LS3 V8 makes up to 436bhp
GM has unveiled the 2008 model year Corvette and the good news is that it’s got even more grunt. The new LS3 6.2 litre V8 thumps out 430bhp and 424lb ft of torque (the previous 6.0 litre motor made 400 units of each) and if you specify the new two-mode exhaust not only do you get more noise under hard acceleration, you get higher outputs: 436bhp and 428lb ft of torque to be precise.
The manual transmission has been revised to offer a more direct and positive feel with better gate to gate location, and the paddle shift automatic has new hardware and revised calibration. Revised steering to help improve feel and new wheels are also amongst the changes, as are two new exterior colours and a revised instrument panel.
For those of you feeling the need for some V8 appreciation this morning, we’ve copied the engine section of the GM press release and pasted below for you to enjoy. Deep breath, and:
This new iteration of the storied small-block family features a revised, larger-bore cylinder block – 4.06-inch / 103.25 mm vs. the previous 6.0L’s 4.00-inch / 101.62 mm bores – high-flow, LS7/L92-style cylinder heads; larger-diameter pistons; revised camshaft and camshaft timing; revised valve train with offset intake rocker arms; high-flow intake manifold; high-flow fuel injectors from the Z06’s LS7 engine; and a new engine beauty cover.
The LS3 features an aluminium cylinder block with cast iron cylinder liners. In addition to its larger bores, which help create a 376-cubic-inch displacement, the block casting also features revisions and machining in the bulkheads that enhance its strength and improved bay to bay breathing. But while the bore of the 6.2L engine is increased when compared with the previous 6.0L engine, the engine’s stroke remains at 3.62 inches (92 mm). The pistons for the larger 6.2L engine also are new and are designed for its high-rpm performance capability.
Breathing for the new 6.2L engine is accomplished via new, high-flow cylinder heads. They’re based on the large port/large valve design found on the LS7 engine and other GM L92 engines, with larger-capacity, straighter intake ports. The design optimizes intake flow to the combustion chamber and the exhaust ports are also designed for better flow.
Complementing the larger-port design of the heads are commensurately sized valves. The intake valve size alone increases from 2.00 inches (50.8 mm) to 2.16 inches (55 mm) – an increase of nearly 9 percent. The intake valves feature lightweight hollow stems, which enable the engine’s 6,600-rpm capability. The exhaust valves also are large, measuring 1.60 inches (40.4 mm) in diameter.
To accommodate the engine’s large valves and enable more direct intake port flow, the intake-side rocker arms are offset 6 mm between the valve tip and the push rod. Actuating the valves is a new camshaft, with intake-side lobes providing more than a 5-percent percent in increase in lift, from 0.521-inch to 0.551-inch (13.25 mm to 14 mm). Exhaust-valve lift remains unchanged from the LS2. The camshaft timing was revised to optimize performance with the higher-lift intake cam profile.
Ensuring the cylinder heads receive all the air they can handles falls to a new, acoustically tuned intake manifold. The composite design is manufactured with a “lost core” process that improves runner to runner variation and reduces airflow losses. An acoustic foam material is used to reduce radiated engine noise; it is sandwiched between the outer top of the manifold and an additional “skull cap” acoustic shell. Also new beauty covers atop the engine shield the rocker covers and also feature a noise-reducing, acoustically tuned insert to provide a more refined engine sound.
Exhaust system – Optional on ’08 Coupe and Convertible models is a new, two-mode performance exhaust system. Similar in design and function to the system used on the Z06, the dual-mode exhaust uses vacuum-actuated outlet valves, which control engine noise during low-load operation, but open for maximum performance during high-load operation. It is not identical to the Z06 system; the Coupe/Convertible uses a 2.5-inch-diameter exhaust, while the Z06 uses a three-inch system.