Piston and Connecting Rod Assemblies
The pistons are cast aluminum. The pistons use 2 compression rings and a 3-piece oil control ring assembly.
The piston is a low friction, lightweight design with a barrel shaped skirt. All applications use pistons with
graphite-coated skirts. The piston pins are chromium steel. First design applications use a piston pin that is
floating fit to the piston and press fit to the connecting rod. Second design applications use a pin that is full-
floating to both the piston and connecting rod. The connecting rods are powdered metal. The connecting rods
are fractured at the connecting rod journal and then machined for the proper clearance. The first design piston,
pin, and connecting rod are to be serviced as an assembly.
Valve Rocker Arm Cover Assemblies
The valve rocker arm covers are cast aluminum and use a pre-molded silicone gasket for sealing. Mounted to
each rocker cover is an ignition coil and bracket assembly. Incorporated into the right cover is the oil fill tube,
the positive crankcase ventilation (PCV) system passage, and the engine fresh air passage.
Valve Train
Motion is transmitted from the camshaft through the hydraulic roller valve lifters and tubular pushrods to the
roller type rocker arms. The valve lifter guides position and retain the valve lifters. The valve rocker arms for
each bank of cylinders are mounted on pedestals or pivot supports. Each rocker arm is retained on the pivot
support and cylinder head by a bolt. Valve lash is net build. For the LS6 application, both the intake and exhaust
valves are of a hollow stem design. The exhaust valve stem is sodium filled for improved cooling.
NEW PRODUCT INFORMATION
The purpose of New Product Information is to highlight or indicate important product changes from the
previous model year.
Changes may include one or more of the following items:
z
Torque values and/or fastener tightening strategies
z
Changed engine specifications
z
New sealants and/or adhesives
z
Disassembly and assembly procedure revisions
z
Engine mechanical diagnostic procedure revisions
z
New special tools required
z
A component comparison from the previous year
Torque Values and/or Fastener Tightening Strategies
z
All fasteners and threaded holes on the LS1/LS6 engines utilize metric threads.
z
Cylinder head, connecting rod, crankshaft balancer, and main bearing cap bolts now apply a torque angle
tightening strategy.
z
First design engine blocks cylinder head bolts have different torque/angle specifications using both
2004 Chevrolet Corvette
2004 ENGINE PERFORMANCE Engine Mechanical (Introduction) - 5.7L - Corvette
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