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AN: New Pentastar engines: 3.0, DI, MA2?

13K views 52 replies 29 participants last post by  MoparNorm 
#1 ·

Some time ago, we were told that a small number of unfinished Pentastar blocks had been sent out to Europe. We assumed then that they were to be used by Maserati, but additional information, including being able to examine the new Maserati V6, voids that assumption. Based on the information we have now, the blocks are for the upcoming 3.0 liter Pentastar V6, which Allpar first discussed years ago. The 2.997 liter V6 was designed to avoid higher European displacement-based taxes (2.997 is under 3 liters), and is likely to be used in European versions of Chrysler/Lancia cars and to be an option for Alfa Romeos. While it would likely be cheaper to engineer and finish them in the United States, American engineers have been running full tilt on other projects, and production facilities are equally booked; indeed, the twin Pentastar engine plants have been running on overtime and the..

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#2 ·
Interesting.

I see an advantage in that if the Europeans manage to take the Pentastar and make a 3.0L sing like a 3.6L with Multiair and other tech, then those tech advances could possibly be brought back to the 3.6L for a higher output option, or the 3.0L engine in its entirety could be redomesticated as a lower option to increase the breadth of choices to make more entry-level vehicles if that's a segment identified as being under served...
 
#3 ·
My guess is that direct injection will eventually transition. I'm not sure MA2 will ever be worth the added expense here. At least not unless fuel prices really rise and I doubt that will happen, for various reasons, any time soon. (And when it does we're more likely to simply move to four cylinders.)
 
#4 ·
DaveAdmin said:
DaveAdmin, on 29 Jan 2013 - 10:37, said:
My guess is that direct injection will eventually transition. I'm not sure MA2 will ever be worth the added expense here. At least not unless fuel prices really rise and I doubt that will happen, for various reasons, any time soon. (And when it does we're more likely to simply move to four cylinders.)
I keep reading about the cost of MA, but what is that based off? Has an insider indicated what the added cost is? Or is this based off comments from management? Is it material intensive, or is labor intensive, or if scalability is currently an issue. I keep hearing it's expensive, but of course the explanation stops there. Is it something in which the cost would be more mitigated upon larger scale adoption?
 
#5 ·
bumonbox said:
I keep reading about the cost of MA, but what is that based off? Has an insider indicated what the added cost is? Or is this based off comments from management? Is it material intensive, or is labor intensive, or if scalability is currently an issue. I keep hearing it's expensive, but of course the explanation stops there. Is it something in which the cost would be more mitigated upon larger scale adoption?
I'm thinking the same thing. I won't pretend to know costs involved, but I do wonder, "How much more expensive?" Prohibitively so? Expensive, but it might come down with the passage of time (in general, technology becomes cheaper with time) or with economies of scale?

Also, I assume they factor in how overall performance (HP, torque, and fuel economy) might affect sales, correct? For example, I'm guessing they can roughly predict how sales might improve if an engine outperforms its competitors in both power and economy, despite a cost increase of X.
 
#6 ·
DaveAdmin said:
My guess is that direct injection will eventually transition. I'm not sure MA2 will ever be worth the added expense here. At least not unless fuel prices really rise and I doubt that will happen, for various reasons, any time soon. (And when it does we're more likely to simply move to four cylinders.)
Agreed, especially if you take into consideration that one of the principal advantages of MA2 (over MA1) is the reduction in CO2 and other pollutants, something that is more of a USP in Europe than in the US.

bumonbox said:
I keep reading about the cost of MA, but what is that based off? Has an insider indicated what the added cost is? Or is this based off comments from management? Is it material intensive, or is labor intensive, or if scalability is currently an issue. I keep hearing it's expensive, but of course the explanation stops there. Is it something in which the cost would be more mitigated upon larger scale adoption?
More expensive than DVVT, lets put it like that ;)
 
#7 ·
Engineering theory on ICEs indicates that the theoretical highest efficiency obtainable in an ICE occurs when it is operating in "Homogenious Charge Compression Ignition" mode.  HCCI is a combination of both gasoline spark ignition, (ie conventional gasoline engines) and the heavy weights of Compression ignition ( ie Diesel cycle ) operation.  It would combine the lightness of gasoline (Otto cycle) engines, with better fuel economy of Diesel cycle, without the weight penalties, and pollution concerns. 

