The seventh-generation 2014 Chevrolet Corvette will produce at least 450 hp and 450 lb-ft of torque from an all-new small-block V-8 engine. The fifth-generation of GM’s iconic eight-cylinder, known as the LT1, displaces 6.2 liters and adopts direct injection, cylinder deactivation, and continuously variable valve timing in the pursuit of greater performance and efficiency. Chevrolet is targeting a 0-60-mph time of less than four seconds and a 26-mpg highway fuel economy rating for the 2014 C7 Corvette.
“Our customers' own fears were, coming out of bankruptcy, with the pressures of [Corporate Average Fuel Economy], were that the Corvette would be a shadow of itself,” said Corvette chief engineer Tadge Juechter. “We’re not going to be a shadow.” He acknowledges that his Corvette team investigated alternative engines such as the long-rumored turbocharged V-6, but contends that the small-block was better qualified to meet performance standards, efficiency expectations, and customer demand. The V-8 engine is still kicking. “I’m not going to say we’ll [build] 100 million more. But we’re going to do millions more,” Juechter said.
The LT1 represents a new chapter in the small-block’s 57-year history, with GM claiming the engine is 99.9% new. During a presentation to journalists, small-block engine chief engineer Jordan Lee held up a sandwich bag of carryover parts. Its contents: two starter bolts, a piston pin, and a few miscellaneous bits. At the same time, the 466-pound engine preserves some small-block hallmarks. The LT1 retains 4.4-inch bore spacing and a camshaft mounted in the block with pushrod-actuated valves. Overhead camshafts would have added four inches to the small-block’s 25.3-inch height, requiring that the C7 Corvette’s hoodline be raised.
While the Corvette team was unwilling to compromise on the hood height, they have raised the compression ratio to 11.5:1. The LT1 is also likely the first overhead-valve engine with direct injection, with injectors located deep in the engine’s vee. They are fed by a cam-driven fuel pump. The variable valve timing, while new to the Corvette, isn’t as sophisticated as most overhead-cam arrangements. The small-block can shift the valve events by up to 62 degrees, but can’t adjust intake and exhaust valve timing independently. Valve timing is advanced for more torque and retarded for better fuel economy.
Cylinder deactivation allows the engine to operate as a 3.1-liter V-4 using cylinders 8, 2, 5, and 3, with a claimed 20 percent efficiency improvement when the system (called Active Fuel Management) is active. Engineers promise that the engine note will measure up to expectations in all conditions. “We’re looking forward to another generation of ground-pounding American thunder,” Juechter said.
For now, GM is silent on future performance derivations that could power a new Z06 or ZR1. They have revealed that a dry-sump oil system will be available on the LT1, hinting at a future for the Corvette Grand Sport coupe. That model currently uses the base Corvette’s LS3 engine with a dry-sump system.
The LT1 will be assembled at GM’s Tonawanda engine plant in New York, which opened in 1937 and played a role in building the original 1955 small-block V-8.
The 2014 C7 Chevrolet Corvette will be unveiled on January 13, 2013, in conjunction with the Detroit auto show.
2014 Chevrolet Corvette LT1 V-8 Specifications
Engine type: 90-degree V-8 with overhead valves; continuous VVT
Displacement: 6.2L (376 cubic inches)
Bore x Stroke (in / mm): 4.06 x 3.62 / 103.25 x 92
Cylinder block: cast aluminum with nodular main caps
Main bearing fasteners: six, including two cross-bolts per cap
Crankshaft: forged steel
Connecting rods: powder metal, 6.125 inches in length
Pistons: eutectic aluminum alloy
Compression ratio: 11.5:1
Cylinder heads: 319-T7 cast aluminum with 59.02cc combustion chambers
Valve angles (degrees): 12.5 intake, 12 exhaust
Intake valves: 2.13 inches (54mm) hollow
Exhaust valves: 1.59 inches (40.4mm) hollow sodium
Camshaft: Hydraulic-type with tri-lobe for fuel-pump drive
Camshaft lift: 0.551-inch (14mm) intake / 0.524-inch (13.3mm) exhaust
Camshaft duration: 200-degrees intake / 207-degrees exhaust (at 0.050-inch)
Lobe separation angle: 116.5 degrees
Fuel delivery: direct injection
Intake manifold: “runners in a box” design; composite construction
Throttle: 87mm electronically controlled throttle body
Ignition: 58X with individual coil-on-plug and iridium-tip spark plugs
Horsepower: 450 hp @ 6000 rpm (estimated)
Torque: 450 lb-ft @ 4000 rpm (estimated)
Max. engine speed 6,600 rpm (fuel cutoff)