How Much HP Does The LS4 V8 Have & Who Makes The Engine?

Many American carmakers are known for their engines. You have engines like the Ford Power Stroke, the Cummins diesel from Cummins, and General Motors' Duramax, all of which have made a name for themselves over the past two decades. However, there's also the LS family of engines, which, like the Duramax, is built by General Motors. 

The LS series has several generations of great motors to choose from, from the original LS1 and LS2 down to the LS9. Each of these engines had something unique to bring to the table. You might have heard someone talk about how well an LS engine performs in an engine swap, or how powerful the LS7 and LS9 are. You may also have heard them mention the LS4 V8, which, while not as potent as the rest of its siblings, still puts out a respectable 303 hp and 323 lb-ft of torque. The LS4 was also different from other LS engines, due to its mounting position and drive system. Let's talk about it.

General Motors introduced the LS series of engines in 1997. Eight years later, the LS4 would roll off the factory line, featuring predominantly in General Motors' front-wheel-drive vehicles, such as the Chevy Impala SS and Buick LaCrosse Super. The engine had a 325-cubic-inch (5.3-liter) displacement, with a bore of 3.780 inches and a stroke of 3.622 inches, along with a compression ratio of 10:1. 

A small-block, like its siblings, the LS4's block, cylinder heads, and intake manifold were made of aluminum, with a cast-iron crankshaft and flat-top hypereutectic cast-aluminum alloy pistons. General Motors mounted it in a transverse position, with the engine's starter mounted on the transmission instead of the engine block. Since the motor featured in the company's front-wheel-drive vehicles, its crankshaft and accessory drive all fit in the engine bay, giving the engine a configuration that made it stand out from GM's other LS engines.

The LS4 was offered between 2005 and 2009. A total of four vehicles came equipped with the engine, spread across the four years. The Pontiac Grand Prix GXP was the first to feature the engine in 2005, and General Motors offered the vehicle up to 2008. Alongside it were the Chevrolet Monte Carlo SS and Chevrolet Impala SS, both of which debuted in 2006. However, while the Monte Carlo SS featured the engine up to 2007, the Impala SS had it for two more years. General Motors also offered the LS4 engine in the Buick LaCrosse Super, which featured the motor between 2008 and 2009. 

The LS4 will always be an interesting engine, even though it's been over a decade since General Motors produced it. It was lightweight and compact, which meant it took up less space and reduced weight over the front wheels. If you're interested in getting your hands on one, your best bet is probably sourcing used engines from specialist retailers.