Atlas is a name for a family of modern inline piston engines for

truck A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame constructi ...

s from General Motors, used in the GMT355 and

GMT360 GMT 360 is a vehicle platform that was manufactured by General Motors from the 2002 and 2009 model years. Designed primarily for SUVs, the GMT360 architecture served as the third generation of mid-size SUVs produced by GM. Directly succeeding i ...

platforms. The series debuted in 2002 with the

Oldsmobile Bravada The Oldsmobile Bravada is a four-door mid-size SUV manufactured and marketed by the Oldsmobile division of General Motors. The Bravada was built across three generations as a rebadged variant of the Chevrolet Blazer and GMC Jimmy. It was the on ...

, and is also used in the

Buick Rainier The Buick Rainier is a mid-size luxury SUV that was manufactured by General Motors and marketed by Buick for model years 2004–2007. It was named after Mount Rainier, and — along with the Saab 9-7X — was the replacement for the Oldsmobile ...

, the

Chevrolet TrailBlazer The Chevrolet Trailblazer is an automobile nameplate used by General Motors for its Chevrolet brand since 1999 for several SUV models: * TrailBlazer, a name of appearance package for the Chevrolet S-10 Blazer used between 1999 and 2002 * Chevro ...

and

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

, the

GMC Envoy The GMC Envoy is a mid-size SUV, manufactured and marketed by General Motors for model years 1998-2009 over two generations. Adopting a nameplate used by GM Canada, the Envoy was a rebadged variant of the Chevrolet TrailBlazer, Oldsmobile Brava ...

and Canyon, the

Hummer H3 The Hummer H3 is an off-road vehicle that was produced from 2005 to 2010 by General Motors. The smallest model of the Hummer lineup, it was offered as a 5-door SUV or a 4-door pickup truck known as the H3T. Unlike the larger H1 and H2 models, t ...

Isuzu Ascender The Isuzu Ascender is a mid-size SUV built by General Motors for Isuzu. The 7-passenger Ascender was introduced for the 2003 model year as a replacement for the Isuzu Trooper. The 5-passenger Ascender was introduced for the 2004 model year as a ...

and i-370, and the

Saab 9-7X The Saab 9-7X is a mid-size luxury SUV that was built by General Motors for the American market and sold under the Saab marque. The 9-7X was first revealed at the 2004 New York International Auto Show, and was available starting in the model y ...

. The engines use GM's Vortec name, and Straight-4,

Straight-5 The straight-five engine (also referred to as an inline-five engine; abbreviated I5 or L5) is a piston engine with five cylinders mounted in a straight line along the crankshaft. Although less common than straight-four engines and straight-six eng ...

, and Straight-6 engines are all part of the same family, sharing the same manufacturing equipment, rods, pistons, valves, and other parts. They feature

coil-on-plug ignition A distributor is an enclosed rotating switch used in spark-ignition internal combustion engines that have mechanically timed ignition. The distributor's main function is to route high voltage current from the ignition coil to the spark plu ...

systems,

variable valve timing In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with var ...

on the

exhaust Exhaust, exhaustive, or exhaustion may refer to: Law *Exhaustion of intellectual property rights, limits to intellectual property rights in patent and copyright law ** Exhaustion doctrine, in patent law ** Exhaustion doctrine under U.S. law, in ...

side,

electronic throttle control Electronic throttle control (ETC) is an automobile technology which electronically "connects" the accelerator pedal to the throttle, replacing a mechanical linkage. A typical ETC system consists of three major components: (i) an accelerator ped ...

, and a special oil pan with a pass-through for the

half shaft An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearin ...

s in

four-wheel drive Four-wheel drive, also called 4×4 ("four by four") or 4WD, refers to a two-axled vehicle drivetrain capable of providing torque to all of its wheels simultaneously. It may be full-time or on-demand, and is typically linked via a transfer cas ...

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. The Atlas engines feature aluminum cylinder blocks and heads, with the cylinder bores featuring replaceable steel

cylinder liner In a reciprocating engine, the cylinder is the space in which a piston travels. The inner surface of the cylinder is formed from either a thin metallic liner (also called "sleeve") or a surface coating applied to the engine block. A piston is se ...

s. The Atlas program began in 1995 along with the planning for GM's next-generation mid-size

SUVs A sport utility vehicle (SUV) is a car classification that combines elements of road-going passenger cars with features from off-road vehicles, such as raised ground clearance and four-wheel drive. There is no commonly agreed-upon definitio ...

and pickup trucks. These vehicles were designed around the I6 engine. The I6 version was used in a Baja 1000 racing truck, winning its first race in a class that also included

V8 engine A V8 engine is an eight-cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration. The first V8 engine was produced by the French Antoinette company in 1904, developed and u ...

s. Another I6-powered truck won the truck class at the

Pikes Peak International Hillclimb The Pikes Peak International Hill Climb (PPIHC), also known as The Race to the Clouds, is an annual automobile hillclimb to the summit of Pikes Peak in Colorado, USA. The track measures and has over 156 turns, climbing from the sta ...

