The New LS7

The most significant Corvette engine since the first small-block?

General Motors Mar 18, 2005 0 Comment(s)

Build It Better

The LS7 is not a product of a standard mass-productionassembly line, but rather is created at the new GM Performance BuildCenter, where each engine is hand-assembled by an engine-buildingtechnician specialist. The facility is dedicated to crafting engines forspecialty applications such as the Z06 in an environment akin to customrace-engine assembly. Each engine is viewed as an individual unit, andeach is seen through the assembly process as the responsibility of adedicated builder.

The engines are rigorously inspected and hot-testedin a 20-minute run cycle upon completion. Timothy Schag, site manager ofthe Performance Build Center, explains, "This process brings a higherlevel of quality because each builder is personally involved in everyaspect of the assembly. It was important to step away from thehigh-volume world we all had lived in for so long and soak in thecadence of these specialized environments. We learned a lot andestablished a low-volume manufacturing system on par with the world'sbest niche builders, but we didn't lose sight of the quality already inplace at GM."

We haven't failed to recognize the GM team's achievementin making this new small-block a milestone in the performance world.While we appreciate the engineering execution, it leaves us eager forthe thrill of shaking down the new Z06 in the flesh. Indications are of0-60 performance in the 3s, and quarter-mile acceleration in the 11s.Missile-like acceleration on that level would be recommendation enoughto indulge our own automotive requirements. However, acceleration andspeed alone are only one dimension of the capabilities of this best-yetCorvette platform. We're anxiously awaiting a set of keys to experienceit firsthand.

Camshaft Specs

Rocker-ratio intake: 1.80:1

Rocker-ratio exhaust: 1.80:1

Degrees Duration:

At camshaft: Intake: 0.331 in. Exhaust: 0.328 in.

At valve: Intake: 0.593 in. Exhaust: 0.588 in.

LS7 General Specs

Engine type: Cam-in-block 90-degree V-8Block configuration: Cast-aluminum with pressed-in cylinder sleeves and 6-bolt, forged-steel main bearing caps

Bore x Stroke (mm/in): 104.8x01.6/4.125x4.00

Displacement: 7.0L/427ci

Crankshaft: Forged steel

Connecting Rods: Forged titanium

Pistons: Cast aluminum

Compression Ratio: 11.0:1

Cylinder Heads: CNC-ported aluminum; 70cc chamber volume

Valve size, intake (mm/in): 56/2.20 (titanium)

Valve size, exhaust (mm/in): 41/1.61 (sodium-filled)

Camshaft: Hydraulic roller; 15 mm (.591 in) lift (intake and exhaust)

Rocker arms: 1.8:1; offset (intake only)

Air intake: Composite manifold with 90mm single-bore throttle body

Fuel: Premium required; 91-octane minimum

Horsepower: 500 (373 kW) @ 6,200 rpm

Torque (lb-ft): 475 (644 Nm) @ 4,800 rpm

Engine redline (rpm): 7,000


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