GM L33 Engine Specsby Anne Davis
The L33 is essentially an LM7, the most common variety of GM's 5.3-liter engines, with an aluminum block. It was available only in extended-cab, four-wheel-drive pickup trucks.
Bore and Stroke
In 2007 the L33 had a bore of 3.78 inches and a stroke of 3.62 inches. An engine's bore is the diameter of its cylinders, and its stroke is the distance its pistons travel inside the cylinder. Because displacement refers to the total amount of air displaced by the pistons inside the cylinders, the larger the bore and stroke, the larger and more powerful the engine can be.
With a compression ratio of 9.9:1 in 2007, this engine could produce 315 horsepower at 5,200 rpm and 338 foot-pounds of torque at 4,400 rpm. Such a high compression ratio indicates the engine's ability to produce more work, or torque; horsepower is a rate-based measurement of how quickly the engine can perform that work.
The L33 was available only in the four-wheel drive, extended-cab versions of vehicles like the Chevrolet Silverado and GMC Sierra from 2005 until 2007. In 2005, the first year of the L33's production, only about a quarter of GM's trucks featured this engine.