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|GM small-block engine|
|GM small-block engine|
The GM small-block engine family is an engine design intended as the only V-8 engine used in General Motors' line of rear-wheel-drive cars and trucks. The GM small-block series was a "clean sheet" design with little in common in terms of shared parts with the classic Chevrolet small block V8. The basic layout owes a good deal to the essential concept of Ed Cole's original small-block design of 1954-55, though the small-block engine also uses design cues from Buick, Oldsmobile, and Pontiac engines. Some small-block engines are all-aluminum, especially the performance oriented engines, while others are cast iron, and all small-block engines have six main bearingbearing caps.
The small-block engine has been the sole powerplant of the Chevrolet Corvette from 1997-2013 and has seen use in a wide variety of other General Motors vehicles, ranging from sport coupes to full size trucks. Due to the engine's relatively compact external dimensions compared to its displacement and power output, the engine family is also a popular choice for import cars, kit cars, hot rods, buggies, and even light aircraft.
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|Also called||GM LT engine|
|Cylinder block alloy|
|Cylinder head alloy|
|Oil system||Wet sump|
A significant improvement over the original Generation I V8 is the Generation II LT's "reverse cooling" system, allowing coolant to start at the heads and flow down through the block. This keeps the heads cooler, affording greater power through a higher compression ratio and greater spark advance at the same time it maintains higher and more consistent cylinder temperatures.
Some parts from the Generation II are interchangeable with the Generation I one-piece rear main seal engine. The interchangeable parts include the rotating assembly (crank shaft, pistons, connecting rods, and flywheel/flexplate) and valvetrain assembly (not including timing set, which includes a gear to drive the water pump). The LT uses a new engine block, cylinder head, timing cover, water pump, intake manifold and accessory brackets. The harmonic dampener also does not interchange; it is a unique dampener/pulley assembly. Engine mounts and bell housing bolt pattern remain the same, permitting a newer engine to be readily swapped into an older vehicle.
In 1992, GM created a new-generation small-block engine called the "LT1 350", not to be confused with the high-output Generation I LT-1 of the 1970s. It displaced 5.7 L (350 cu in), and was a 2-valve pushrod design. The LT1 used a reverse-flow cooling system which cooled the cylinder heads first, maintaining lower cylinder temperatures and allowing the engine to run at a higher compression than its immediate predecessors.
This engine was used in:
There were a few different versions of the LT1. All feature a cast iron block, with aluminum heads in the Y and F bodies, and cast iron heads in the B and D bodies. Corvette blocks had four-bolt main caps, while most other blocks were two-bolt main caps.
The 92–93 LT1s used speed density fuel management, batch-fire fuel injection and a dedicated Engine Control Module (ECM). In 94 the LT1 switched to a mass airflow sensor and sequential port injection. A new, more capable computer controlled the transmission as well as the engine and got a new name: Powertrain Control Module (PCM). Where the ECM held its calibration information in a replaceable PROM chip, the 94-95 OBD1 PCMs are reprogrammable through the diagnostic port.
The early Optispark distributor had durability problems and a revised version was introduced with vacuum vents to remove moisture on the 1994 B-Bodies and in 1995 on the Y and F-Bodies; the vacuum vents can be added onto earlier distributors. 1996 saw major revisions for OBD-II: a second catalytic converter on the F-body cars and rear oxygen sensors to monitor catalyst efficiency. Some OBD-II features had been added to the Corvette starting in 1994 for testing purposes. The 1997 model year Camaro and Firebird were the last year for this engine in a GM production car before it was replaced by the LS1, which was already in the Corvette for 1997.
The 1992 LT1 in the Y-body was factory rated at 300 hp (220 kW) and 330 lb·ft (447 N·m). 96 LT1 Y-bodies were rated at 300 hp (220 kW) and 340 lb·ft (461 N·m). The 93–95 F-bodies were rated at 275 horsepower (205 kW) and 325 lb·ft (441 N·m), while the 96–97 cars were rated at 285 horsepower (213 kW) and 335 lb·ft (454 N·m). The 96–97 WS6 and SS F-bodies were rated at 305 hp (227 kW). The 94–96 B and D-body version was rated at 260 horsepower (190 kW) and 330 lb·ft (447 N·m).
