Engine Component Description. Buick GL7 (Export) 2000

For 1990-2009 cars

The cylinder block is made of cast alloy iron and has six cylinders arranged in a V shape with three cylinders in each bank. The cylinder banks are set at a 60 degree angle from each other.

The right bank cylinders are 1,3,5 and the left bank cylinders are 2,4,6 starting from the front of the engine.

Four main bearings support the crankshaft which is retained by bearing caps that are machined with the block for proper alignment and clearances. The main bearing caps are also drilled and tapped for the structural oil pan side bolts.

The aluminum cylinder heads have individual intake and exhaust ports for each cylinder. Valve guides and valve seats are pressed in, and roller rocker arms are located on a pedestal in a slot in the cylinder head and are retained on individual threaded bolts.

The crankshaft is cast nodular iron with deep rolled fillets on all six crankpins and all four main journals. Four steel-backed aluminum bearings are used, with the #3 bearing being the end-thrust bearing.

The camshaft is made from a new metal composite design. The camshaft profile is a hydraulic roller design. The camshaft is supported by four journals and includes an oil pump drive gear.

The pistons are cast aluminum using two low tension compression rings and one oil control ring. The piston pin is offset 0.8 mm (0.031 in) towards the major thrust side. This allows a gradual change in thrust pressure against the cylinder wall as the piston travels its path. Pins are chromium steel and have a floating fit in the pistons. They are retained in the connecting rods by a press fit.

Connecting rods are made of forged steel. Full pressure lubrication is directed to the connecting rods by drilled oil passages from the adjacent main bearing journal.

A roller rocker type valve train is used. Motion is transmitted from the camshaft through the hydraulic roller lifter and the pushrod to the roller rocker arm. The rocker arm pivots on needle roller bearings and transmits the camshaft motion to the valve. The rocker arm pedestal locates in a slot in the cylinder head and the rocker arm is retained in the cylinder head by a bolt. The pushrod is located by the rocker arm.

The intake manifold is a two-piece cast aluminum unit. It centrally supports a fuel rail with six fuel injectors.

The exhaust manifolds are cast nodular iron.