The LS9’s output is nearly 103 horses per litre, or just about 1.7 horses for each of the engine’s 376 cubic inches. It is unquestionably the most powerful automotive production engine ever manufactured by General Motors and enables the Corvette ZR1 to achieve a top speed of more than 200 mph (322 km/h).

"One of the most amazing things about the Corvette ZR1 is the level of refinement that our designers and engineers have attained. Even with all that power, this car has road manners that will allow our customers to enjoy it on the streets as a daily driver, and on the track," said Chevrolet General Manager Ed Peper.

The Corvette ZR1 goes on sale this (northern) summer. Its 638-hp supercharged engine is complemented in the chassis by heavy-duty components not offered in any other model, including a six-speed manual transmission with race-hardened gears and dual-disc clutch technology that delivers exceptional clamping power and lower inertia, as well as strengthened axle components.

Fuel economy testing has not been completed, but engineers are confident the ZR1 will be the most fuel-efficient 600-plus-horsepower car on the market.

The LS9 engine is hand-built by specially trained technicians at GM’s Performance Build Centre in Wixom, Michigan (USA). It is a unique, small-volume engine production facility that also builds the Chevrolet Corvette Z06’s LS7 engine and other high-performance GM production engines.

“Developing the LS9 involved more than simply striving for a great horsepower number. Endurance and reliability testing have shown the engine to be robust and low-maintenance, just like other engines in the small-block family,” said Sam Winegarden, executive director, engine engineering for GM Powertrain. “That it is distinguished as the most powerful engine ever from General Motors is a source of immense pride among everyone involved with the LS9.”

Supercharged aspiration

The key enabler of the LS9’s performance is the industry’s first production application of a new, positive-displacement Roots-type supercharger that has a unique four-lobe rotor design. Its design promotes quieter and more efficient performance, while the large, 2.3-litre displacement ensures adequate air volume at high rpm. Maximum boost pressure is 10.5 psi (0.72 bar). It is teamed with an integrated charge cooling system that reduces inlet air temperature for maximum performance.

“The combination of large displacement and the new, four-lobed rotor design broadens the effective range of the supercharger, allowing the engine to make more power at lower rpm and sustain it throughout the power band,” said Winegarden. “The low-end torque is tremendous and the high-rpm charge from the supercharger is simply amazing.”

A raised bonnet provides adequate clearance for the LS9, while a polycarbonate window in the bonnet provides a view of the engine beneath it.

LS9 details

The LS9 features many unique design and manufacturing details that support its high-performance nature. They include:

• Aluminum cylinder block with iron cylinder liners that are finish-bored and honed with a deck plate installed
• Forged steel crankshaft with a nine-bolt flange
• Titanium connecting rods and forged aluminium pistons
• Stronger, rotocast cylinder heads with 2.16-inch (55 mm) titanium intake valves and 1.59-inch (40.4 mm) hollow-stem, sodium-filled exhaust valves
• Camshaft with 0.555-inch (14.1 mm) lift for excellent idle and low-speed driving qualities
• A dry-sump oiling system with 10.5-quart (9.9 litres) capacity
• Integrated oil cooler and piston-cooling oil squirters
• Intercooler cover visible through the bonnet window that features ZR1-unique blue accents and “LS9 SUPERCHARGED” embossed on the left and right sides

About General Motors

General Motors Corporation, the world’s largest car maker, has been the annual global industry sales leader for 77 years. Founded in 1908, GM today employs about 266,000 people around the world. With global headquarters in Detroit (USA), GM manufactures its cars and trucks in 35 countries. In 2007, nearly 9.37 million GM cars and trucks were sold globally under the following brands: Buick, Cadillac, Chevrolet, GMC, GM Daewoo, Holden, HUMMER, Opel, Pontiac, Saab, Saturn, Vauxhall and Wuling. GM’s OnStar subsidiary is the industry leader in vehicle safety, security and information services.

Specifications