Chevrolet has now revealed almost everything about the new engine in its all-new 2014 Corvette. We know that the new small-block will be a 6.2-liter V-8 called LT1, with fuel-saving tricks like variable valve timing and cylinder deactivation But this is far from the first time that the Corvette has birthed innovations in General Motors’ small-block engine lineup. Here’s a brief look back at some of the headlining engine technologies that debuted on the Chevrolet Corvette.
4.3 liters (265 cu. in.)
When the Chevrolet Corvette debuted in 1953 it had one fatal flaw: a weak 150-hp “Blue Flame” inline-six engine that hampered performance sales. By 1955, GM engineers Ed Cole and others had come up with a solution in the form of Chevrolet’s new V-8 engine. It was lighter than the old inline-six and used a simpler, cheaper casting process than other V-8 engines in the GM stable. Best of all, the combination of V-8 power and a three-speed stick helped make the Corvette feel like a legitimate sports car, kick-starting sales. The engine’s 90-degree V-angle, 4.4-inch bore spacing, and pushrod valvetrain layout came to define the Chevrolet V-8 engine to this day. Despite all of the benefits to the V-8, reports show that at least seven customers still purchased a six-cylinder 1955 Corvette.
1957 — Fuel Injection
4.6 liters (283 cu. in.)
283 hp @ 6200 rpm, 290 lb-ft @ 4400 rpm
The first fuel-injected Corvette arrived in limited numbers for 1957. Its mechanical fuel-injection system, called Ramjet, used a high-pressure pump to deliver fuel into the intake plenum just before the cylinder head. This make for more accurate fuel metering that improved power and fuel economy, and also allowed for quicker throttle response than with carburetors. The engine delivered 250 hp when equipped with hydraulic lifters, and optionally made 283 hp if fitted with solid lifters. Power was increased to 290 hp by 1958 and to 315 hp for 1961. The system was relatively crude by today’s standards, but paved the way for fuel injection of all modern Corvettes.
1969 — Displacement grows to 350 cubic inches
5.7 liters (350 cu. in.)
The displacement of the Chevrolet small-block V-8 continued to grow through the 1960s until it reached 350 cubic inches, or 5.7 liters, in the 1969 Corvette. That was pretty much the feasible limit for displacement in the engine’s framework, and so the “350 V-8″ quickly became a fixture. In fact, the base Corvette engine would continue to displace 350 cubic inches until the C5 car debuted in 1997.More than half of all 1969 Corvettes were equipped with the new 350 V-8.
1985 — Electronic “Tuned-Port Injection”
5.7 liters (350 cu. in.)
230 hp @ 4000 rpm, 330 lb-ft @ 3200 rpm
For 1985, the Chevrolet Corvette gained a new engine dubbed L98 that boosted acceleration considerably. It used a new fueling setup called Tuned-Port Injection, which could be considered the Corvette’s first truly modern electronic fuel injection system. Whereas older electronic fuel-injection systems simply squirted fuel into the intake manifold after the throttle body, TPI had eight fuel injectors positioned directly in front of each of the engine’s intake valves. This led to another improvement in fuel metering accuracy, making the L98 more powerful and more fuel efficient than its predecessor, Chevrolet’s throttle-body injector system. By 1986, a switch to aluminum heads bumped power to 235 hp, and in 1987 Chevrolet installed roller rockers to bring power to 240 hp.
5.7 liters (350 cu. in.)
375 hp, 370 lb-ft
Some people don’t consider it a “true” small-block, but the LT5 engine in the 1990-1995 Chevrolet Corvette ZR-1 had the same 90-degree V-angle and 4.4-inch bore spacing as any other small-block V-8. The LT5 engine was a notable effort to modernize the Corvette’s engine and bring it toward the power output levels of exotic cars — a feat accomplished again with the likes of the modern-day Z06 and ZR1. Whereas even modern Corvette engines use a two-valve pushrod layout, the LT5 had a four-valve dual-overhead-cam setup that yielded much more power. The LT5 was an all-aluminum engine designed in partnership with Lotus, and built by Mercury Marine. So powerful was the resultant Corvette ZR-1 that it came with a special valet key that limited horsepower output for occasions when the car had to be loaned to less-skilled drivers. Output was 375 hp(compared to just 250 hp from the pushrod engines in regular 1990 Corvettes) and in later years the ZR-1 saw its ratings climb to 405 hp.
1992 — Gen II LT1 small-block
5.7 liters (350 cu. in.)
300 hp @ 4400 rpm, 340 hp @ 4000 rpm
The so-called Gen I small-block V-8 was getting old, so by 1992 the Corvette debuted with a wholly revised engine called the LT1. It met its design goal of producing 50 more horsepower than the outgoing L98, which was rated for 250 hp by 1991, and also proved more fuel efficient than the old small-block. Chief among the improvements were a new electronic ignition timing system called OptiSpark that measured crankshaft rotation to one-degree precision, a reverse-flow coolant setup that cooled the cylinder heads before the block, and a more compact design that allowed for a freer-flowing intake manifold with more precise port fuel injectors.
5.7 liters (347 cu. in.)
345 hp @ 5600 rpm, 350 lb-ft @ 4400 rpm
Chevrolet’s LS1 V-8 engine was so impressive that it earned Automobile Magazine‘s Technology of the Year award in 1998. A long list of innovations includes all-aluminum construction and Chevrolet’s first production drive-by-wire throttle and first composite intake manifold. By virtue of using aluminum, the new LS1 was nearly 90 pounds lighter than previous Corvette V-8 engines. After its debut in the Corvette, the LS1 was added to the 1998 Chevrolet Camaro Z28 (producing 305 hp) and the Camaro SS (with 320 hp). By 2001, some minor tweaks added five horsepower to all three models — 350 hp in the Corvette, 310 hp in the Camaro Z28, and 325 hp in the Camaro SS.
2007 — Z06 LS7 Engine
7.0 liters (427 cu. in.)
505 hp @ 6300 rpm, 470 lb-ft @ 4800 rpm
With a screaming 7000-rpm redline, the LS7 is Chevrolet’s highest-rated naturally aspirated production small-block V-8. It’s a special larger-displacement version of the V-8 engine in regular Corvettes, and is hand-built in Wixom, Michigan. High-performance tricks include titanium connecting rods, a titanium exhaust, and dry-sump oiling. To maximize the engine’s performance potential, the Corvette Z06 itself saves weight with an aluminum space frame and carbon-fiber door panels. Chevrolet says the Corvette Z06 can hit 60 mph in 3.7 seconds and a top speed of 198 mph. The size of the engine (427 cubic inches) matches up to big-block Corvettes from the 1960s, but the LS7 was indeed based on the framework for the small-block V-8.
Supercharged 6.2-liter (376 cu. in.)
638 hp @ 6500 rpm, 604 lb-ft @ 3800 rpm
Like the LS7 engine in the Z06, the Corvette ZR1′s engine is hand-built — but that’s about the only similarity. The 6.2-liter LS9 engine is supercharged to the tune of 638 hp, making it the most powerful production Chevrolet car engine in history. And the ZR1′s top speed of 205 mph makes it the fastest production Chevrolet of all time. It also has titanium connecting rods for extra strength, as well as special cast-iron cylinder liners to fortify the aluminum block.