Also called Vortec Cylinder block alloy Aluminum | Production 2002–2012 | |
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Manufacturer General Motors Corporation Configuration straight-4straight-5straight-6 Displacement 169-254 cu in (2770-4160 cc) | ||
Atlas is a name for a family of modern inline piston engines for trucks from General Motors, used in the GMT 355 and GMT360 platforms. The series debuted in 2002 with the Oldsmobile Bravada, and is also used in the Buick Rainier, the Chevrolet TrailBlazer and Colorado, the GMC Envoy and Canyon, the Hummer H3, Isuzu Ascender and i-370, and the Saab 9-7X. 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 camshaft side allows the Atlas series to meet emissions standards without the use of EGR, simplifying the engine design and increasing power for a broad power curve. The LL8 shares 75% of its components with the LK5 and L52; while the LK5 and L52 share 89% of their components.
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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 were produced at the Flint Engine South plant in Flint, Michigan, while the I4 and I5 versions were produced at the Tonawanda Engine plant in Tonawanda, New York, near Buffalo.
LL8
The LL8 (or Vortec 4200), is a straight-6 gasoline engine. It was the first Atlas engine, and was introduced in 2002 for the Chevrolet TrailBlazer, GMC Envoy, and Oldsmobile Bravada, the engine is also in use in the Buick Rainier, Saab 9-7, and the Isuzu Ascender. It displaces 4,160 cc (254 cu in), with a 93 mm (3.7 in) bore and 102 mm (4.0 in) stroke. It has four valves per cylinder, utilizes dual-overhead cams DOHC design, and features variable valve timing on the exhaust cam, a first for GM Inline engines. When introduced, this engine's power was 270 hp (200 kW) at 6000 rpm and torque was 275 lb·ft (373 N·m) at 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) at 6000 rpm and torque to 277 lb·ft (376 N·m)) at 4800 rpm with the addition of a MAF and a complete internal redesign of the engine; however due to the new SAE rating procedures ratings can vary slightly between years. Engine redline is 6300 rpm. The LL8 was on the Ward's 10 Best Engines list for 2002 through 2005 and was the basis for all the other Atlas engines. With the closing of the Moraine, Ohio plant and the termination of the GMT360 platform (Chevrolet TrailBlazer, GMC Envoy, etc.) the production of the LL8 was also terminated.
Applications:
L52
The L52 (also called Vortec 3500), is a straight-5 DOHC engine. It displaces 3,460 cc (211 cu in), with a 93 mm (3.7 in) bore and 102 mm (4.0 in) stroke. Dynoed at the flywheel it produces 220 hp (160 kW) at 5600 rpm and 225 lb·ft (305 N·m) at 2800 rpm, while producing 179.13 hp (133.58 kW) at 6001 rpm when dynoed at the rear wheels. Engine redline is 6300 rpm.
Applications:
LLR
The LLR (also called Vortec 3700), is a straight-5 DOHC engine. It displaces 3,653 cc (223 cu in), courtesy of a larger 95.5 mm (3.76 in) bore while keeping the 102 mm (4.0 in) stroke. The LLR also corrected the head issue found in the L52. It produces 242 hp (180 kW) at 5600 rpm and 242 lb·ft (328 N·m) at 4600 rpm. Engine redline is 6300 rpm.
Applications:
LK5
The LK5 (also called the Vortec 2800) is a 2,770 cc (169 cu in) straight-4 DOHC engine, with a 93 mm (3.7 in) bore and 102 mm (4.0 in) stroke. It produces 175 hp (130 kW) at 5600 rpm and 185 lb·ft (251 N·m) of torque at 2800 rpm. The engine redline is 6300 rpm.
Applications:
LLV
The LLV (also called Vortec 2900) is a 2,921 cc (178.3 cu in) straight-4 DOHC engine, with a 95.5 mm (3.76 in) bore and a 102 mm (4.0 in) stroke. It replaced the LK5 and produced 185 hp (138 kW) at 5600 rpm and 190 lb·ft (258 N·m) of torque at 2800 rpm. Engine redline is 6300 rpm.
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