The LT4 was a special high-performance version of the new-generation LT1. With the addition of a slightly more aggressive camshaft profile, 1.6:1 roller aluminum rocker arms, high-flow cylinder (painted red) with extra material above the port available to allow port matching to the raised port LT4 cylinder heads, it was rated at 330 horsepower (250 kW) and 340 lb·ft (461 N·m). It was introduced in the 1996 model year, for the last year of the C4 Corvette, and came standard on all manual transmission (ZF 6-speed equipped) C4 Corvettes. The engine was passed down to special versions of the Camaro and Firebird the next model year.
The LT4 was available on the following vehicles:
All 135 production engines for the Firehawks and Camaro SS were completely disassembled, balanced, blueprinted and honed with stress plates. One in 5 engines was tested on a Superflow engine dyno and every car was tested on a chassis dyno in addition to performing a short 6-mile (10 km) road test.
A 260 in3 (4.3 L) was based on a 305 in3 with updated block architecture to be Generation II and a reduced 3 inches (76 mm) stroke. It was designated the L99, and was introduced in 1994 for the Chevrolet Caprice. It was externally identical to the LT1, but the bore was decreased to 3.736 inches (94.9 mm) and the stroke to 3 inches (76 mm) giving it a displacement of 263 in3. The pistons used in the L99 were the same as the ones used in the Vortec 5000, but 5.94 inches (151 mm) connecting rods were used to compensate for the shorter stroke. This was the base engine used on all 1994-1996 Chevrolet Caprice Sedans, including the Police Package vehicles.
Like the LT1, it features sequential fuel injection, reverse-flow cooling, and an optical ignition pickup. Output is 200 hp (150 kW) and 245 lb·ft (332 N·m). Due to its smaller displacement, it provides better fuel economy than the 5.7 L LT1, but at reduced horsepower & torque levels.
For model year 1990, Chevrolet released the Corvette ZR-1 with the radical overhead cam LT5 engine, which shared only the 4.4 inch bore spacing with any previous LT engine. The LT5 was engineered by Lotus Engineering in the UK headed by design manager David Whitehead, the engine was produced by Mercury Marine at Stillwater OK headed by Project Engineer Terry D. Stinson. It was an all-aluminum 5.7 L (349 cu in) small-block V8, but was thoroughly different from any of the other Chevrolet 350 engines. The bore and stroke were both different at 3.9 by 3.66 in (99 by 93 mm) instead of the usual 4 by 3.48 in (102 by 88 mm) and it featured Lotus-designed 32-valve DOHC heads rather than the usual Chevrolet 16-Valve OHV Heads. It was hand built by specialty engine builder, Mercury Marine in Stillwater, OK. This engine produced 375 horsepower (280 kW) and 370 lb·ft (502 N·m) for the 1990-1992 Corvette ZR-1 and jumped to 405 horsepower (302 kW) and 385 lb·ft (522 N·m) from 1993 until its final year in 1995, thanks to cam timing changes and improvements to the engine porting. 1993 also added 4-bolt main bearing caps and an exhaust gas recirculation system. The engine was used only in Corvettes. The LT5 was very expensive, and after six years of production, GM canceled the ZR-1 option. A total of 6939 were produced. The LT5 however wasn't an evolutionary dead end. Despite being discontinued, a new class of premium V8s for Cadillac and eventually Oldsmobile, the dual overhead cam V8 Northstar and its derivatives, drew heavily from the LT5's design and lessons learned from its production.
The LT5 does not have reverse cooling.
The LT5 was available on the following vehicles:
|Cylinder block alloy|
|Cylinder head alloy||Aluminum|
|Fuel system||Sequential multi-port fuel injection|
|Oil system||Wet sump|
The Generation III V-8 engines replaced the Gen II-LT family in 1997 and Gen I completely by 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/GMC Extended Cab Standard Box Z71 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 and with the iron LS engines far exceeding the capabilities of the previous two generations. The LS engine also used coil-near-plug 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 64-90 Oldsmobile V-8 ), 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 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).
