Today, V8s are reserved for use in full-sized 4x4s where buyers are willing to pay for the additional horsepower and torque. Jeep's V8 hardware has been consolidated into the 5.9-litre (360-cubic-inch) engine, which offers an optimum V8 mix of power and economy.

Evolved from the original AMC 290-cubic-inch V8, the 360 is closely related to Jeep's former 304 V8 by virtue of a 0.33-inch bore increase from 3.75 to 4.08 inches. Generous bore-to-bore spacing keeps heat transfer from one combustion chamber to the next at a minimum. The stroke remains at 3.44 inches.

The block is a lightweight design with the skirts stopping at the crank centreline. In the bottom, a cast nodular iron crank rides on five main bearings, with the number three bearing acting as thrust bearing. Two-bolt main caps keep the crank spinning on course.

Above the crank is the cast iron cam supported by five bearings. The hydraulic lifters operate the pushrod-controlled valves. Valve components consist of stamped rocker arms riding on a sintered iron pivot, which are located with a stamped steel bridge. Retaining bolts bind the assemblies to the threaded head pedestal.

One reason why the 5.9 V8 is capable of producing so much torque can be traced to its cam timing. With 263.5 degrees duration, for intake and exhaust, there's plenty of time for the cylinder to fill up with air/fuel mixture. The engine breathes through a two-barrel carb mounted on a cast iron, dual-plane intake manifold. Spark from the coil goes through the tilted, front-mounted electronic distributor.

As with the six-cylinder pistons, the V8 has two compression rings and one oil-control ring. The pistons are cast aluminium alloy, with a slipper skirt design. They're offset .0625 inch toward the major thrust side for quiet operation, and generate 8.25:1 compression ratio. Connecting the pistons and cast iron rods are steel piston pins pressed by 2000 pounds of pressure. Press-fit eliminates the use of external pin retainers.

On top, the cast iron heads cover a wedge-style combustion chamber with a head chamber volume of 58-61 cubic centimetres to induce turbulence for maximum combustion. Exhaust exits via cast iron manifolds that employ banjo-style fittings for the air-injection system. The 5.8 V8 is optional in the Grand Wagoneer and J-10, and standard in the J-20

SPECIFICATIONS

Displacement 5.9 litres (360 cubic inches) Type: 90 degree V-8

Bore 4.08 inches Stroke 3.44 inches Compression ratio 8.25:1

Cylinder head volume 58 - 61 cc

Horsepower 144 @ 3200 rpm Torque 280 @ 1500 rpm

Firing order 1-8-4-3-6-5-7-2

Crank cast nodular iron

Deck height 9.205 inches

Main journal diameter 2.75 inches

Rod journal diameter 2.09 inches

Valve diameter Intake 2.025 inches Exhaust 1.680 inches