General Motors began developing its Gen-III Small-Block engine to replace its popular Gen-II V8 in the early 1990s. Chevrolet debuted the new 5.7-liter V8 engine, designated with engine code LS1, in the all-new C5 Corvette in 1997.
The LS1 featured an aluminum block and cylinder heads with steel or cast iron inserts for high-wear areas like valve guides and cylinder walls. Besides the reduced weight, the firing order was the most significant difference between the LS1 and its predecessor. The LS1 fires its cylinders in a 1-8-7-2-6-5-4-3 order, whereas the Gen-II V8 uses the 1-8-4-3-6-5-7-2 firing order.
The LS lineup’s horsepower values range from 345 in the 1997 5.7-liter LS1 Corvette to 638 in the 6.2-liter LS9-powered ZR1 Corvettes produced from 2009 to 2013. The ZR1 LS9 engine benefits from lightweight titanium connecting rods and a “2.3L Roots-style supercharger.” It also has 0.5 liters more displacement than the original LS1’s 5.7 liters.
