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Atlas is a name for a family of modern inline piston engines for trucks from General Motors. The series debuted in 2002 with the Oldsmobile Bravada, and is also used in the Chevrolet TrailBlazer and Colorado and their GMC twins, the Envoy and Canyon. In production, the engines use GM's Vortec name, and I4, I5, and I6 engines are all part of the same family, sharing the same manufacturing equipment, rods, pistons, valves, and other parts. They feature variable valve timing on the exhaust side, electronic throttle control, and a special oil pan with a pass-through for the half shafts in four-wheel drive vehicles. The inclusion of VVT on the exhaust allows the Atlas series to meet emissions standards without the use of EGR, simplifying the engine design.

The Atlas program began in 1995 along with the planning for GM's next-generation mid-size SUVs and pickup trucks. These vehicles were designed around the I6 engine. The I6 version was used in a Baja 2000 racing truck, winning its first race in a class that also included V8 engines. Another I6-powered truck won the truck class at the Pikes Peak International Hillclimb.

The I6 Atlas engines are produced at the Flint Engine South plant in Flint, Michigan, while the I4 and I5 versions are produced at the Tonawanda Engine plant in Tonawanda, New York.

[edit] LL8

Vortec 4200 LL8 engine in a 2006 Chevrolet Traiblazer.

The LL8 (or Vortec 4200), is a straight-6 truck engine. It was the first Atlas engine, and was designed for GM's new SUV line. It displaces 4.2 L (4160 cc, 254 cu in)^[1], with a 93 mm (3.7 in) bore and 102 mm (4 in) stroke. When introduced, this engine's power was 270 hp (205 kW) @ 6000 rpm and torque was 275 ft·lbf (373 N·m) @ 3600 RPM. 2003 saw a slight bump in power to 275 hp (205 kW), while torque was unchanged. For 2006, power was increased to 291 hp (217 kW) @ 6000 rpm and torque to 277 ft·lbf (376 N·m) @ 4800 rpm with the addition of a MAF and a complete internal redesign of the engine. The Atlas LL8 was on the Ward's 10 Best Engines list for 2002 through 2005. Engine redline is 6300 rpm.

LL8 Applications:

• 2002-2007 GMC Envoy, Envoy XL, and Envoy XUV
• 2002-2007 Chevrolet TrailBlazer and TrailBlazer EXT
• 2002-2004 Oldsmobile Bravada
• Buick Rainier
• Isuzu Ascender
• Saab 9-7X

[edit] L52

L52

Also called	Vortec 3500
Type	straight-5
Bore	93 mm (3.7 in)
Stroke	102 mm (4 in)
Displacement	3,460 cc (211 cu in)
Power output	220 hp (164 kW) @ 5600 RPM
Torque output	225 lb·ft (305 N·m) @ 2800 RPM

The L52 (also called Vortec 3500), is a straight-5 truck engine. It displaces 3.5 L (3,460 cc/211 cu in), with a 93 mm (3.7 in) bore and 102 mm (4 in) stroke, and shares much with the rest of the Atlas family. Dynoed at the flywheel it produces 220 hp (164 kW) @ 5600 rpm and also dynoed at the flywheel 225 ft·lbf (305 N·m) @ 2800 rpm. Engine redline is 6300 rpm. While producing 179.13 hp at 6001 rpm when dynoed at the rear wheels.

It is used in the following vehicles:

• 2002 Chevrolet Bel Air concept
• 2004-2006 Chevrolet Colorado
• 2004-2006 GMC Canyon
• 2006 Isuzu i-Series
• 2006 Hummer H3

[edit] LLR

The LLR (also called Vortec 3700), is a straight-5 truck engine. It displaces 3.7 L (3,653 cc/223 cu in), courtesy of a larger 95.5 mm (3.76 in) bore while keeping the 102 mm (4 in) stroke, and shares much with the rest of the Atlas family. It produces 242 hp (180 kW) @ 5600 rpm and 242 ft·lbf (327 N·m) @ 4600 rpm. Engine redline is 6300 rpm.

It is used in the following vehicles:

• 2007 Chevrolet Colorado
• 2007 GMC Canyon
• 2007 Isuzu i-Series
• 2007 Hummer H3

[edit] LK5

The straight-4 LK5 engine is sold as the Vortec 2800 in GM trucks. Like its Atlas brothers, the LK5 has dual overhead cams, and shares their 93 mm (3.7 in) bore and 102 mm (4 in) stroke. The LK5 displaces 2.8 L (2770 cc, 169 cu in) and produces 175 hp (131 kW) @ 5600 rpm and 185 ft·lbf (251 N·m) @ 2800 rpm.^[2] Engine redline is 6300 rpm.

It is used in the following vehicles:

• 2004-2006 Chevrolet Colorado
• 2004-2006 GMC Canyon
• 2006 Isuzu i-Series

[edit] LLV

The straight-4 LLV engine is sold as the Vortec 2900 in GM trucks. It shares the same 95.5 mm bore and 102 mm (4 in) stroke as the LLR Vortec 3700. The LLV displaces 2.9 L (2921 cc, 178 cu in)^[3] and produces 185 hp (138 kW) @ 5600 rpm and 195 ft·lbf (263 N·m) @ 2800 rpm. Engine redline is 6300 rpm.

It is used in the following vehicles:

• 2007 Chevrolet Colorado
• 2007 GMC Canyon
• 2007 Isuzu i-Series