Phoenix: Chrysler Pentastar V6 Engines for 2010 and Beyond

Inside the Trenton engine factory

Power ratings for the Jeep Grand Cherokee are at least 290 horsepower and 270 lb.-ft. of torque (353 N•m) @ 4,800 rpm, before direct injection; retuning is expected to raise power levels somewhat for the Dodge Challenger, and direct injection should break the engine into the over-300 realm (though not until the 2012 or 2013 model year).

Around 440,000 Pentastar engines are to be made each year, hooked up to the 6xTE, WA580, and Fiat's dual-clutch automatics.

As of May 25, 2010, engine block glitches were keeping production low, but standards are being kept high, with low production preferred to pushing poor quality engines out the door. Production seemed to be up to 300 per day with much lower scrap. We were told that the same teething issues happened with past engines, including the sturdy 3.3 V6 and the new 4.0 liter V6. Apparently, while the kinks in block production are being worked out, more people are being put onto block production while the final assembly area remains on a single shift.

90% of torque is available from 1,600 to 6,400, so it's not a “peaky” or “paper horsepower” engine. Engineers are reportedly hard at work, seeing what they can do to keep increasing power even without direct injection, which seems to be on the back burner.

A test batch of engines were made in February, and sent to Roush Industries (which preps the Challenger drag cars) for extensive hot testing, to find any problems before customers do. There have been some production delays (as of April 2010), due to defective parts from Asia and issues with the blocks; but to its credit, Chrysler is rejecting bad parts and shutting down production rather than going ahead and “fixing it later.” This might mean a brief shortage of Pentastar V6 engines at first, but the company started production far in advance to be able to overcome any potential issues without time pressure.

A twin turbo and single-turbocharger version are planned, for introduction by 2014; both would be based on the smallest size (3.0 liters) and might be slated for limited-production models (e.g. a new Viper based on a Maserati or an SRT mid-sized car). The twin-turbo version appears to projected for a whopping 420 horsepower while the single-turbo appears to be set for 370 hp.

A 3.3 liter version is planned, with projected output of 280 hp, along with the current 3.6 liter version; a base 3.3 without MultiAir or direct injection seems to be slated for around 260 hp. (These horsepower figures are estimates, and final ratings may vary. The addition of MultiAir, as opposed to the current variable valve timing system, may not have the expected impact.)

Here are some of the major innovations, as far as we can tell:

• Variable cam timing with dual independent cam phasing that helps to flatten the power output (The system uses separate cam phasers on each cam, so it can change the intake and the exhaust valve timing, achieving the same results as the dual variable valve timing system on the World Engine, but with a simpler, more durable design.)
• Exhaust manifold integrated into the head itself
• A chain drive replaces the usual timing belt, for greater longevity and accuracy.
• Canister-free oil filter element — prevents landfill, allows incineration; also eases DIY oil changes and prevents ham-fisted oil change places from "holing" or over-tightening the filter
• Oil to antifreeze oil cooler in the "V"
• All accessories bolted directly onto the block to avoid vibration and noise
• Lightweight block — saves on aluminum and reduces overall vehicle weight (improving balance, too)
  • High-pressure die-cast blocks save on labor, have thinner walls, and are 20 pounds lighter than GM’s V6 blocks, saving around $40 per engine on aluminum and contributing to much lower build costs than GM’s engines.

The engine features high-flow intake and exhaust ports, which in combination with dual independent cam phasing, allows optimum volumetric and combustion efficiency over the full speed and load range. This results in an exceptional, flat torque curve along with high specific power. The engine’s torque exceeds 90% of its peak value from 1,600 to 6,400 rpm, which provides outstanding drivability and responsiveness.

Early Pentastar V6 engines do not have direct injection, but it is in the works for the future.

Refinement was achieved with the help of advanced computer-aided engineering. Structural, intake, and exhaust areas deliver low levels of noise. Idle quality was improved through the dual independent cam phasing.