Most current Compression Ignition engines are comparatively quite crude affairs, unable to control the precise ignition points and are simply "beefed up" to endure the pre-ignition problems, that would tear apart a lighter OTTO cycle ICE.  That is the source of the so-called Diesel "clatter".    

This HCCI mode is a very tough to obtain mode of operation, switching back and forth in each individual cyclinder in each combustion cycle.

To accomplish this, lab test HCCI test engines have certain features. Precisely measured fuel charges  provided by Direct Injection, precise control of the air mixture provided by individual valve control for both valve lift and valve duration for each  individual cyclinder for each individual cylinder combustion cycle. Homogeneous charge provided by a tailored combination of fuels, provided today, by a mixture of flammable fuel and air and non-flammable ( pre-burnt) fuel-air are provided by controlling the Exhaust Gas Recycling or EGR, metered by the variable exhaust and intake valves.  Compression ignition typically requires an excess of air, typically provided by a turbo or supercharger.  Plus the engines have to be slightly beefed up to handle boost, but not as heavily weighted as Diesel engines. 

In their search for the almost mythical HCCI efficiency, additional features for a ICE engines are typically needed.  But MultiAir's variable valve lift and duration, plus Direct Injection, pluss controlled EGR, and volumetric air control provided by a Turbo/supercharger are merely the "ante up", to consider HCCI being able to operate.

Fast and accurate control of timing of the spark /no spark decsion on a cyclinder by cyclinder basis, can be provided by modern electronic ignition system and real-time feed back controls from sensors,mounted on the engine which are also necessary.  Clean air requirements have lead to such sensors being installed on today's NAFTA engines. These might have to be  duplicated or made fast enough for per cylinder decisions.  That would require  more computer power in the electronic controls, but computer power is growing and is fairly cheap. But the software is NOT.  An ICE equipped with  MultiAir, DI, EGR, turboboost,  real-time feedback Sensors, and  sufficiently powerful computer controls, has virtually EVERY NECESSITY and FACILITY, to run in HCCI mode.

After Multiair and DI is available it is but a small step for Chrysler to attain this most efficient theoretically possible mode of ICE operation.  Something to be sought in the quest for CAFE targets, and better fuel mileage.  
 
#8 ·
ChryslerFiatfan said:
Engineering theory on ICEs indicates that the theoretical highest efficiency obtainable in an ICE occurs when it is operating in "Homogenious Charge Compression Ignition" mode.  HCCI ...
Sounds like witchcraft.
 
#11 ·
ChryslerFiatfan said:
Engineering theory on ICEs indicates that the theoretical highest efficiency obtainable in an ICE occurs when it is operating in "Homogenious Charge Compression Ignition" mode.  HCCI is a combination of both gasoline spark ignition, (ie conventional gasoline engines) and the heavy weights of Compression ignition ( ie Diesel cycle ) operation.  It would combine the lightness of gasoline (Otto cycle) engines, with better fuel economy of Diesel cycle, without the weight penalties, and pollution concerns. 

Most current Compression Ignition engines are comparatively quite crude affairs, unable to control the precise ignition points and are simply "beefed up" to endure the pre-ignition problems, that would tear apart a lighter OTTO cycle ICE.  That is the source of the so-called Diesel "clatter".    

This HCCI mode is a very tough to obtain mode of operation, switching back and forth in each individual cyclinder in each combustion cycle.

To accomplish this, lab test HCCI test engines have certain features. Precisely measured fuel charges  provided by Direct Injection, precise control of the air mixture provided by individual valve control for both valve lift and valve duration for each  individual cyclinder for each individual cylinder combustion cycle. Homogeneous charge provided by a tailored combination of fuels, provided today, by a mixture of flammable fuel and air and non-flammable ( pre-burnt) fuel-air are provided by controlling the Exhaust Gas Recycling or EGR, metered by the variable exhaust and intake valves.  Compression ignition typically requires an excess of air, typically provided by a turbo or supercharger.  Plus the engines have to be slightly beefed up to handle boost, but not as heavily weighted as Diesel engines. 

