GEN III
The Generation III small-blocks replaced the LT family in 1997. These shared the same rough displacement and bore spacing (4.4 in) as their cast iron predecessors but almost everything else 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. Even the cylinder firing order was changed.
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 N·m) of torque. It shares its block with the higher-output LS6. The LS1 was on the Ward's 10 Best Engines list for 1998.
It is used in the following vehicles:
LS6
- LS6 can also refer to a 454 in³ Chevrolet Big-Block engine of the 1970s
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 N·m) 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 basic block design with the GM LS1 engine, but other changes were made such as windows cast into the block between cylinders. 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.
V8
4800
The Vortec 4800 LR4 is a V8 truck engine. Displacement is 4.8 L (4807 cc) with a 96.01 mm bore and 83 mm stroke. It is a de-bored and de-stroked cast iron version of the LS1 small-block from the Corvette with aluminum cylinder heads. It replaced the 5.0 L 5000 L30 for the 2003 full-size vans. The LR4 produces 270-275 hp (201-205 kW) and 285-290 ft.lbf (386-393 Nm) of torque. LR4s are manufactured at St. Catharines, Ontario and Romulus, Michigan.
The LR4 features electronic throttle control and does not need exhaust gas recirculation due to a new, more-powerful computer. The LR4 shares the same block and cylinder heads as the Vortec 5300.
LR4 applications:
5000
The Vortec 5000 L30 is a V8 truck engine. Displacement is 5.0 L. It is a based on the Generation I small-block from Chevrolet. It was replaced by the 4.8 L 4800 LR4 for the 2003 full-size vans.
L30 applications:
5300
The Vortec 5300, or LM7/LM4/L59, is a V8 truck engine. It is a stroked (by 9 mm) version of the Vortec 4800 and replaced the 5700 L31 in 2003. L59 denotes a flexible fuel version, while the LM7 is a special low-emmissions engine. The L33 is made for the pickup trucks.
All Vortec 5300s are based on the new Generation III small-block V8. Unlike the all-aluminum LM4 and L59, the LM7 uses a cast iron block. The block and heads are the same as on the 4800 LR4. Power output is 285-295 hp (213-220 kW) and torque is 325-330 ft.lbf (441-447 Nm). Displacement is 5.3 L (5328 cc) from 96.01 mm bore and 92.00 mm stroke. Vortec 5300s are built in St. Catharines, Ontario, Romulus, Michigan, and Silao, Mexico.
LM7 (iron block, low-emmissions) applications:
LM4 (all-aluminum) applications:
L33 applications:
L59 (flexible-fuel, allowing E85) applications:
LH6
An improved LH6 version with Displacement on Demand will push output even higher. It is a Generation IV small-block and features the improvements found on other Gen4 motors. An early batch of fifty 2005 Saab 9-7X SUVs for the Canada market used this engine with the Displacement on Demand feature disabled.
LH6 applications:
An automotive version of the 5300 V8 will also be offered in the Pontiac Grand Prix in 2005.
5700
The Vortec 5700 L31 is a V8 truck engine. Displacement is 5.7 L. It is a based on the Generation I small-block from Chevrolet. It was replaced by the 5.3 L 5300 LM7 for the 2003 full-size vans.
L31 applications:
A 5.7 L small-block was also used in the GMT800 SUVs. This was replaced by the 6.0 L Vortec 6000.
Applications:
6000
The Vortec 6000, or LQ4, is a V8 truck engine. It is a bored version of the Vortec 5300. Displacement is 6.0 L (5967 cc) from 101.6 mm bore and 92 mm stroke. It is an iron/aluminum design and produces 300-325 hp (224-242 kW) and 360-370 ft.lbf (488-502 Nm). LQ4s are built in Romulus, Michigan and Silao, Mexico.
LQ4 applications:
HO 6000
The Vortec HO 6000, or LQ9, is a special high-output version of the Vortec 6000 V8 truck engine for Cadillac. It features high-compression (10:1) flat-top pistons for an extra 10 hp and 10 ft.lbf, bringing output to 345 hp (257 kW) and 380 ft.lbf (515 Nm). LQ9s are built only in Romulus, Michigan.
LQ9 Applications:
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GEN 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 ranges up to 7.0 L and output to 500 hp (373 kW). Generation IV will later 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 400 hp (298 kW) at 6000 rpm and 400 ft·lbf (542 N·m) at 4400 rpm from a new 6.0 L V8 based on the old LS1. It is similar to the high-performance LS6, and a higher-performance version of this engine is called the LS7.
Applications:
LS4
The LS4 is a smaller 5.3 L 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.
A version of this engine is adapted for transverse front wheel drive application, the first time a small-block family engine has been used in this manner since the Oldsmobile Aurora of the late 90s, it had a 4.0L V8. Displacement on Demand is also used. Output of this version is 303 hp (226 kW) and 323 ft·lbf (438 N·m).
Applications:
LS7
The LS7 is the latest high-power LS engine. It is a 7.0 L (7008 cc) unit, based loosely on the LS2. The block is changed, with a larger 4.13 in (104.9 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 titanium, however cast pistons were retained to avoid the piston slap issues that forged pistons have on startup. The two-valve arrangement is retained, though the titanium intake valves 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 ft·lbf (637 N·m) at 4800 rpm with a 7000 rpm redline.
The LS7 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.
The 7.0 L mark had already been reached by the LS-series of racing engines, famously in the 24 Hours of Le Mans Corvette C5R. GMMG Berger Camaro ZL1s made late in 2002 and GMMG Berger Dick Harrell Camaros (inspired by the Penske Donahue concept car) also featured variations of the 7.0 L size.
Applications: 2006 Corvette Z06
Chevrolet also had an experimental big-block engine named LS7 in the late 60's that were supposed to be in the 1970 Corvette, but it never materialized. Some LS7 heads were sold as an aftermarket product in 1971 and 1972 though.
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