Press Kit: 2007 Chrysler Pacifica Reveal

The leading goals guiding the development of the new Chrysler Group 4.0-liter SOHC V-6 were impressive low-rpm torque and extremely smooth and quiet operation.

“When we decided to create a more powerful V-6 for Chrysler Group vehicles, we invested in building on the dependable 3.5-liter V-6,” said Bob Lee, Vice President, Chrysler Group Powertrain. “The new 4.0-liter V-6 delivers more power than any naturally aspirated V-6 engine in our vehicles, and does so with world-class smoothness and refinement.”

The new engine has impressive low-rpm torque that will give customers very good engine response around town and provide the power they expect from a world-class V-6. The 4.0-liter V-6 produces 255 hp @ 6,000 rpm and 265 lb-ft of torque @ 4,200 rpm. The engine produced 15 more lb-ft of torque at peak power rpm, and as much as 35 lb-ft more torque throughout the power curve.

Specific changes from the 3.5-liter engine for improved power include: 

• Crankshaft stroke increased from 2.47 in. (81 mm) to 2.78 in. (91mm) 
• Displacement changed from 214.7 cu. in. (3.518 liters) to 241.2 cu. in. (3.952 liters) 
• New camshaft profile featuring higher lift and revised timing events 
• New upper intake manifold with improved flow 
• Compression ratio raised from 10.0:1 to 10.2:1

Equally important are the decreases in engine noise, vibration and harshness (NVH). More than 10 engine characteristics were designed specifically for minimal engine noise, and to ensure that the sound would remain pleasing to the driver. The result is an engine with equal or better NVH qualities than competitive benchmark engines.

Specific changes from the 3.5-liter engine for decreased NVH include: 

• Increased main-bearing width and diameter 
• Tighter crankshaft balance spec 
• Select-fit rod bearings 
• Reduced reciprocating mass piston assemblies 
• Added ribbing to the sides of the engine block 
• Increased pan-rail thickness on block 
• Direct-mount oil pan to transmission bell housing 
• Thermoplastic valve cover 
• New "low rumble" intake manifold 
• Intake lobes splayed 
• Equal length exhaust

The 4.0-liter V-6 utilizes an semi-permanent mold cast aluminum block with iron liners and cast-aluminum cylinder heads. It is a single overhead camshaft (SOHC), 24-valve engine. The engine is produced at the Trenton Engine Plant in Trenton, Mich., and will debut first in the 2007 Chrysler Pacifica, followed later this year by the 2007 Dodge Nitro.