 87 Octane requirement, greater displacement, forged connecting rods, and forged crankshaft with central counterweights all suggest that the L8T was designed specifically to assuage the heavy-duty truck market's concerns. Applications: L8P The L8P is a Chevrolet Performance Crate engine released in 2025 that takes the base L8T and adds high performance heads, camshaft, and pistons. The L8P has the same 6.6L (400 cu. in.) displacement, but is rated at 523 hp at 5800 rpm and 543 lb-ft of torque at 4600 rpm, on premium pump gasoline. 3.78 in. bore blocks (2014–present) Unlike the previous Generation III/IV bore block families, there is no displacement variant (having been 'replaced' by GM's 5th Generation LT V8-based V6, the LV3). 5.3 L L83 Dubbed EcoTec3, the is a Generation V small block V8 truck engine (VIN code "C"). Like its Vortec 5300 Generation IV predecessor, it gets its displacement from a bore and stroke of with a compression ratio of 11.0:1. Applications: L8B The L8B is an eAssist mild hybrid version of the L83 featuring a 0.45-kWh lithium ion battery pack. This setup can improve fuel efficiency by about 13%. This adds about to the total weight of the truck but provides an additional and . Applications: L82/L84 The L82 is one of two 5.3L V8s available in the fourth-generation Chevrolet Silverado and fifth-generation GMC Sierra. The L82 uses Active Fuel Management instead of the L84's Dynamic Fuel Management system and is only available on lower-trim trucks. The L84 is one of two 5.3L V8s available in the 4th generation Chevrolet Silverado and GMC Sierra. The L84 is distinguished from the L82 by the presence of the Dynamic Fuel Management System and is either available or standard on mid-to-high-level trims. The L84 is also the base engine on the 2021–present Chevrolet Tahoe, GMC Yukon, Chevrolet Suburban, and GMC Yukon XL. Applications: 3.921 in. bore blocks (2014–present) These V6 engines are based on the V8 version of the Gen V family, but with two fewer cylinders – a design lineage that dates back to the previous 4.3L V6, which was itself a Gen I small block with a pair of cylinders removed. Of special note, there were no V6 engines based on Generation II, III, or IV small-block V8s. 4.3 L Dubbed EcoTec3, the is a Generation V small block V6 truck engine. It gets its displacement from bore and stroke of with a compression ratio of 11.0 to 1. Firing order is 1-6-5-4-3-2. This engine replaces the unrelated 4.3L V6 whose lineage dates back to 1978. LV3 Applications: LV1 The engine is essentially the same as the LV3, but without Active Fuel Management technology. The LV1 made its debut in the 2018 model year GM full-size vans—the 2018 Chevrolet Express and 2018 GMC Savana—as the successor to the Gen IV 4.8L L20. Applications: ==Generation VI==

General Motors announced in January 2023 that plans for a sixth generation of small-block were in place, with the company investing $854 million into its various manufacturing plants. The timeline for the release of the new generation is not yet public. However, the first appearance of the new engine is expected in the upcoming fifth generation Chevrolet Silverado in 2027. GM has announced the 2027 Corvette will receive the first generation VI engine, replacing the generation V LT2. General Motors has announced that the sixth generation V8 small-block will be produced in Flint, MI and Tonawanda, NY. The engines will come in two displacements of roughly 5.7 liters and 6.6 liters. 4.065 in. bore blocks (2027–present) LS6 The LS6 engine will debut in the 2027 Corvette Stingray. The LS6 uses combined port and direct injection and has a compression ratio of 13.0:1 and max engine speed of 6,600 rpm. The bore stays the same as the outgoing LT2 at , but the stroke is increased to , increasing displacement to . Applications: == Engine table ==

The eighth character in the VIN or the RPO code from the glove box sticker can be used to identify which type of LS engine a vehicle has. If you are looking at donor vehicles, be aware that the 8th character is usually not the same between different platforms (i.e., car vs truck vs suv, Camaro vs Silverado vs Escalade). ==Known issues==

In the early production run of the LS-series engine, some engines encountered 'piston slap' during the first few minutes after a cold engine start; this sound is caused by the pistons rocking slightly in the cylinder until they reach operating temperature/size. "Piston slap" sometimes sounds more like a knock or the sound of a diesel engine running. It is typically only present when the engine is cold and disappears as the engine reaches operating temperature. Another common problem with the 2001–2006 5.3L engines was cracking cylinder heads. This is commonly called the "Castech Head" failure. GM issued a Technical Service Bulletin on this failure to help service technicians identify the problem. The head casting number (which can be viewed from the passenger side of the vehicle just in front of the valve cover) was 706. Some heads with this casting number would fail (but not all of them) as GM had different suppliers for the same head. The failure was due to undetected porosity around the oil drains in the head. Yet another common problem with the 2005–2016 fourth generation V8 LS engines was a failure of the specialized lifters in engines equipped with the AFM system. While in AFM operation, the lifters would sometimes fail to come out of AFM mode and cause the engine to go into 'limp home' mode. In this mode damage could occur to the pistons, camshaft, or the lifters themselves. The resulting solution was a package of components that would replace the lifters, lifter guides, camshaft, Valve Lifter Oil Manifold (VLOM) plate. Cylinder heads were required to be removed from the engine in order to replace all the components. The engine computer also required reprogramming to permanently Disable AFM. ==Build-your-own program==