. The 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 Tonawanda (formally ''City of Tonawanda'') is a city in Erie County, New York, United States. The population was 15,130 at the 2010 census. It is at the northern edge of Erie County, south across the Erie Canal ( Tonawanda Creek) from North To ...

, near Buffalo.

LL8 (Vortec 4200)

The LL8 (or Vortec 4200), is a straight-6 gasoline engine produced from 2002 to 2009. It was the first Atlas engine, and was introduced in 2002 for the

, and

. The engine was also used in the

, and

. It displaces , with a bore and stroke. It has four valves per cylinder, utilizes dual-overhead cams (

DOHC An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion cha ...

) design, and features

on the exhaust cam, a first for GM inline engines. When introduced, this engine's power was at 6,000

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

and torque was at 3,600 rpm. 2003 saw a slight bump in power to , while torque was unchanged. For 2006, power was increased to at 6,000 rpm and torque to ) 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. The engine redline is 6,300 rpm. The LL8 was on the

Ward's 10 Best Engines 10 of the World's best engines is an annual list of the ten ''"''best''"'' automobile engines available in the U.S. market, that are selected by '' Ward's AutoWorld'' magazine. The list was started in 1994 for Model Year 1995, and has been drawn ev ...

list for 2002 through 2005 and was the basis for all the other Atlas engines. With the closure of the

Moraine, Ohio Moraine is a city in Montgomery County, Ohio, United States. Situated on the banks of the Great Miami River, Moraine is an inner suburb of Dayton, Ohio and a part of the Dayton metropolitan area. The population was 6,307 at the 2010 census. ...

, plant and the discontinuation of the

platform (Chevrolet TrailBlazer, GMC Envoy, etc.), production of the LL8 also ended. Applications: * 2002–2009

, ''Envoy XL'', and ''Envoy XUV'' * 2002–2009

and ''TrailBlazer EXT'' * 2002–2004

* 2004–2007

* 2003–2008

* 2005–2009

4.2i

L52 (Vortec 3500)

The L52 (also called Vortec 3500), is a

straight-5 The straight-five engine (also referred to as an inline-five engine; abbreviated I5 or L5) is a piston engine with five cylinders mounted in a straight line along the crankshaft. Although less common than straight-four engines and straight-six eng ...

engine produced from 2004 through 2006. It displaces , with a bore and stroke. Dynoed at the

flywheel A flywheel is a mechanical device which uses the conservation of angular momentum to store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, as ...

it produces at 5,600

and at 2,800 rpm. The engine redline is 6,300 rpm. Applications: * 2002 Bel Air concept * 2004–2006

Chevrolet Colorado The Chevrolet Colorado, and its counterpart, the GMC Canyon, are series of compact and later mid-sized pickup trucks marketed by American automaker General Motors. They were introduced in 2004 to replace the Chevrolet S-10 and GMC S-15/Sonoma co ...

and

GMC Canyon GMC may refer to: Government India * Gandhinagar Municipal Corporation, in Gujarat * Gobichettipalayam Municipal Corporation, in Tamil Nadu * Guntur Municipal Corporation, in Andhra Pradesh * Guwahati Municipal Corporation, in Assam * Gwalior M ...

* 2006 Isuzu i-350 * 2006

LLR (Vortec 3700)

The LLR (also called Vortec 3700), is a

engine with dual

balance shafts Balance shafts are used in piston engines to reduce vibration by cancelling out unbalanced dynamic forces. The counter balance shafts have eccentric weights and rotate in opposite direction to each other, which generates a net vertical force. ...

produced from 2007 through 2012. It displaces , courtesy of a larger bore while keeping the stroke. The LLR also corrected the head issue found in the ''L52''. It produces at 5,600

and at 4,600 rpm. The engine redline is 6,300 rpm. This five-cylinder engine achieves better fuel economy and performance than the six-cylinder, but with more power and torque than the four-cylinder. Applications: * 2007–2012

and

* 2007–2010

* 2007–2008

Isuzu i-370 The Chevrolet Colorado, and its counterpart, the GMC Canyon, are series of compact and later mid-sized pickup trucks marketed by American automaker General Motors. They were introduced in 2004 to replace the Chevrolet S-10 and GMC S-15/Sonoma co ...

LK5 (Vortec 2800)

The LK5 (also called the Vortec 2800) is a straight-4

engine produced between 2004 and 2006, with a bore and stroke. It produces at 5,600

and of torque at 2,800 rpm. The engine redline is 6,300 rpm. Applications: * 2004–2006

and

* 2004–2006

Isuzu i-280 The Chevrolet Colorado, and its counterpart, the GMC Canyon, are series of compact and later mid-sized pickup trucks marketed by American automaker General Motors. They were introduced in 2004 to replace the Chevrolet S-10 and GMC S-15/Sonoma co ...

LLV (Vortec 2900)

The LLV (also called Vortec 2900) is a straight-4

engine produced between 2007 and 2012, with a bore and a stroke. It replaced the LK5 and produced at 5,600

and of torque at 2,800 rpm. The engine redline is 6,300 rpm. Applications: * 2007–2012

and

* 2007–2009 Isuzu i-290

References

External links

{{DEFAULTSORT:Gm Atlas Engine

Atlas An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...

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