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.
The Generation III 5.7 L shares little other than similar displacement, external dimensions, and rod bearings, with its predecessor (LT1). It is an all-aluminum 5,665 cc (5.665 L; 345.7 cu in) pushrod engine with a bore of 3.898 in (99.0 mm) and a stroke of 3.62 in (92 mm).
When introduced in the 1997 Corvette the LS1 was rated at 345 hp (257 kW) at 5,600 rpm and 350 lbf·ft (470 N·m) at 4,400 rpm. After improvements to the intake and exhaust manifolds in 2001 the rating improved to 350 hp (260 kW) and 365 lbf·ft (495 N·m). The LS1 was used in the Corvette from 97-04. It was also used in 98-02 GM F-Body (Camaro & Trans Am) cars with a rating of 305–325+ HP, 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 bhp (285 kW) in the HSV's YII series, and a Callaway modified version named "C4B" was fitted to HSV GTS models producing 402 bhp (300 kW).
The LS6 is a higher-output version of GM's LS1 engine and retains the same capacity. The initial 2001 LS6 produced 385 bhp (287 kW) and 385 lbf·ft (522 N·m), but the engine was modified for 2002 through 2004 to produce 405 bhp (302 kW) and 400 lbf·ft (540 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 400 bhp (300 kW) 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, a camshaft with higher lift and more duration, a higher compression ratio of 10.5:1, sodium filled 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. Applications:
The 4.8 L and the 5.3 L are smaller truck versions of the LS1 and were designed to replace the 305 and the 350 in trucks. Both the 4.8 L and the 5.3 L share the same engine block, heads (upper end) and as they share architecture, parts interchange freely between these engines and other variants in the LS family.
The Vortec 4800 LR4 (VIN code "V") is a Generation III small block V8 truck engine. Displacement is 4.8 L (293 cu in) with a 96.01 mm (3.78 inch) bore and 83 mm (3.27 inch) stroke. It is the smallest of the Generation III Vortec truck engines and was the replacement for the 5.0 L 5000 L30. The LR4 engines from 1999-2000 produced 255 hp (190 kW) while the 2001 and above models made 270–285 hp (201–213 kW) and all have a torque rating between 285–295 lb·ft (386–400 N·m), depending on the model year and application. The 2005-2006 models made 285 hp (213 kW) and 295 lb·ft (400 N·m), LR4s are manufactured at St. Catharines, Ontario and Romulus, Michigan. It uses flat top pistons.
The Vortec 5300, or LM7/L59/LM4, is a V8 truck engine. It is a longer-stroked (by 9 mm (0.35 in)) version of the Vortec 4800 and replaced the L31. L59 denoted a flexible fuel version of the standard fuel LM7 engine. Displacement is 5.3 L (5,328 cc (325.1 cu in)) from 3.78-inch (96 mm) bore and 3.622-inch (92.0 mm) stroke. Vortec 5300s are built in St. Catharines, Ontario and Romulus, Michigan. Another engine variant, the L33, shares the same displacement, but has an aluminum block with cast in cylinder liners, much like the LS1. This allowed a 100 lb (45 kg) weight savings over the standard LM7 model. Other differences were a higher lift cam shaft (0.482 in (12.2 mm) v. 0.456 in (11.6 mm) on both intake & exhaust), higher compression ratio (9.9:1 v. 9.49:1), and cylinder heads originally designed for the LS6. These differences bumped output: GM rated the engine at 315 hp (235 kW) and 338 lbf·ft (458 N·m).
The Vortec 5300 LM7 (VIN code 8th digit "T") was introduced in 1999, and can be considered the "garden variety" version of the Generation III 5.3 liter V8's. The 1999 LM7 engine produced 270 hp (201 kW) and 315 lb·ft (427 N·m), 2000-2003 engines made 285 hp (213 kW) and 325 lb·ft (441 N·m). The 2004-2007 engines made 295 hp (220 kW) and 335 lb·ft (454 N·m), it has a cast iron block and aluminum heads.