The advanced oil filter system eliminates oil spills and contains an incinerable filter element instead of the typical spin-on filters, which are disposed of in landfill sites; the filter is conveniently located on top of the engine. The use of long-life spark plugs, regular gasoline, and a high-energy coil-on-plug ignition system also helps to reduce cost of ownership. The engine also is fully flex fuel capable, offering consumers the choice of gasoline or E85 fuel without any degradation in performance or emissions.

Material	Liquid cooled 60-degree V6 with deep-skirt aluminum block and heads
Valves	Chain driven DOHC with 24 valves. Roller finger followers and hydraulic lash adjusters. Dual independent cam-torque actuated phasers.
Displacement	220 cid / 3.6 liters
Bore x Stroke	3.78 x 3.27 (96 x 83 mm)
Fuel injection	Returnless, sequential. Direct injection to be on future, turbocharged, 3-liter variants.
Compression	10.2:1
Fluid	6 quarts 5W20 oil; 14 quarts antifreeze; regular gas
Redline	6,400 rpm (stated elsewhere as 7,200 rpm)
Power	280 hp (209 kw) @ 6,400; 260 lb-ft (353 Nm) @ 4,800
Emission controls	Dual three-way catalytic converters, heated oxygen sensors, internal features
Assembly	First: Trenton Engine Plant, Michigan

Running on regular gas, the Pentastar engine is estimated for 16 mpg city, 23 highway on the Grand Cherokee — vs 16/20 for the Hemi. It meets California LEV II+ evaporative emission requirements, Tier 2, meets Federal Bin 4+ emission requirements, and Clean Fuel Fleet Certification (CCF-LEV) in all other states.

The Phoenix engine was renamed to “Pentastar” very recently, due to a hitherto unknown trademark-name conflict (though representatives claim there was no conflict, and the renaming was intentional).

Spark plugs are installed at the end of a length tube. There is a spring running through the length of the tube, from the conventional-looking plugs up to the coils; we do not know whether the entire tube is removed, or (as we believe) the plug is removed via the spring, which is attached to the contact.

The Pentastar V6 is an interference design; it has valve reliefs but only for clearance under normal conditions. It does have a timing chain, reducing the possibility of heavy damage from a snapped belt. (Thanks, Keith.)

The engine accessories have no brackets; they are bolted directly to the block, cutting vibration. Since the air conditioner compressor and alternator are both bolted to the block, a tensioner is used with the serpentine belt to maintain appropriate tension. The Phoenix engine was designed to be used in either a North-South and East-West configuration.

Despite the tremendous potential of the Pentastar V6, it was actually endangered not by Daimler, which intended to use the design in Mercedes cars — and most likely still intends to use it in Mercedes cars, though without admitting its pedigree — but by Cerberus, which seriously considered bringing over Nissan engines instead, to cut development costs. The Pentastar reportedly did 7% better in fuel economy than the Nissan engine, for the same power output.

The new state-of-the-art Trenton (Mich.) Engine South plant will be the lead facility for production of the Pentastar V-6 engine. A duplicate facility in Saltillo, Mexico, will ramp up for the 2012 model year. Production has started as of March 2010.

This report came on November 3, 2008:

Even the most powerful Phoenix, displacing 3.6 liters and producing (in preliminary tests) over 280 horsepower, is quieter than Toyota’s 3.3 liter V6 - and far quieter than the Toyota 3.5 liter V6. Gas mileage is said to be good, partly due to the use of high-pressure, die-cast blocks, which save on labor and allow for thinner walls and less use of aluminum. These blocks are 20 pounds lighter than General Motors‘ V6 blocks, saving around $40 per engine on aluminum alone; an independent firm estimated that these engines are at least $300 cheaper to build than GM’s current V6 line.