In 2011, Chevrolet Performance began to offer the build your own engine program for LS7 (part number 19259944) or LS9 (part number 19259945) crate engines. It also provides customers the experience of visiting GM's unique Performance Build Center in Wixom, Michigan, where they will join a specially trained engine builder to assist in the start-to-finish assembly of the engine they purchased – from installing the crankshaft in the cylinder block to topping off the engine with its intake system. In the case of the LS9, it also means installing the supercharger assembly. Upon completion, a personalized nameplate is added to the engine. The build-your-own engine program associated with the V8 engines, available for buyers of Chevrolet Corvette, Cadillac XLR, and certain top-spec Chevrolet Camaro models, was temporarily halted after the closure of GM Performance Build Center in Wixom, Michigan. The program's venue was reported to be relocated to the Corvette assembly plant in Bowling Green, Kentucky. == Aftermarket ==

; LS5.5R The LS5.5R engine was designed and built by GM for the Corvette C6.R in the GT2 (later LM GTE) class, at the Wixom Performance Build Center, where the production Corvette engines were made. GT2 rules stated that displacement for naturally aspirated engines could not exceed . This forced Corvette Racing and GM to reduce the size of their new engine, which they did by decreasing the crankshaft stroke to from in the previous Katech LS7.R based engine. At 5,800 rpm, the LS5.5R produces 485 horsepower and at 4,500 rpm produces of torque. ; LSX LSx is also used to denote any LS engine. At the 2006 SEMA show, GM Performance Parts introduced the LSX engine, an all-new cast-iron racing block based on the LS7 engine. It was designed with help from drag racing legend Warren Johnson. It offers displacements ranging from with a bore and stroke of and is capable of withstanding . This block incorporates two extra rows of head-bolt holes per bank for increased clamping capacity. The six bolt steel main caps are the same ones used on the LS7 engine. The engine debuted at the auto show in a customized 1969 Camaro owned by Reggie Jackson. The LSX was available starting the second quarter of 2007, set to be available in authorized dealerships and retailers on March 31, 2007. The Hennessey Venom GT also uses the LSX engine based on LS7. Chevrolet Performance LSX Bowtie block includes LSX specific six-bolts-per-cylinder head bolt pattern, billet-steel six-bolt dowel-located main bearing caps, extra-thick deck for maximum clamping force, extra-thick cylinder walls allow increased bore capacity (maximum bore still allows minimum wall thickness), true priority main oiling system, main web bay-to-bay breathing holes reduce crank windage, orange powder coat finish, machined bore at is ready for final boring/honing. A version engineered by Ilmor is used in NASCAR for the Craftsman Truck Series and the ARCA Racing Series as an option engine. Most teams in both series (known as "NT1" in the Truck Series and the "ARCA 396" in ARCA) have switched to the engine because of cost savings, as engines must last 1,500 miles and rebuilds are about one-thirds the cost of a new engine. ; LSX376 Chevrolet Performance LSX376 crate engines are updated versions of LSX crate engine family designed to support up to . All models use the Chevrolet Performance LSX Bowtie block. LSX376-B15 (part number 19299306) includes forged steel crankshaft, forged powdered metal I-beam rods (both the crankshaft and rods from the LSA engine), forged aluminum pistons (9.0:1 compression), and high-flow rectangular-port six-bolt LSX-LS3 heads for supercharged and turbocharged combinations producing up to of boost and up to about . LSX376-B8 (part number 19171049) is a more economical version that is capable of approximately , for an engine producing approximately . It is designed for production-style supercharger and turbo systems used without enhancements or modifications. ; LSX454 and LSX454R Chevrolet Performance created the 454 big-block Chevy race engine in 1970 and continued production of the crate engine through 2001. The addition of EFI and picking up the Vortec 7400 name took place in 1996 which was replaced with the Vortec 8100 platform once the 7400 was retired. Chevrolet Performance released the 454 again in 2011 as a small-block crate engine dubbed the LSX454R officially rated at 776 horsepower at 7,000 rpm and 649 lb-ft of torque at 5,100 rpm. The LSX454R was discontinued in July 2018 and was recorded as one of the more powerful LS crate engines to be assembled from Chevy Performance. ; Noonan Race Engineering Noonan Race Engineering developed two billet aluminum blocks based on the LS engine. Bore sizes are up to and stroke up to are available, making a displacement possible. The billet construction provides added block integrity suited to high horsepower applications. The block design incorporates turbocharger pressure feed lines in the front of the valley and oil dump ports in the side of the block to return oil to the sump. In addition to the solid block, a waterjacketed version was designed to provide better cooling options for street or endurance purposes. Noonan also developed intake manifolds for the LS, specifically for turbocharging or twin turbo charging or supercharging. ==See also==