The Vortec 5300 L59 (VIN code "Z") is a flexible fuel version of the LM7. The 2002-2003 made 285 hp (213 kW) and 320 lb·ft (434 N·m), while the 2004-2007 L59s made 295 hp (220 kW) and 335 lb·ft (454 N·m).
The Vortec 5300 LM4 (VIN code "P") is an aluminum block version of the LM7, and had a short production life. The LM4s made 290 hp (216 kW) and 325 lb·ft (441 N·m), It should not be confused with the L33 described below.
The Vortec 5300 L33 (VIN code "B") is an aluminum block version of the LM7, and was referred to as the Vortec 5300 HO in marketing materials. How ever it should be noted that the L33 uses a flat top piston from the 4.8L instead of the standard dish piston found in the LM7. It also uses 799 cylinder heads, which are identical to the 243 casting found on the LS6 and LS2 with the exception to the Corvette spec valve springs, and hollow stem exhaust valves on the 2002-2004 LS6. This combination increased the compression from 9.5:1 to 10.0:1. Also the L33 had a specific camshaft not shared with any other engine, with lobe lift of 7.2 mm, 193 degrees of intake and exhaust duration, and a 116 degree lobe separation angle. As a result power increased by 15 hp (11 kW), to 310 hp (230 kW) and 335 lb·ft (441 N·m). It was only available on extended cab 4WD pickup trucks. Only 25% of trucks made in 2005 had the L33 engine.
The 6.0 L is a larger truck version of the LS1, with the exception that the blocks were cast of iron, and was designed to bridge the gap between the new small blocks and big blocks in truck applications. There were two version of this engine: the LQ4 and the LQ9, the latter being more performance oriented. Although the block of the 6.0L looks similar to the LS1, they are iron instead of aluminum.
The Vortec 6000 is a V8 truck engine. Displacement is 6.00 L (366 cu in) from 101.6 mm (4.00) bore and 92 mm (3.622") stroke. It is an iron/aluminum (1999 & 2000 model year engines had cast iron heads) design and produces 300 horsepower (220 kW) to 345 horsepower (257 kW) and 360 lbf·ft (490 N·m) to 380 lbf·ft (520 N·m).
The Vortec 6000 LQ4, is a V8 truck engine. Displacement is 5.97 L (364 cu in) from a 4.0-inch (101.6 mm) bore and 3.622-inch (92.0 mm) stroke . It is an iron/aluminum (1999 & 2000 model year engines had cast iron heads) design and produces 300 hp (224 kW) to 325 hp and 360 lb·ft (488 N·m) to 370 lb·ft (502 N·m). LQ4s are built in Romulus, Michigan and Silao, Mexico.2013 model year produces 360 hp
LQ4 (VIN U) Applications:
The Vortec HO 6000 or VortecMAX is a special high-output version of the Vortec 6000 V8 truck engine originally designed for Cadillac. This engine was introduced in other truck lines as VortecMAX for 2006. It features high-compression (10:1) flat-top pistons for an extra 10 hp (7 kW) and 10 lb·ft (14 N·m), bringing output to 345 hp (257 kW) and 380 lb·ft (515 N·m). LQ9s are built only in Romulus, Michigan.
LQ9 (VIN N) Applications:
|Cylinder block alloy|
|Cylinder head alloy||Aluminum|
|Fuel system||Sequential multi-port fuel injection|
|Oil system||Wet sump|
In 2005, the Generation III was superseded by the Generation IV. This category of engines has provisions for high-displacement ranges up to 7,011 cc (7.011 L; 427.8 cu in) and power output to 638 bhp (476 kW). Based on the Generation III design, 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 3-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.
This family of blocks were 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.
The Generation IV 6000 is a V8 engine that displaces 5,967 cc (364.1 cu in) from 101.6 mm (4.000 in) bore and 92 mm (3.622 in) stroke. It features either a cast iron or aluminum engine with cast aluminum heads. Certain versions feature variable cam phasing, Active Fuel Management, and Flex-fuel capability.