Chrysler wrote that: “The new Phoenix of V-6 engines will feature cylinder deactivation (MDS)...the engine will operate efficiently on three cylinders when less power is needed, and in V-6 mode when more power is needed. This optimizes fuel economy when V-6 power is not required – without sacrificing vehicle performance or capability.

“The new family of V-6 engines will feature an aluminum die cast block, dual variable valve timing (VVT) and a two-stage oil pump, among other technologies. The end result is an expected across-the-board V-6 fuel efficiency improvement of six to eight percent – in addition to new levels of V-6 power, performance and refinement.” Allpar note: the key words here are both performance and refinement!

The following table was first provided in July 2006 with information from oh20, in a form not dissimilar from its current state; he updated the chart at the end of November 2008 to the following. All engines have variable valve timing unless otherwise noted.

Size	Line	Cars
3.0 V6	Base Premium Direct Injection MDS	Export models (four different varieties are apparently planned though volume will probably be low)
3.3 V6	VVT	Sebring, Avenger, Minivans
3.3 V6	Direct Injection	Challenger, Charger, Minivans, Grand Cherokee, Durango, Aspen
3.3 V6	DI/HEV	Sebring, Avenger, 300, Minivans
3.3 V6	MDS	Sebring, Avenger, Minivans
3.6 V6	VVT	Multiple models (first on Grand Cherokee)
3.6 V6	Direct Injection	Ram, Wrangler (Since the noise will be acceptable)
3.6 V6	MDS (late intro)	Challenger, Charger, 300, Minivans, Grand Cherokee, Durango, Aspen
3.6 V6	HEV	Minivans
3.6 V6	PZEV	Sebring, Avenger, Minivans
4.0 V6	Base (no VVT)	marine use
4.0 V6	Premium, MDS, no VVT	marine use
4.7 V8	VVT	Ram, Charger, 300, Dakota, Grand Cherokee, Durango, Aspen

Chrysler has announced details, including the investment in plants ($2 billion, not including engineering of the engines themselves) and the fact that Mercedes will share the basic engine architecture. The Phoenix engines, long discussed on Allpar's news and rumors forum, will be made in Mexico, Kenosha (Wisconsin), and Trenton (Michigan), with parts machined in Toledo, Ohio. Allpar at least is happy that development of these engines appears to be centered in the US though no doubt Mercedes will get most of the credit for their success.

The old Trenton Engine plant will close in 2014; the new Trenton Engine plant will open in time for the 2010 model year.

At the latest, the current V6 engines (dating back to around 1990) will be phased out in 2013, except for the 3.8 and 4.0 V6, which should finished by 2014.

Dieter Zetsche said the new engine family would operate on a modular base. The world's best V6 engines were benchmarked; and Mercedes has a camless design that may be integrated into Auburn Hills’ work. The engines will be built on flexible assembly lines that will allow the mix to be changed quickly and easily. Plants will have job rules that include 10 hour four-day work weeks and two job classifications.

The Phoenix engines were first discussed by "superduckie" way back in March 2006. oh20 (who has been accurate on the Ram, Challenger, Caliber, and Sebring) provided a table of the engines and cars they’d go into back in July 2006.

Production details

• TB007 wrote: “The mystery item behind the oil filter is probably an oil to water oil cooler. The engines do not seem to have exhaust manifolds, but rather the head is cast with an exhaust flange to one side.” (This turned out to be right.)
• (From 2008) An investment of $730 million for a new plant in Trenton, Mich., to produce the "Phoenix" family of V-6 engines. The new Trenton plant, located adjacent to the existing Trenton Engine Plant, will have an annual capacity of 440,000 engines and is expected to begin production in 2009. The Phoenix family of engines is the first of these initiatives that will go into production. In the long term, the Phoenix engines will replace the current four V-6 engines.
• An investment of $700 million to build a new axle plant in Marysville, Mich. The facility will create a new family of axles that provide better fuel economy. The common axle family will enable the company to consolidate the number of axles for better economies of scale. This plant will be run by ZF.

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