In their search for the almost mythical HCCI efficiency, additional features for a ICE engines are typically needed.  But MultiAir's variable valve lift and duration, plus Direct Injection, pluss controlled EGR, and volumetric air control provided by a Turbo/supercharger are merely the "ante up", to consider HCCI being able to operate.

Fast and accurate control of timing of the spark /no spark decsion on a cyclinder by cyclinder basis, can be provided by modern electronic ignition system and real-time feed back controls from sensors,mounted on the engine which are also necessary.  Clean air requirements have lead to such sensors being installed on today's NAFTA engines. These might have to be  duplicated or made fast enough for per cylinder decisions.  That would require  more computer power in the electronic controls, but computer power is growing and is fairly cheap. But the software is NOT.  An ICE equipped with  MultiAir, DI, EGR, turboboost,  real-time feedback Sensors, and  sufficiently powerful computer controls, has virtually EVERY NECESSITY and FACILITY, to run in HCCI mode.

After Multiair and DI is available it is but a small step for Chrysler to attain this most efficient theoretically possible mode of ICE operation.  Something to be sought in the quest for CAFE targets, and better fuel mileage.  
Great post! Unless I'm mistaken, MA2 has "conquered" the second step; controlling EGR on a per cylinder basis. DI has been tested from what I've heard on the Italian side, but packaging all that stuff in there must be a real challenge.
Sincere compliments to those guys that painstakingly programmed MA lift and opening (and now EGR).
 
#12 ·
Bob_Sheaves said:
Think about what you guys are asking....

The timing phaser on each cam adjusts all cylinders for that cam in exactly the same manner, to all the same degree (given the manufacturing tolerances of the parts- there ain't ANY adjusted EXACTLY the same, EVERY time)... Now, with MA2, you are adjusting each cylinder to what IT needs. Think about the parts count, the electronics controls, and processing power/software drivers.

TANSTAAFL.
That does help to put it in perspective. It seems like, over time it would be more possible to streamline the costs of the latter 2. Of course that is a pure guess. Not much you can do about the first I would think. Perhaps over time they will have continue to develop it, may find other ways to reduce cost. I suppose it's still fairly new.

I have been wondering, also about DI, and it's cost. I also understand that DI increases NVH. I have been curious about that, is DI particularly costly, or is the bigger issue perhaps attempting to mitigate the increased NVH? Needless to say, they will have to fight to keep the upcoming cars competitive in fuel economy and what not, and while the 3.6 is good, I imagine it will be beneficial to continue improving it, especially in light of CAFE.
 
#13 ·
bumonbox said:
Well I got that.. :p
Let's put it this way: if you ever break it, changing a "MA head" will likely run you about 1.5-2k...for an I4.

EDIT: actually, let me fix that otherwise you'll get the wrong idea. The actual MA module will run you about 1k, but it's not a walk in the park to substitute it. Labor is gonna cost you.
 
#14 ·
What I don't get is with all the extra costs of R&D, tooling, manufacturing, and stocking extra parts etc etc, why didn't Chrysler just go with two engines, the 3.0 and the 3.6 instead of incurring the additional costs for three engine sizes within about 35 cu in of each other? On one hand they keep saying there's no money for this or that (such as two mini vans etc), but there is plenty of money for three engines within such a small size difference. The 3.0 and 3.2 are about 12 cu in different in size. Nuts....
 
#15 ·
3.6 is the original, relatively low-tech (for this series) engine, should be good for torque and truck use.
3.2 is optimized for higher gas mileage.
3.0 is optimized for Europe: costs more (if I'm right), but falls under the 3+ liter tax, and is more suited to a region where the V6 gas engine is an upscale unit and fuel is very pricey.
 
#17 ·
willy said:
What I don't get is with all the extra costs of R&D, tooling, manufacturing, and stocking extra parts etc etc, why didn't Chrysler just go with two engines, the 3.0 and the 3.6 instead of incurring the additional costs for three engine sizes within about 35 cu in of each other? On one hand they keep saying there's no money for this or that (such as two mini vans etc), but there is plenty of money for three engines within such a small size difference. The 3.0 and 3.2 are about 12 cu in different in size. Nuts....
During the 90s, we were swimming in a sea of V6s. for awhile, we had a 2.7L V6, a 3.2L V6, and a 3.5L V6 all from the same family. At the very same time, we also had a 3.3L V6 and a 3.8L V6. At least we are downsizing a little bit.

