The LS1 engine is a third-generation small-block V8 produced by General Motors. Small-block V8s have been produced by GM since 1955, but the LS1, unlike the second generation LT1, bears little resemblance to the original powerplant other than size. The LS1, which can feature an all-aluminum or cast-iron block, are most notably found in the Chevrolet Corvette and Camaro, and the Pontiac Firebird.
The Generation II small-block LT series V8 replaced the original GM small-block in 1992. The LS1 replaced the LT series engines in 1997. The LS1 engines were produced through 2007. The Generation IV LS engine, which includes the LS6, was launched in 2005 and eventually replaced the Generation III LS versions by 2007.
The most prominent feature of the LS1 is the reverse cooling system developed by NASCAR to cool the heads first before the engine block to keep the head temperatures low and to avoid pre-ignition. It also is equipped with a stiff oil pan to maintain the structural integrity and rigidity of the block. The all-aluminum block is used in the Corvette and other high-performance GM cars. A cast-iron version is found in Chevrolet and GMC pickup trucks. Its 10.25:1 compression ratio allows the engine deliver maximum power output in a compact block. A hollow steel camshaft reduces engine's vibration and noise. Fuel is delivered through a sequential fuel injection system, according to Camarotech.com.
The LS1 displaces 5.665 liters (345.69 cubic inches). Its bore is 3.898 inches and the stroke measures 3.622 inches. The bore is slightly smaller than the 4-inch bore on the 400-horsepower 6-liter LS2 V8. But its overall dimensions are virtually the same as the original GM small-block and the Generation II. It features six-bolt main bearing caps.
The horsepower and torque output depend on the make, model and model year of the vehicle. Horsepower after 2000 has been rated at 350 with 365 foot-pounds of torque, the twisting force generated in the engine to allow the vehicle to carry a heavy load and give it acceleration. The 1997 through 2000 Corvettes were equipped with an LS1 V8 generating 345 horsepower and 350 foot-pounds of torque. Non-performance cars equipped with the cast-iron block provide between 305 and 315 horsepower. GM Holden, a subsidiary of General Motors, produced LS1 engines in Australia with horsepower ratings up to 402.
A 1997 to 2000 Corvette equipped with a 345-horsepower LS1 engine could hit 0-60 mph in just under 5 seconds with a top speed of 175. A 2001 Chevrolet Camaro Z28 equipped with a 310-horse LS1 achieved 0-60 mph in 5.5 seconds and the quarter mile in 14 seconds at 101.3 mph. The 2001 Camaro Super Sport equipped with the 320-horsepower version performed slightly better by clocking 0-60 mph testing in 5.3 seconds and the quarter mile in 13.7 seconds at 105.6 mph.
