General Motors Atlas engine

Atlas is the name of a family of inline piston engines that General Motors built for its trucks, used in the GMT355 and GMT360 platforms. It debuted in 2002 with the Oldsmobile Bravada and went into the Buick Rainier, the Chevrolet TrailBlazer and Colorado, the GMC Envoy and Canyon, the Hummer H3, the Isuzu Ascender and the Saab 9-7X. Straight-four, straight-five and straight-six versions use the Vortec name and share manufacturing equipment, rods, pistons and valves; all have aluminum blocks and heads with replaceable steel cylinder liners, coil-on-plug ignition, electronic throttle control and variable valve timing on the exhaust cam, which let them meet emissions rules without exhaust gas recirculation. The first and best known, the LL8 Vortec 4200 straight-six of 2002 to 2009, made 270 horsepower and was on the Ward's 10 Best Engines list for four years. The program began in 1995, and the engines were built in Flint, Michigan, and Tonawanda, New York.