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General Motors 3.4L engine was a V6 engine manufactured from 1991 to 1997 for use in several General Motors vehicles, including the Pontiac Grand Prix, the Chevy Lumina and the Oldsmobile Cutlass Supreme. This engine has been the forerunner to the manufacture of the Cadillac Northstar 4.1L V8.
Exterior
With a block made of metal cast iron, this 6 cylinder engine has 3 cylinders on each side arranged in a V shape. The right bank cylinders (1, 3, 5) are on the cowl end of the engine section whilst the left bank cylinders (2, 4, 6,) are located on the front side of the car. The crankshaft, which is retained by bearing caps that are machined with the block for proper alignment and clearances, is held in place by four bearings. The aluminum cylinder heads have two intake and two exhaust valves for each cylinder. These heads contain pressed-in valve guides and valve seat inserts.
Cam Shaft
The aluminum camshaft carriers each contain one intake and one exhaust camshaft. The aluminium in the carrier serves as the camshaft bearing surface. The camshaft thrust plates, which control the camshaft location, are mounted on the rear of the carriers. The camshaft drive is a bi-stage system. Initially, it transfers power from the crankshaft to an intermediate shaft via a chain drive. The second stage uses a belt between the intermediate shaft and the individual camshafts. Both chain and belt tension is set and maintained by fully automatic tensioners. Timing must be reset if sprockets are removed from their shafts. Pins or keys are not used to establish camshaft to crankshaft timing in this engine.
Pistons
The GM3.4L engines pistons are aluminum with steel struts using double compression rings and one oil control ring. The piston pin is offset 0.7 mm (0.028 in) towards the dominant thrust side. This permits a gradual change in the thrust pressure on the cylinder wall as the piston moves in its path. Pins are chromium steel and have a floating fit in the pistons. They are kept in the connecting rods by a press fit. Connecting rods are made of forged steel. Full pressure oiling is channelled to the connecting rods by drilled oil routes from the adjacent main bearing journal.
Performance
This 3.4L V6 engine has a power rating of 200- 210hp (150kW-160kW) at 5,200 rpm. The torque of the engine is 292 Nm at 4,000 rpm. This engine drives the front wheels only.