http://www.allpar.com/mopar/V6/35.html



DaveAdmin said:
3.6 is the original, relatively low-tech (for this series) engine, should be good for torque and truck use.
3.2 is optimized for higher gas mileage.
3.0 is optimized for Europe: costs more (if I'm right), but falls under the 3+ liter tax, and is more suited to a region where the V6 gas engine is an upscale unit and fuel is very pricey.
If i was king during that decision, i would have just done a 3.0L (optimized for Europe and higher gas mileage) and a 3.6L truck engine.



ps: just remembered the mitsu V6s :blink:
 
#19 ·
This time, it's a large number of specific applications of a single engine family.

Last time, let's see:

LH family (so named, but the 3.3 came before the LH) -- 3.3, 3.5, 3.8, 4.0
"AMC" truck engine -- 3.7
"6/8 of a 360 V8" engine -- 3.9
MMC 3.0 and 2.5

Why?

Well... first came the Mitsu 3.0. Chrysler was going to buy all of Mitsubishi, so that made sense -- their future division made an engine that they needed, so they bought it for the few vehicles that really needed them. As time went on, it must have dawned on people that they could build something better suited to their needs, cheaper, and that fuel would not be getting scarce again any time soon, so V6 demand would stay.

So then the 3.3 was born. It met their power needs, sitting above the 3.0, and complementing it. They still bought the 3.0, partly to avoid investments in extra production capacity, I suspect. Eventually the 3.0 was replaced by the Mitsu 2.5 V6 which was mainly used in cars made by Mitsubishi. (I think the early cloud cars used it, too, probably because of its small size -- it fit.)

The 3.8 came when they needed more power than the 3.3 could muster, and wanted a premium engine ... so a long-stroke. Then the 3.5 was developed fresh, but with the same basics, as a very modern, powerful engine for the LH to show the new era. Eventually we got the revised 3.8 and the new 4.0 based on that family.

The 3.9 came, I think, before the 3.3, because they needed something with more power for the Dakota. It was a quickie, so to speak, there wasn't money for a new engine, so they cut two cylinders off the 360 (they used 'em later to make truck V10s.)

Then the 3.7 was designed as a truck engine, off the 4.7 model, to replace the 3.9.

Now, the 3.6 came in for SUVs and minivans and was used in cars as well; it's a good general purpose engine, it seems, with different tuning and some internal parts changes for various adaptations, e.g. Wrangler and Ram. But they need something smaller and lighter and more fuel efficient for Cherokee, and the 3.2 was born; it is also good for the cars and will probably replace the 3.6 in some applications, because it provides most of the power with better mileage.

Then, again, the 3.0 is designed for Europe.

That isii the high level overview of my understanding of the situation. If you want a lot more detail, get the Weertman book. http://www.allpar.com/reviews/other/engines.html
 
#20 ·
Bob_Sheaves said:
Applications are exclusive. You cannot optimize one design for all purposes. The more highly tuned, the narrower the operating range (note I am NOT saying rpm or power or torque-this is far more detailed than I am willing to spend time explaining now) and the less flexible the resulting engine is. There are "things" done to an economy engine that will cause MASSIVE warranty claims in a truck.

No one at Chrysler Engineering is that stupid to misapply an engine with that kind of issue.
i can understand that logic, especially when it comes to the 3.6L.

Nonetheless, i still have a question:
What does the 3.2L V6 accomplish that the 3.0L V6 can't accomplish?

i know the old saying, "there is no replacement for displacement." But can .2L make that much of a difference to a given application?
 
#21 ·
Bob_Sheaves said:
Do you honestly think displacement is the only distinguishing feature?
No no. I've been here way too long to make that kind of assumption :). And that is what is so fascinating about this kind of stuff! What makes little sense to a lay person makes all the sense in the world to an engineer. I have no doubt in my mind that Chrysler needs a 3.0l and a 3.2l. the reasons go beyond my current understanding and (I can admit that). That said, I have some reading to do...
 
#22 ·
DaveAdmin said:
This time, it's a large number of specific applications of a single engine family.

