Chrysler 4.7L V8 PowerTech Engine (Design, Issues & Reliability)

✔ This article has been fact checked.

Chrysler created the 4.7L V8 PowerTech engine producing 325-310 hp, it made its debut in the Jeep Grand Cherokee in 1999 before being employed in Dodge cars from 2000 to 2002.

The 4.7L V8 was the first engine of the PowerTech series, created to replace the 316 V8s from Chrysler and the 4.0L inline-six engine from AMC in the LA family.

The new 4.7-liter V8 engine in Dodge vehicles was briefly known as the 4.7L Magnum, although having nothing to do with the earlier 5.2L Magnum.

In 2002, the PowerTech series was expanded to include the Chrysler 3.7L V6 engine that resembled the V8 model almost exactly but with two less cylinders.

Table of Contents:

• Design

• Specs

• Problems & Reliability

• Images

Chrysler 4.7L V8 PowerTech Engine Design

The 4.7L PowerTech has a cast-iron cylinder block that is suitable for employing one crankpin journal for two connecting rods, with a bore spacing of 4.09 inches (104 mm), a deck height of 9.09 inches (231 mm), and a 90-degree angle between cylinder banks.

From the ground up, the engine block was totally reworked. The first engine had a nodular cast-iron crankshaft that was connected to the block by a single bedplate rather than five independent main-bearing covers. The bedplate made of compressed graphite iron stiffens the block and dampens vibration and noise.

This engine has cast aluminium pistons with moly coated skirts and powder-forged fracture-split metal connecting rods (6.12 inches/155.5 mm in length). A stamped steel oil pan seals the crankcase from the bottom. This 4.7L engine lacks a balance shaft, but the 3.7L V6 engine has one.

The engine's cylinder heads are made of a cast aluminium alloy. A gasket made of three layers of laminated stainless steel separates each head from the engine block. The head bolts are 11 mm in diameter.

Only two valves and a single top-mounted, chain-driven hollow camshaft are present in each cylinder head (SOHV design).

The intake and exhaust valves are pushed apart while the rocker arms are rotated 180 degrees. Because of this configuration, the combustion chamber design and the placement of the spark plugs were both improved (almost hemispherical chambers).

The exhaust valves have a 1.46-inch (48 mm) diameter, while the intake valves are 1.89 inches (37 mm) in diameter.

• There is 0.443 inches of lift on the intake valve and 0.429 inches of lift on the exhaust valve.

• The exhaust has a duration of 254 degrees, while the intake has a duration of 244 degrees.

• An electronic throttle body (drive-by-wire) manages the engine's speed. The diameter of the throttle valve is 2.56 inches (65 mm).

There is a cast magnesium valve cover above each cylinder head. Hydraulic lash adjusters are located in the valvetrain.

This engine is equipped with electronic sequential multi-port fuel injection. The intake port on the cylinder head is where the fuel injectors are attached.

The newly designed tuned-length runner intake manifold is constructed of a polymer material. A hybrid cooling fan system and a modern coil-on-plug ignition system is also used.

High-Output Engine

A "High-Output" version of the 4.7L PowerTech engine was added to the Jeep Grand Cherokee Limited in 2002 and was made standard on Overland variants. 

The differences include:

• A 9.7:1 compression ratio

• High-compression domed pistons

• Two knock sensors

• Different camshafts

• Reworked intake

Compared to a typical engine, this one boasts 35 more lb-ft of torque and 30 more hp.

The 4.7L high-output version of the Jeep Grand Cherokee was discontinued in 2005 and replaced with a 5.7L V8 Hemi; nevertheless, some vehicles continued to be offered with it until 2008.

The regular version model acquired knock sensors and other small upgrades around 2005.

2008 Engine

The 4.7L V8 PowerTech engine received some significant changes in 2008.

2008 redesigned engines have:

• Lighter connecting rods made of 36MnVS4 steel and forged steel pistons.

• A compression ratio that was raised from 9.0:1 to 9.8:1.

• Modified cylinder head ports to improve flow.

• A new valve lash adjustment mechanism was included in the valvetrain.

• A new 2.91-inch throttle body.

• An improved intake manifold with shorter runners.

• A more aggressive camshaft profile.

The Dodge Ram 1500 featured the PowerTech V8 4.7L engine for the longest period of time, up until the 2013 model year.

The 3.6L V6 Pentastar and modern Hemi V8 engines, which were more technologically advanced, took the place of this 4.7-liter V8 engine.

Engine Specs

• Manufacturer: Chrysler, Mack Avenue engine plant, Detroit, Michigan

• Production years: 1999-2013

• Cylinder block material: Cast iron

• Cylinder head material: Aluminium

• Fuel type: Gasoline

• Fuel system: Sequential multi-port fuel injection

• Configuration: V

• Number of cylinders: 8

• Valves per cylinder: 2

• Valvetrain layout: SOHC

• Bore: 93.0 mm (3.66 in)

• Stroke: 86.5 mm (3.40 in)

• Displacement: 4,698 cc (286.7 cu in)

• Type: Four-stroke, naturally aspirated

• Compression Ratio: 9.0:1, 9.7:1 (High-Output version), 9.8:1 (2008+)

• Power: 235-310 hp (175-231 kW) at 4,600-5,650 rpm

• Torque: 295-334 ft-lb (400-453 Nm) at 3,600-4,000 rpm

• Firing order: 1-8-4-3-6-5-7-2

• Engine oil weight: SAE 5W-30 (SAE 5W-20 from 2008)

• Engine oil capacity: 5.7 litres (6.0 qt) - with oil filter

• Oil change interval: 6,000 miles (10,000 km) / 6 months

• Applications: Jeep Grand Cherokee, Jeep Commander, Dodge Ram 1500, Dodge Dakota, Dodge Durango, Chrysler Aspen, Mitsubishi Raider

Problems & Reliability

The 4.7L V8 PowerTech is a reliable engine with a simple layout. It has a solid cast-iron bedplate and block, fewer electrical components that could malfunction, and robust timing chains.

• Early versions experienced issues with hydraulic lash adjusters that failed, which might cause rocker arms to kick out of their intended positions.

• The second issue is more common with these V8 PowerTech engines than the V6s. It is possible that some valve seats will come out when the engine overheats because the cylinder head's valve seats are not adequately secured..

If the engine has routine maintenance, it could last around 150,000 miles (240,000 kilometres). The PowerTech engine family, however, does not react well to extended periods without oil changes and servicing.

The engine requires thin oils and frequent oil changes; failing to change oil frequently can cause serious issues with the engine.

Images

Below are images of the Chrysler 4.7L PowerTech engine.

Inside View of the Chrysler 4.7L V8 PowerTech

Sources