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 400 bhp (300 kW) at 6000 rpm and 400 lb·ft (542 N·m) at 4400 rpm from a slightly larger displacement of 5,967 cc (5.967 L; 364.1 cu in). 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 18 cubic inches. 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 412 bhp (307 kW) and 412 lbft . The LS2 in the Chevrolet Trailblazer SS and the Saab 9-7X Aero are rated at 395 bhp (295 kW) (2006–2007) or 390 bhp (290 kW) (2008–2009) and 400 lb·ft (542 N·m) 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 NASCAR V8 cylinder block cast in Compacted Graphite Iron by Grainger & Worrall won the UK's Casting of the Year Award 2010.
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 348 bhp (260 kW) at 5600 rpm and 376 lb·ft (510 N·m) at 4400 rpm for the Holden variant, and 361 bhp (269 kW) and 385 lb·ft (522 N·m) 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 367 hp (274 kW) at 5400 rpm and 375 lb·ft (508 N·m) at 4400 rpm. Production of the Vortec 6000 started in late 2006, and is only available with the new body style Silverado and Sierra. The final year for the option of the VortecMax engine was 2009 in the Silverado and Sierra. vin code (Y)
The L98 is a slightly modified version of the L76. 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 362 bhp (270 kW) at 5700 rpm and 391 lb·ft (530 N·m) at 4400 rpm.
L77 engines were released in the Holden Commodore Series II VE range in both manual and automatic transmissions, along with the Chevrolet Caprice police car. The L77 differs from the L76 with its inclusion of Flex-fuel capability, allowing it to run on E85 ethanol. The L77 is rated at 361 hp (269 kW) and 385 lb·ft (522 N·m) of torque.
The LFA 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 332 hp (248 kW) at 5100 rpm and 367 lb·ft (498 N·m) at 4100 rpm. Engine VIN code of 5.
In 2008 this engine was selected by Wards as one of the 10 best engines in any regular production vehicle (see http://en.wikipedia.org/wiki/Ward's_10_Best_Engines).
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, power and torque ratings as its predecessor, the LFA.
This family of blocks is just 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.
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 96.01 mm (3.780 in) bore and 83 mm (3.3 in) stroke. The smallest member of the Generation IV engine family, it is unique in that it is the only member of that family that is used in trucks that does not feature either variable valve timing.It has a cast iron block. Power output is 260–295 hp (194–220 kW) and torque is 295–305 lb·ft (400–414 N·m).
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 260–302 hp (194–225 kW) while torque is 295–305 lb·ft (400–414 N·m). The Vortec 4800 base engines were dropped from the Chevrolet Tahoe and GMC Yukon in favor of the 5300 with Active Fuel Management.
First introduced in 1999, the Generation IV Vortec 5300 engines share all the improvements and refinements found in other Generation IV engines. At present, four versions of the 5300 engine in production: 2 iron blocks (LY5 and LMG) and 4 aluminum blocks (LH6, LH8,LH9 and LC9). All versions feature Active Fuel Management except for the LH8, LH9.
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 315 hp (235 kW) and 338 lb·ft (458 N·m). It is the aluminum block counterpart to the 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 320 hp (239 kW) and 340 lb·ft (461 N·m) of torque; for pickup truck applications, it is rated at 315–320 hp (235–239 kW) at 5200 rpm and 335–340 lb·ft (454–461 N·m) at 4000 rpm
The Vortec 5300 LMG (VIN code "0") is the flexible-fuel version of the LY5. Power and torque ratings for SUV and pickup truck applications are the same as each application's LY5 rating.
The Vortec 5300 LC9 (VIN code "3") is the Flex-Fuel version of the LH6, and is found in 4WD models. SUV applications are rated at 320 hp (239 kW) @ 5400 rpm and 335 lb·ft (454 N·m) @ 4000 rpm of torque. Pickup truck applications are rated at 315 hp (235 kW) @ 5300 rpm and 335 lb·ft (454 N·m) @ 4000 rpm of torque.
