5.7L LS1 V8 When current Corvette owners are asked what they'd most like to see in future Corvettes they inevitably say, "more power." So, 2001 Corvette coupe and convertible models with the standard LS1 engine got a healthy injection of just that.

Horsepower is increased from 345 @ 5,600 rpm to 350 @ 5,600 rpm. Torque increases from 350 lb-ft @ 4,400 rpm to 360 lb-ft @ 4,400 rpm. (375 lb-ft for manuals)

Corvette engineers designed a new composite intake manifold with increased plenum volume and smoother-flowing intake runners. This increased volume of air, delivered to the combustion chamber with less turbulence, allows camshaft lift and overlap to be moderated. The result of the greater air volume is an immediate five-horsepower increase, and the modifications to the camshaft broaden the torque curve yielding a big boost in torque at the low end.

5.7L LS6 V8
At the heart of the new Z06 is an engine that delivers almost 12-percent more horsepower than the 2000 LS1. Called the LS6, it shares many components with the LS1, and would look the same externally were it not for its red engine covers.

The LS6 produces 385 hp @ 6,000 rpm, and torque of 385 lb-ft @ 4,800 rpm. The engine is redlined at 6,500 rpm (versus the LS1's 6,000 rpm redline), and its torque curve is slightly biased toward the upper end where that power will be most appreciated on the track.

LS6 power output is achieved as the result of dozens of refinements to increase volumetric efficiency and maximum rpm. The most important of these refinements are detailed below:

Improved Bay-to-Bay Breathing
The aluminum block casting on the LS6 deletes machined holes in the LS1 bulkhead and adds cast in "windows" which allow better bay-to-bay breathing. On the down stroke, the pistons push air back toward the crankcase, creating backpressure or resistance, and that translates into parasitic horsepower loss because it resists piston motion. With the over travel windows air is allowed to move more freely between crankcase bays thus relieving the unwanted pressure.

New Pistons
LS6 pistons are cast from high-strength M142 aluminum alloy and reshaped with a slightly different profile than those in the LS1. In side view, the LS6 pistons have a slight barrel shape, almost imperceptible to the naked eye. The new alloy increases engine durability at racetrack operating levels, while the shape reduces internal mechanical noise.

Increased Compression
The LS6's aluminum cylinder heads are cast with smaller pent-roof combustion chambers than the LS1. Compression ratio increases from 10.1:1 to 10.5:1, improving thermal efficiency and increasing horsepower. Intake and exhaust ports in the LS6 head are refined and more-precisely cast, contributing to the engine's overall increase in volumetric efficiency.

New High-Profile Camshaft
The LS6-specific, steel-billet camshaft contributes more than any single piece of hardware to the LS6's horsepower gain. In simple terms, the cam opens the valves quicker and allows more air to flow into the combustion chambers. Cam lift increases from the LS1's 12.7 to 13.3 mm.

Stronger Valve Springs
To accommodate valve operation with the high lift/high duration cam, the LS6's valve springs are stiffer and sturdier. They are made from the same steel wire as those in the LS1 but are wound tighter for a higher spring rate.

New Injectors
Additional air flowing into the LS6 heads would serve no purpose without an equivalent increase in the amount of fuel to take advantage of it. New injectors increase maximum fuel delivery from the LS1's 3.3 grams/sec to 3.6 grams/sec - a 10 percent improvement.

New Integral PCV System
The LS6's application on the Corvette Z06 creates additional demands on the crankcase ventilation system. The Z06 is capable of cornering at more than 1 lateral "g" requiring a special high-performance ventilation system.

To prepare the Z06 for full-on driving, the LS6's PCV system is moved into the engine's V, or valley. The unique aluminum valley cover has composite oil separating baffles and PCV plumbing incorporated. All of this reduces oil consumption during high-performance driving - and as an added benefit also reduces the amount of external plumbing, eliminating potential oil leak sources.

New Thin-Wall Cast Iron Exhaust Manifolds
Thin-wall cast iron exhaust manifolds replace the previous stainless steel manifolds to improve durability - especially on the LS6 engine given its potential for being involved in sustained high-speed driving.