Chevrolet Corvette C5 Z06 - LS6 Engine

LS6 Engine

The Z06 uses a high-output version of the LS1 small-block engine. The name was changed to LS6 after substantial modifications. The new engine powerplant produces about 12% more power than the LS1 and looks identical in external appearance save for the red engine covers. The LS6 produces 405 horsepower (302 kW) at 6000 rpm, and 400 lb·ft (542 N·m) at 4800 rpm. The engine redlines at 6500 rpm (versus the LS1's 6000 rpm redline).

The LS6 utilizes an aluminum block which has been modified to allow greater bay-to-bay breathing. Typically the LS1 engine allows too much air in its crankcase developing into parasitic loss of power. The LS6 relieves this unwanted pressure translating into a removal of parasitic loss thus gaining more power.

• New Pistons

The LS6 utilizes modified versions of the LS1 pistons. The new pistons are made from M142 aluminum alloy which has proved to be stronger and more durable than the material used in the LS1. The pistons have been reshaped to have a slight barrel shape difficult to see for the normal onlooker. The new design also reduces internal mechanical noise because of its increased efficiency.

• Increased Compression

The LS6 cylinder heads have been cast with pent-roof combustion chambers. This modification of the LS1 has decreased the cylinder size thus promoting a greater Compression ratio; from 10.1:1 to 10.5:1. The LS6 ports have been cast using tighter tolerances which has resulted in increased power, thermal efficiency, and increased volumetric efficiency.

• High-Profile Camshaft

The LS6 utilizes a camshaft constructed from steel billet materials. The timing of the camshaft has been altered by increasing the lift from those of the LS1 to provide quicker opening times. To accommodate higher lift and longer duration of the camshaft the valve springs have been manufactured to become stiffer. The springs are wound tighter than those in the LS1 which results in stronger springs able to handle the increased strain from the camshaft. These modifications result in more efficient air-flow into the combustion chambers and thus an increase in power.

• Fuel Injectors

The LS6 utilizes new and larger fuel injectors. The new injectors deliver 3.6 grams of fuel per second, an increase of 10% above the LS1. The injectors were designed to deliver more fuel as a result of the increase in air flow from the increased compression and camshaft opening duration modifications. The fuel to air mixture ratio needs to remain proportional to achieve operational status.

• Internal PCV System

The LS6 utilizes a newly designed Positive Crankcase Ventilation valve. The new PCV valve now rests in the "V" of the engine. The "V" aluminum cover contains composite oil separating baffles with unique tubing. This results in less overall oil tubing thus reducing the potentiality of oil leak sources. The presence of the oil baffles also reduces oil consumption and increases the performance capabilities of the ventilation system during high-performance maneuvers (greater than 0.55 lateral G) which the Z06 is capable of.

• Exhaust Manifolds

The LS6 utilizes newly designed exhaust manifolds. These manifolds are constructed of cast-iron material and have been designed to reduce weight by utilizing thin walls.