The Vortec 5300 LH8 is a variant of the 5.3 L Gen IV small block V8 modified to fit in the engine bay of the GMT 345 SUV and GMT 355 trucks. It produces 300 hp (220 kW) at 5200 rpm and 320 lb·ft (434 N·m) at 4000 rpm. It has a displacement of 5,328 cc (325.1 cu in).
The Generation IV Vortec 5300 engines are truck engines that share all the improvements and refinements found in other Generation IV engines. At present, four versions of the 5300 are in production: two iron block versions (LY5 and LMG) and two aluminum block versions (LH6 and LC9). All versions feature the Active Fuel Management system, and starting with MY 2010, variable valve timing (engine RPO codes stayed the same).
The LS4 is a 5,328 cc (5.328 L; 325.1 cu in) 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 it uses the same cylinder head as the Generation III LS6 engine. The bellhousing bolt pattern differs from the rear-wheel drive blocks.
This engine is adapted for transverse front-wheel drive applications. According to GM, "The crankshaft is shortened 13 mm – 3 mm at the flywheel end and 10 mm at the accessory drive end – to reduce the length of the engine compared to the 6.0L. 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 303 hp (226 kW)/300 hp on LaCrosse Super and 323 lb·ft (438 N·m).
Inspired by the LS1.R in size and performance goals, this family of blocks was designed for race oriented performance. The only block that is in production 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.
The LS7 is a 7,008 cc (7.008 L; 427.7 cu in) engine, based on the Gen IV architecture. The block is changed, with sleeved cylinders and a larger 4.125in (104.775mm) bore and longer 4.00in (101.6mm) stroke than the LS2. The small-block's 4.4 in (110 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. The two-valve arrangement is retained, though the titanium intake valves by Del West have grown to 2.20 in (56 mm) and sodium-filled exhaust valves are up to 1.61 in (41 mm).
Peak output is 505 hp (377 kW) at 6300 rpm and 470 lb·ft (640 N·m) at 4800 rpm with a 7100 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, due to the constraints of the camshaft's hydraulic lifters and the intake manifold ability to flow required air at that engine speed.
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 375 kW (503 hp) and 640 N·m (470 lb·ft), at the time making it the most powerful car ever built in Australia. The W427 was unveiled at the Melbourne International Motor Show on 29 February 2008 and went on sale in August 2008.
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 good performance. This family of engines has mainly seen duty in performance cars and high-end SUVs.
The 2007 Cadillac Escalade has a 6.2 L Vortec 6200 (RPO L92) (≈379 cu in) engine. It is an all-aluminum design which, while still a pushrod engine, boasts variable valve timing. The system adjusts both intake and exhaust timing between two settings. This engine produces 403 hp (301 kW) and 417 lb·ft (565 N·m) in the GMC Yukon Denali/XL Denali, Sierra SLT, and in the GMC Sierra Denali, and rated at 403 hp (301 kW) and 415 lb·ft (563 N·m) (441 hp with 93 octane[clarification needed] export version) in the Hummer and in the Cadillac Escalade. It is also available in the Chevrolet Silverado and Tahoe LTZ, with power ratings of 403 hp (301 kW) and 417 lb·ft (565 N·m) .The L92 was modified with Flex Fuel capability for MY 2009 and became the L9H, and was further modified with Active Fuel Management for MY 2010 (and becoming the L94) in the Cadillac Escalade and GMC Yukon Denali's.
The LS3 was introduced as the Corvette's new base engine for the 2008 model year. It produces 430 bhp (321 kW; 436 PS) at 5900 rpm and 424 lb·ft (575 N·m) 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 4.06 in (103 mm) creating a displacement of 6,162 cc (6.162 L; 376.0 cu in). It also features higher flowing cylinder heads sourced from the L92, a more aggressive camshaft with 0.551-inch (14.0 mm) lift, a 10.7:1 compression ratio, a revised valvetrain with 6 mm (0.24 in) offset intake rocker arms, a high-flow intake manifold and 47 lb/hr fuel injectors from the LS7 engine.
