The LS is Generation III and Generation IV, the latest evolution of General Motors' line of small-block V8 engines. The LS series is an evolution of the LT family but is all-aluminum and has 6-bolt mains. The LS engine has been the sole powerplant of the Chevrolet Corvette, and has also been used in the Pontiac GTO, the Cadillac CTS V-series, and the late Camaro/Firebird V8 models.
Generation III
The Generation III small-blocks replaced the LT family in 1998. These shared the same rough displacement and bore spacing (4.4 in) but much was changed. The bore was reduced to 3.9 in and the stroke longer at 3.62 in for greater torque. The block was cast from aluminum (for cars) instead of iron and had a new intake and injection technology and coil-on-plug ignition. The traditional five-bolt pentagonal cylinder head pattern was replaced with a square four-bolt design, and the pistons are flat instead of domed.
LS1
The LS1 was an evolution of the earlier LT small-block V8 (and is almost identical to the LT4 except for its aluminum construction). It is an all-aluminum 5.7 liter (5665 cc) pushrod engine and produces 350 hp (261 kW) and 375 ft.lbf (508 Nm) of torque. It shares its block with the higher-output LS6.
It is used in the following vehicles:
- 1997-2004 C5 Corvette base model
- 1998-2002 Chevrolet Camaro Z28, SS
- 1998-2002 Pontiac Firebird Formula and Trans-Am
- 2004 Pontiac GTO
LS6
The LS6 is a higher-output version of Chevrolet's small-block LS1 engine. It is an all-aluminum 5.7 liter (5665 cc) pushrod engine and produces 405 hp (302 kW) and 400 ft.lbf (542 Nm) of torque. It is used in the high-performance C5 Corvette Z06 model and the Cadillac CTS V-Series. The C6 Corvette Z06 will get a new LS7.
The LS6 shares its block with the GM LS1 engine, but other changes were made. Improved intake, a titanium exhaust, higher-lift cams, and higher compression boosts output, and a new oiling system is better suited to high lateral acceleration.
Vortec engines
The Vortec 4800, 5300, and 6000 are cast-iron versions of the LS1 engine with different bore and stroke dimensions.
Generation IV
Hot on the heels of the Generation III was Generation IV. These big-bore engines are some of the largest small-blocks yet, and will quickly replace the previous generation. Displacement is said to range up to 6.3 L and output to 500 hp (373 kW). Generation IV will feature displacement on demand, a technology that allows one bank of cylinders to be deactivated. It will also offer variable cam phasing and 3-valve per cylinder designs, a novelty in a pushrod engine.
LS2
The LS2 is the new base engine in the Corvette. It produces 405hp and 400lbft from a new 6.0 liter V8 based on the old LS1. It is similar to the high-performance LS6, and a higher-performance version of this engine will be called the LS7.
The LS2 debuted in the 2005 Chevrolet Corvette, and will be used in the 2005 Pontiac GTO and the 2005 Chevrolet SSR.
LS4
The LS4 is a smaller 5.3 L version of the Generation IV block. It is sold for use in trucks as the vortec 5300 LH6.
LS7
The LS7 is the latest high-power LS engine. It is based on the LS2 but is said to be much more powerful. It might even be the first twin-cam pushrod engine. It will be hand-built by the General Motors Performance Build Center in Wixom, Michigan. Up to 15,000 LS7s will be produced each year starting in 2005. Displacement may range from 6.3L to 7.0L. The 7.0L mark has already been reached in the LS engine series of engines and is most noted in the GMMG Berger Camaro ZL1 made late in 2002 and in the latest GMMG Berger project, the Dick Harrell edition Camaro developed in mid-2004 based on Camaro LS1 cars not yet sold in the dealer network.
See also
- GM Small-Block engine - Generation I
- GM LT engine - Generation II
- Chevrolet Corvette