Engine: Description and Operation
GENERAL INFORMATION
The 8.0 Liter (488 CID) ten cylinder engine is a 900 V-Type, lightweight, single cam, overhead valve engine. The cylinder block and cylinder heads are aluminum. The crankshaft is forged steel. This engine is designed for unleaded premium fuel. The cylinders are numbered from front to rear; 1, 3, 5, 7, 9 on the left bank and 2, 4, 6, 8, 10 on the right bank. The firing order is 1, 10, 9, 4, 3, 6, 5, 8, 7, 2.
CYLINDER BLOCK: The cylinder block is sand cast aluminum alloy with separate cast iron liners. These liners are slip fit into the block with 2 0-ring seals at the base of water jacket for coolant and oil sealing. The 6 Main Bearing Caps use Four bolts per cap. A windage tray is attached to the main caps via extended main cap bolts. The block and heads incorporate a unique parallel coolant flow.
CYLINDER HEADS: Cylinder heads are sand cast aluminum incorporating dual quench combustion chambers. Valve guides are hardenable iron inserts and valve seats are powder metal inserts, press fit into the cylinder head. A steel flanged silicone beaded composition type gasket is used between head and block. High turbulence cylinder heads allow a 9.1:1 compression ratio.
CRANKSHAFT: The forged steel crankshaft is supported by the six main bearing caps. The No.3 bearing is the thrust bearing. Crankshaft end sealing is provided by front seal and a rear seal. The crank-shaft rotation is clockwise, when viewed from the front of the engine. The #5 counterweight has integral circular disk with 10 notches for DIS pickup.
PISTONS: The pistons are forged aluminum. Three rings are used. Piston pins (press fit into the rods) join the pistons to forged steel shot peened connecting rods.
CAMSHAFT: The nodular iron camshaft is supported by six journals directly in the aluminum block. A thrust plate located in front of the first bearing, and bolted to the block, controls end play. A dual roller chain is used to drive the camshaft. The chain is enclosed by a cast aluminum cover. This cover holds the oil pump, the front crankshaft seal, provides front oil pan closure, oil filter and water pump mounting.
VALVE COVERS: The valve covers are die cast magnesium sealed with plastic backed silicone gaskets.
INTAKE MANIFOLD: The intake manifold is a one piece brazed assembly of cast aluminum and formed aluminum tubing. It incorporates cast-in fuel rails for the bottom feed fuel injectors. There is pro-vision for Automatic Idle Speed (MS) Motor mounting at the rear of the right plenum. The dual log runners design is tuned for high speed Dual throttle bodies are mounted to the front of the intake plenums. Sealing of the intake manifold to the heads by using fiber gaskets with molded-on silicone beads.
VALVE TRAIN: Valve train has hydraulic roller lifters. Rocker arms are common either right or left, and installed on individual rocker arm pedestals attached to the cylinder head. Piston valve stem seals provide positive intake and exhaust valve sealing. Conventional type hollow push rods, retainers and valve stem locks are used. The relative high engine speed and high lift cam require dual valve springs. Valve spring seats are used to protect the aluminum cylinder heads and guides.
EXHAUST MANIFOLDS: Exhaust manifolds are cast thin wall, HiSilMoly iron, one piece design with large runners. The lower section has a heated oxygen sensor on each side. A graphoil gasket must be used between the exhaust manifold and aluminum cylinder head.