The L76/L92/LS3 cylinder heads use 2.165 in (55.0 mm) intake valves, and 1.59 in (40 mm) exhaust valves. Improved manufacturing efficiency makes these heads cheaper than the outgoing LS6 heads, and severely undercuts 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 is available. 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 2.5 in (64 mm) diameter exhaust compared to the Z06's 3 in (76 mm). Power is boosted to 436 hp (325 kW) and 428 lb·ft (580 N·m) with this option.
From April 2008, Australian performance car manufacturer, HSV, adopted the LS3 as its standard V8 throughout the range, replacing the LS2. The LS3 received modifications for its application to HSV E Series models, producing 425 bhp (317 kW). The LS3 engine in the E Series II GTS (released September 2009) was upgraded to produce 436 bhp (325 kW). All HSV MY12.5 excluding the base Maloo and Clubsport variants have been upgraded to produce 436 bhp (325 kW).
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.
The Gen IV LS9 is a supercharged 6,162 cc (6.162 L; 376.0 cu in) engine, based on the LS3; the LS7 block was not used due to the higher cylinder pressures created by the supercharger requiring the thicker cylinder walls of the LS3. Cylinder dimensions are now 4.06 in (103 mm) bore and 3.62 in (92 mm) stroke. It is equipped with an Eaton four-lobe Roots type supercharger and has a compression ratio of 9.1:1. Power output is rated 638 bhp (476 kW) at 6500 rpm and 604 lb·ft (819 N·m) at 3800 rpm. Note: GM previously used the LS9 RPO code on 1969 and later Chevrolet trucks (both 2WD and 4WD) including Blazers, Jimmys, Suburbans, as well as car carriers. The original LS9 was a 350 cu in V8, developing 160 hp and 245 Ft/lbs of torque.
The supercharged 6.2L LSA is similar to the LS9 and debuted in the 2009 CTS-V. The LSA has been SAE certified at 556 bhp (415 kW) at 6100 rpm and 551 lb·ft (747 N·m) at 3800 rpm. GM labels it "the most powerful ever offered in Cadillac’s nearly 106-year history". The LSA features a smaller 1.9L capacity supercharger rather than the 2.3 L variant of the LS9. Other differences include a slightly lower 9.0:1 compression ratio, single unit heat exchanger and cast pistons.
A 580 bhp (430 kW) and 556 lb·ft (754 N·m) version of the LSA engine is used in the 2012 Camaro ZL1. On 15 May 2013, Holden Special Vehicles announced that this version of the LSA engine will also be used in the GEN-F GTS.
|Cylinder block alloy||Aluminum|
|Cylinder head alloy||Aluminum|
|Fuel system||Direct injection|
|Oil system||Wet sump|
The first Gen 5 LT engine was the LT1, announced in 2012 as the initial powerplant for the redesigned C7 Corvette, succeeding the LS engine family. The new logo formally adopts the Small Block name for the engines. In early 2014, the second Gen 5 engine was introduced, also for the Corvette and would be named the LT4. It would also be 6.2 liters with the same bore and stroke of the LT1, but with a supercharger and lower-compression pistons, for an engine that will crank up to 650 horsepower and can deliver 650 lb.-ft. of torque at 3,600 rpm. The supercharger added 1 inch to the overall height of the LT1.
It includes features such as direct injection, piston cooling jets, active fuel management, variable displacement oil pump, continuously variable valve timing and aluminum cylinder heads and block. However, it does retain its ancestors' 2-valve pushrod valvetrain.
