2007 LY6 Engine Specificationsby Dennis Hartman
The LY6 engine is an internal combustion gasoline engine built by American automaker General Motors. GM began producing the LY6 in 2007 as a new entry into its Vortec engine line. Since then GM has continued to offer the LY6 in some versions of its Chevrolet and GMC trucks.
The LY6 also goes by the name Vortec 6000, which refers to its 6.0-liter, or 6,000 cubic-centimeter displacement. In reality the LY6 has a displacement of 5,967 cubic inches, which is equivalent to 364 cubic inches.
The LY6's displacement qualifies it as a small-block engine. It uses a V8 configuration. The LY6 has an overhead valve layout with just one exhaust valve and one intake valve per cylinder, for a total of 16 valves. Hydraulic rollers lift the valves, which open to allow the cylinders to fire in a 1,8,7,2,6,5,4,3 sequence. The LY6 has a cast iron block and cast aluminum cylinder head, as well as a hollow steel camshaft and a nodular iron exhaust manifold.
The LY6 has a compression ratio of 9.6:1. Its bore and stroke measure 4.0 inches by 3.62 inches, respectively. The engine uses sequential fuel injection and drivers can use regular unleaded gasoline as fuel. The LY6 has a fuel shut-off feature that engages at 6,000 revolutions per minute (rpm).
GM included the LY6 engine in several different vehicles for the 2007 model year. These include the Chevrolet Silverado HD pickup truck, the GMC Sierra full-size pickup and the three-quarter ton versions of the full-size GMC Yukon XL and Chevrolet Suburban SUVs. In some cases the LY6 was just one of several options in each of these vehicles, with smaller and larger Vortec engines, as well as hybrid and diesel variants, also available.
For each application the LY6 engine achieves slightly different power output. For example, in the 2007 Silverado Work Truck, the LY6 produces up to 353 horsepower at 5,400 rpm and 373 foot-pounds of torque at 4,400 rpm, while the same engine makes 352 horsepower and 383 foot-pounds of torque at similar engine rpm in the GMC Yukon XL.