Last time, let's see:

LH family (so named, but the 3.3 came before the LH) -- 3.3, 3.5, 3.8, 4.0
"AMC" truck engine -- 3.7
"6/8 of a 360 V8" engine -- 3.9
MMC 3.0 and 2.5

Why?

Well... first came the Mitsu 3.0. Chrysler was going to buy all of Mitsubishi, so that made sense -- their future division made an engine that they needed, so they bought it for the few vehicles that really needed them. As time went on, it must have dawned on people that they could build something better suited to their needs, cheaper, and that fuel would not be getting scarce again any time soon, so V6 demand would stay.

So then the 3.3 was born. It met their power needs, sitting above the 3.0, and complementing it. They still bought the 3.0, partly to avoid investments in extra production capacity, I suspect. Eventually the 3.0 was replaced by the Mitsu 2.5 V6 which was mainly used in cars made by Mitsubishi. (I think the early cloud cars used it, too, probably because of its small size -- it fit.)

The 3.8 came when they needed more power than the 3.3 could muster, and wanted a premium engine ... so a long-stroke. Then the 3.5 was developed fresh, but with the same basics, as a very modern, powerful engine for the LH to show the new era. Eventually we got the revised 3.8 and the new 4.0 based on that family.

The 3.9 came, I think, before the 3.3, because they needed something with more power for the Dakota. It was a quickie, so to speak, there wasn't money for a new engine, so they cut two cylinders off the 360 (they used 'em later to make truck V10s.)

Then the 3.7 was designed as a truck engine, off the 4.7 model, to replace the 3.9.

Now, the 3.6 came in for SUVs and minivans and was used in cars as well; it's a good general purpose engine, it seems, with different tuning and some internal parts changes for various adaptations, e.g. Wrangler and Ram. But they need something smaller and lighter and more fuel efficient for Cherokee, and the 3.2 was born; it is also good for the cars and will probably replace the 3.6 in some applications, because it provides most of the power with better mileage.

Then, again, the 3.0 is designed for Europe.

That isii the high level overview of my understanding of the situation. If you want a lot more detail, get the Weertman book. http://www.allpar.com/reviews/other/engines.html
Dont forget the 2.7/3.2 family.... those lovely Benz derived motors... or at least thats where I told their origins were.
 
#23 ·
Danno said:
Dont forget the 2.7/3.2 family.... those lovely Benz derived motors... or at least thats where I told their origins were.
The 1998 3.2L came from the 1993-97 3.5L. Far as I know, some of the main changes were aluminum block, smaller bore, higher compression, and interference valvetrain. They began boring out the 3.2L to a 3.5L in 2000(?) and eventually stroked the 3.5L to a 4.0L for some vehicles. I think when Dave said "Eventually we got the revised 3.8 and the new 4.0 based on that family.", he meant the revised 3.5. The 2.7L came out at about the same time as the 3.2L, but has a timing chain and DOHC as opposed to the 3.2/3.5/4.0's timing belt and SOHC. They're all Chrysler designs, though; no Daimler in their history.

Back on topic, I wonder if the 3.0 MultiAir2 will ever be brought to North America, or if it will always be a Europe-only engine?
 
#24 ·
fenderbass said:
i can understand that logic, especially when it comes to the 3.6L.

Nonetheless, i still have a question:
What does the 3.2L V6 accomplish that the 3.0L V6 can't accomplish?

i know the old saying, "there is no replacement for displacement." But can .2L make that much of a difference to a given application?
 
#25 ·
DaveAdmin said:
The 3.9 came, I think, before the 3.3, because they needed something with more power for the Dakota. It was a quickie, so to speak, there wasn't money for a new engine, so they cut two cylinders off the 360 (they used 'em later to make truck V10s.)
:lol:
 
#26 ·
I typed too fast, and thanks for catching that, UN4...

Re the 3.2 vs the 3.0...

I believe the 3.2 will cost less to make than the 3.0, and be faster to develop and produce.

The 3.0 has to have a stronger block, and the added efficiency tricks (MA2, DI) are not cheap, nor are they fast to get to market.

In the US, the 3.2 will be fine. The slight displacement increase will help with power over a 3.0. It will arrive in time for Cherokee and it will cost less to build which is important.

In the EU, the 3.0 is needed because fuel costs trump vehicle costs, especially for luxury engines (just about any petrol V6).
 
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