In 2007, wardsauto.com reported that the LS3 (used by 2008 Chevrolet Corvette) and Vortec 6000 LFA (used by 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 L92 engine from Cadillac Escalade, GMC Yukon Denali and Hummer H2, and reported to generate 450 bhp (340 kW) on gasoline via direct fuel injection, increased compression ratio to 11.5:1, and a modified engine controller. In 2012, the first Small Block Gen 5 (official designation), designated LT1, was announced as the powerplant for the C7 Corvette. The new logo formally adopts the Small Block name for the engines. In early 2014, the media was notified that the next Gen 5 engine for the Corvette would be named the LT4, another 6.2 liter with the same bore and stroke of the LT1, but with a supercharger and lower-compression pistons, with the redline not increased by much if at all, for a reported 625 horsepower and 635 pounds-feet so far (as of January 2014), whilst the supercharger added 1 inch to the overall height of the LT1. The Gen 5 also includes a 90 degree V6 variant displacing 4.3L - destined to replace the 1978-era Chevrolet 90 degree V6.
In the early production run of the LS-series engine, some engines encountered 'piston slap' during the first couple minutes after a cold engine start - this sound is caused by the very efficient, light weight, short skirt 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. The noise of 'piston slap' often is louder when listening for it below the oil pan.
Another common problem with the 2001-2006 5.3L engines was cracking cylinder heads. This is commonly called the 'Castech Head' failure on the internet. GM issued a TSB on this failure to help service techs identify the problem. The head casting (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.
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, Mich., 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, were 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.
The LS7.R engine is a variation of the LS7 used in the highly successful C6.R American Le Mans Series racecar. It was crowned as Global Motorsport Engine of the Year by a jury of 50 race engine engineers on the Professional Motorsport World Expo 2006 in Cologne, Germany.
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 364 cubic inches to 511 cubic inches (4.25 in (108 mm) Bore x 4.5 in (110 mm) Stroke) and is capable of withstanding 2,500 bhp (1,900 kW). 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 will be available starting the second quarter of 2007, set to be available in authorized dealerships and retailers on March 31, 2007.
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 4.200-inch bore still allows 0.200-inch 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 3.880 is ready for final boring/honing.
Chevrolet Performance LSX376 crate engines are updated versions of LSX crate engine family designed to support up to 1,000 horsepower. All models use Chevrolet Performance LSX Bowtie block.
LSX376-B15 (part number 19299306) includes forged steel crankshaft, forged H-beam rods and forged aluminum pistons (9.0:1 compression), high-flow rectangular-port six-bolt LSX-LS3 heads for supercharged and turbocharged combinations producing up to 15 pounds of boost and up to about 1,000 horsepower.
LSX376-B8 (part number 19171049) is a more economical version that is capable of approximately 8 pounds of boost, for engine producing approximately 600 horsepower. It is designed for production-style supercharger and turbo systems used without enhancements or modifications.
|Engine Code||Power (hp)||Torque (lb.-ft.)||Redline (rpm)||Displacement (L)||Fuel||Bore (in)||Stroke (in)||Compression Ratio||MPG City / Hwy / Combined|
|LS7||505 @ 6200||475 @ 4800||7000||7.0||91||4.125||4.00||11.0:1 |
|LS2||400 @ 6000||400 @ 4400||6.0||93||4.00||3.62||10.9:1||19/28/23|
|LS9||638 @ 6500||604 @ 3800||6600||6.2||92||4.065||3.62||9.1:1||MPG|
|LS1||350 @ 6000||360 @ 4000||6000||5.7||Fuel||3.90||3.62||10.25:1||MPG|
|LS6||385-405 @ 6000||400 @ 4800||6500||5.7||Fuel||3.90||3.62||10.5:1||MPG|
|LS3||426 @ 5900||420 @ 4600||6600||6.2||Fuel||4.06||3.62||10.7:1||16/24/|
|L99||400 @ 5900||410 @ 4300||6200||6.2||Fuel||4.06||3.62||10.4:1||16/25/|
|LSA||550 @ 6100 (est)||550 @ 3800 (est)||6200||6.2||Fuel||4.06||3.62||9.1:1||MPG|
|LSX376||450 @ 5900||444 @ 4600||6600||6.2||92||4.06||3.62||9:1||MPG|
|LSX454||620 @ 6200||590 @ 4800||6500||7.4||92||4.185||4.125||11.0:1||MPG|
|LSX454R||770 @ 7000||612 @ 4500||6500||7.4||92||4.185||4.125||13.1:1||MPG|
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