The LS series is a new design intended as the only V-8 engine utilized in General Motors' line of RWD cars and trucks. The LS series was a clean sheet design with little in common with the classic Chevrolet small block V8. The LS is all-aluminum and has 6-bolt main bearing caps.
The LS engine has been the sole powerplant of the Chevrolet Corvette since 1997 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 kit cars, hot rods, buggies, and even light aircraft.
The Generation III V-8 engines replaced the LT family in 1997. 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 structurely 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 preious two generations. The engine also introduced coil-on-plug ignition. The traditional five-bolt pentagonal cylinder head pattern was replaced with a square four-bolt design, and the pistons are of the flat-topped variety(In the LS1, LS2, LS3, LS6, LS7, LQ9 and L33) all other motors including the new LS9 received a dished version of the GM hyperutectic 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 LS1 was rated at 350 hp (260 kW) and 365 lb·ft (495 N·m) in North America, depending on the application. The LS1 was used in the Corvette from 97-04. It was also used in GM F-Body cars with a falsely low rating of 315HP. 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 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)@6000rpm and 400 lb·ft (542 N·m)@4400rpm 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 LS2s in the E-series HSVs are modified in Australia to produce 412 bhp (307 kW) and 412 lb·ft (559 N·m). The LS2s 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 LS3 was introduced as the Corvette's new base engine for the 2008 model year. It produces 430 bhp (320 kW)@5900rpm and 424 lb·ft (575 N·m)@4600rpm 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 (103.1 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" lift, 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 mm) intake valves, and 1.59 in (40.4 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 (63.5 mm) diameter exhaust compared to the Z06's 3 in (76.2 mm). Power is boosted to 436 hp (325 kW) and 428 ft·lbf (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's models, producing 425 bhp (317 kW). Power and torque was restricted to protect the drivetrain currently used in the E-Series sedans.
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 LH6, it differs in that it has an aluminum block rather than an iron one and it uses the same cylinder head as the Generation III LS6 engine.
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."[4] 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).
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 lb·ft (522 N·m), but the engine was modified for 2002 through 2004 to produce 405 bhp (302 kW) and 400 lb·ft (542 N·m) of torque. The LS6 was originally only used in the high-performance C5 Corvette Z06 model, with the Cadillac CTS V-Series getting the 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, sodium filled valves, and a revised oiling system better suited to high lateral acceleration.[2]
A number of LS6 intake manifolds were also used on some 2001-2002 Chevrolet Camaros.
The casting number, located on the top rear edge of the block, is 12561168.
The LS7 is a 7,011 cc (7.011 L; 427.8 cu in) engine, based on the Gen IV architecture. The block is changed, with sleeved pistons and a larger 4.125 in (104.8 mm) bore and longer 4.00 in (101.6 mm) stroke than the LS2. The small-block's 4.4 in (111.8 mm) bore spacing is retained, requiring pressed-in cylinder liners. The crankshaft and main bearing caps are forged steel for durability, the connecting rods are forged titanium, and the pistons are hypereutectic. The two-valve arrangement is retained, though the titanium intake valves by Del West have grown to 2.20 in (55.9 mm) and sodium-filled exhaust valves are up to 1.61 in (40.9 mm).
Peak output is 505 hp (377 kW) at 6300 rpm and 470 lb·ft (640 N·m) at 4800 rpm with a 7000 rpm redline[citation needed] 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 made at that rpm level, due to the constraints of the camshaft's profile and the intake manifold ability to flow required air at that engine speed.
The LS7 is hand-built by the General Motors Performance Build Center in Wixom, Michigan. Most of these engines are installed in the Z06, but some are also sold to individuals by GM as a crate engine.
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 produces 375kW (503hp) and 640 N·m (470 lb·ft), making it the most powerful car ever built in Australia. The W427 was unveiled at the Melbourne International Motor Show on 29 February, 2008[5] and went on sale in August 2008.
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.
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 (114.3 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.[6]
LS9
The LS9 RPO code was originally used on 69 and up Chevy trucks, available in 2 and 4 wheel drives, Blazers, Jimmys, and Suburbans. The original LS9 was a 350 cu in V8. 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 (103.1 mm) bore and 3.62 in (91.9 mm) stroke. It is equipped with an Eaton four-lobe Roots type supercharger. Power output is rated 638 bhp (476 kW)@6500rpm and 604 lb·ft (819 N·m)@3800rpm.
Applications:
LSA
The supercharged 6.2L LSA is similar to the LS9 and debuted in the 2009 Cadillac CTS-V. The LSA has been SAE certified at 556 bhp (415 kW)@6100rpm and 551 lb·ft (747 N·m)@3800rpm. 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 2.3L variant of the LS9. Other differences include a slightly lower 9.0:1 compression ratio, single unit heat exchanger and cast pistons. |
