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Chrysler 5.7L Hemi 345 Engine Review

5.7L Hemi 345 Engine

In 2003, Chrysler introduced the third generation Hemi engine family. The first released engine was a 345 cu in / 5.7-liter V8 gasoline Hemi version for the 2003 model year Dodge Ram pickup trucks. The 5.7L Hemi (code name is Eagle) replaced the 5.9-liter V8 LA/Magnum engine. In the next couple of years, this 345 Hemi engine became available in numerous models produced by Chrysler: Dodge Durango, Chrysler 300C, Dodge Magnum R/T, Jeep Grand Cherokee, Dodge Charger, and others.

The 5.7L power unit was a completely new engine designed from scratch. Like the 4.7L PowerTech V8, the 345 Hemi engine has a cast-iron cylinder block with a deep-skirt design and a 90-degree angle between cylinder banks. The crankshaft made of cast nodular iron is supported by four bolts per main bearing. It uses powdered metal connecting forged rods and lightweight aluminum, skirt-coated pistons. Up through 2008, pistons had wider rings - 1.50/1.50/3.0 mm rings. After the revision in 2009, pistons were equipped with narrow piston rings - 1.20/1.20/2.0 mm ring pack. The chain-driven camshaft is located between cylinder banks. The timing chain is relatively long, as the camshaft is intentionally raised up to reduce the length of the pushers (lighter parts - less inertia).

The 5.7 Hemi engine has aluminum cross-flow cylinder heads with two valves and two spark plugs per each cylinder. The HEMI-shaped chambers now have flatter design with squish shelves on both sides, increasing efficiency and reducing emissions. The camshaft actuates intake and exhaust valves by pushrods via rocker arms. The engine also equipped with beehive valve springs and roller-style hydraulic lifters. To reduce fuel consumption and harmful emissions, the engine was designed with a cylinder deactivation system called MDS (Multi-Displacement System). This system turns off the fuel in four cylinders (two in each bank) and keeps intake and exhaust valves closed by controlling the flow of oil through the lifters of corresponding valves. The diameter of intake valves is 2.00 inches (50.8 mm), of exhaust valves - 1.55 inches (39.4 mm). The intake manifold made of plastic. There is also an electronic throttle body (drive-by-wire).

In 2009, Chrysler released the revised 5.7L Hemi with some upgrades designed to improve the efficiency and environmental friendliness of this big motor. The biggest thing was the implementation of the variable valve timing (VVT), which required three additional oil passages and an extended front cam bearing in the block. The redesigned engine block comes with a new and very strong crankshaft which by the way still made of cast iron (a 53021300BB casting). There are dual-mass crankshaft damper, reinforced connecting rods, and new pistons for the narrower ring pack. Starting from 2009, some models feature an electronically controlled, variable length of the intake runner (the active intake).

Cylinder heads have undergone significant changes. The new, bigger and almost square intake ports flow 14% more air than previous rectangular ones. The D-shaped exhaust ports have a raised roof. The intake valves are 2 mm larger. While the original heads have round 85cc chambers with squish shelves, the new ones have 65cc oval chambers. The compression ratio was increased to 10.5:1.

After the 4.7-liter V8 PowerTech was discontinued in 2013, the 5.7L Hemi motor became the base V8 engine option.

Engine Specs

Manufacturer
Chrysler, Saltillo Engine plant in Ramos Arizpe, Mexico
Production years
2003-present
Cylinder block material
Cast iron
Cylinder head material
Aluminum
Fuel type
Gasoline
Fuel system
Sequential multi-port fuel injection
Configuration
V
Number of cylinders
8
Valves per cylinder
2
Valvetrain layout
OHV
Bore, mm
99.49 mm (3.92 in)
Stroke, mm
90.88 mm (3.58 in)
Displacement, cc
5,654 cc (345 cu in)
Type of internal combustion engine
Four-stroke, naturally aspirated
Compression Ratio
9.6:1;
10.5:1 - 2009+ model years
Power, hp
340-395 hp (254-295 kW)/5,000-5,600
Torque, lb ft
375-410 ft-lb (508-556 Nm)/3,950-4,400
Engine weight
560 lbs (254 kg)
Firing order
1-8-4-3-6-5-7-2
Engine oil weight
SAE 5W-20
Engine oil capacity, liter
6.7 l (7.0 qt) with oil filter
Oil change interval, mile
6,000 (10,000 km)/6 months
Applications
Ram 1500/2500/3500, Dodge Durango, Chrysler 300 300C, Dodge Magnum (R/T), Dodge Charger (R/T), Jeep Grand Cherokee, Jeep Commander, Chrysler Aspen, Dodge Challenger

5.7L V8 Hemi Engine Problems and Reliability

In general, the third-generation Hemi V8s don't have any significant design flaws, and the 5.7L version is a solid reliable engine. Many owners are faced with a strange ticking sound in the 5.7L Hemi engine coming from the valvetrain, which, however, does not affect anything. This "the tick" is common for modern Hemi V8s with the MDS system. There was one well-known problem with the dropping/cracking of valve springs which existed in early Hemi engines until 2007 when the manufacturer solved this problem by replacing them with newly revised springs.

It is also worth noting the high sensitivity of the cylinder deactivation system (MDS) to the condition of the oil. To avoid problems, it is necessary to strictly follow the oil change schedule and use only the recommended oil. Another not very pleasant feature of the 5.7 engine is two spark plugs per cylinder or 16 in total that require replacement every 30,000 miles, which can be quite expensive.

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