Pentastar engine - Page 7 - JeepForum.com

Reply
 
LinkBack Thread Tools
post #91 of 126 Old 12-20-2011, 04:59 PM
Mictrik
Registered User
2004 TJ Wrangler 
 
Join Date: Jun 2010
Location: USA
Posts: 49
Quote:
Originally Posted by Fellows View Post
I totally agree with the exception of the current Chrysler not having a hemispherical design. When this engine came back out, there were countless cutaway models at carshows and in magazine's showing the hemispherical looking head. I'm not sure if its exactly the same dimensions as the originals, but it definately had the valve on each side requirement along with the giant, overweight looking head.
It is not a true hemispherical cylinder more of a triangular head. Little advantage to it, other than gimmick and using their "Hemi" trademark in my opinion. Multi-valve heads & oblong or other shaped heads designed to cause currents in the chamber to better mix the fuel into a combustible gas have really made the hemispherical chamber especially in its two valve incarnation, obsolete. My bet is that Chryslers present design uses two spark plugs as a way of keeping a somewhat kind of hemispherical head while reducing hydrocarbon emissions. A feat better accomplished with 4 valves head shaped to further facilitate atomization. You see they trade marked that name "Hemi" and they want the most out of it. The HEMI design even when it had more merit was never a great choice for the Wrangler. The design requires way too much engine bay space due to the need for thick convex shape outside cylinder heads and the more complex valve linking to accommodate the odd valve stem angles. The design is wasteful in terms of fuel, and large relative to power output; two things we do not need in an off road vehicle. An off road power-plant should be efficient, simple, and reliable; for me this means a Diesel...

In a race engine that produces its peak torque & HP at relatively high RPM and before 4 valve heads & other performance efficiency methods were commonly applied, the cross flow ability of the hemispherical design provided more value. So in certain applications, given certain constraints the design has merit but just not for Wrangler. That is unless the driver just likes the trademark "HEMI" stamped on their Jeep.

Mictrik is offline  
Sponsored Links
Advertisement
 
post #92 of 126 Old 12-20-2011, 06:09 PM
OutlawJK
Registered User
 
Join Date: Aug 2011
Location: artesia
Posts: 19
Could you imagine having to listen to that rattling diesel engine all day !!

I own a Dodge with the cummins engine and love it
It's a 2500 4wd and it gets great mileage

But I like the 3.6 in my jeep with the top off
Not having to hear the constant rattle
And smell the fumes of a diesel
OutlawJK is offline  
post #93 of 126 Old 12-21-2011, 12:52 AM
Mictrik
Registered User
2004 TJ Wrangler 
 
Join Date: Jun 2010
Location: USA
Posts: 49
Quote:
Originally Posted by OutlawJK View Post
Could you imagine having to listen to that rattling diesel engine all day !!

I own a Dodge with the cummins engine and love it
It's a 2500 4wd and it gets great mileage

But I like the 3.6 in my jeep with the top off
Not having to hear the constant rattle
And smell the fumes of a diesel
Well, if off road for you is just a few miles going over obstacles to see if you can, then any engine is fine but a Diesel is still better. If Off road is an African Safari vehicle, long distance traverse of tough terrain then a diesel is a must. And even you rock crawlers would appreciate the steady low end power. Many of your 4.0L sound like diesels once that tick gets pronounced...

In terms of noise, have you heard the 2.8l CRD in the Wrangler? You will smell more gas fumes on a cold 4.0l than diesel fuel on a CRD. It is not as loud as a Cummins. The Wrangler was never a good vehicle choice if a quiet ride is what your after, road noise is probably louder than any Diesel. The 3.6L gets 10 MPG less than the Diesel with less torque where you want it. Bringing spare fuel is considerable more dangerous with gasoline as a fuel.
Mictrik is offline  
post #94 of 126 Old 12-22-2011, 03:26 PM
Matoskah
Registered User
2012 JK Wrangler 
 
Join Date: Dec 2011
Location: Bossier
Posts: 183
Is the 2012 a "Flex Fuel" engine???????
Matoskah is offline  
post #95 of 126 Old 12-22-2011, 03:27 PM
Fellstar
Registered User
2012 JK Wrangler 
 
Join Date: Oct 2011
Location: Merrillville
Posts: 600
Quote:
Originally Posted by Matoskah View Post
Is the 2012 a "Flex Fuel" engine???????
No.
Fellstar is offline  
post #96 of 126 Old 12-22-2011, 03:58 PM
vincejeep1
Registered User
2010 JK Wrangler 
 
Join Date: Feb 2009
Location: Hobart
Posts: 336
The new diesel engines have to have a Diesel particulate filter and it has to be serviced if you don't service it or ignore the service engine light then once it gets shut off it wont restart and has to be towed to a dealer and serviced,reprogrammed before it will start . This is also what happens on 2010 and newer semi trucks
vincejeep1 is offline  
post #97 of 126 Old 12-22-2011, 04:16 PM
Mictrik
Registered User
2004 TJ Wrangler 
 
Join Date: Jun 2010
Location: USA
Posts: 49
Quote:
Originally Posted by vincejeep1 View Post
The new diesel engines have to have a Diesel particulate filter and it has to be serviced if you don't service it or ignore the service engine light then once it gets shut off it wont restart and has to be towed to a dealer and serviced,reprogrammed before it will start . This is also what happens on 2010 and newer semi trucks

Is this a problem, Do they fail or introduce complexity? I am all for environmental preservation but if this were to become an issue for an expedition vehicle I am sure there will be a workaround. One needs reliability for off road travel, the complexity added to modern engines is often of negative value.
Mictrik is offline  
post #98 of 126 Old 12-24-2011, 01:52 PM
tommy35SS
Registered User
2008 JK Wrangler 
 
Join Date: Dec 2009
Location: Texas City, TX
Posts: 67
A diesel Wrangler might be closer to being a possibility if Jeep follows through on this
http://www.leftlanenews.com/diesel-p...-vehicles.html

Hopefully they pair it with this
http://wot.motortrend.com/we-hear-8-...-6-123839.html

This would be the 1-2 punch to show America what we're missing out on due to some stupid stigma of crappy designed GM diesels from the early 80's, heard they didn't even come with a fuel filter/water separator on them. You could ask any mechanic and he'll tell they did not build those cars right

2008 JKUR 6 speed-1.5" TF coil lvl kit, 285/70-R17 MT/R's, Staun BL's, RIPP Longtubes
tommy35SS is offline  
post #99 of 126 Old 12-24-2011, 03:10 PM
Mictrik
Registered User
2004 TJ Wrangler 
 
Join Date: Jun 2010
Location: USA
Posts: 49
Quote:
Originally Posted by tommy35SS View Post
A diesel Wrangler might be closer to being a possibility if Jeep follows through on this
http://www.leftlanenews.com/diesel-p...-vehicles.html

Hopefully they pair it with this
http://wot.motortrend.com/we-hear-8-...-6-123839.html

This would be the 1-2 punch to show America what we're missing out on due to some stupid stigma of crappy designed GM diesels from the early 80's, heard they didn't even come with a fuel filter/water separator on them. You could ask any mechanic and he'll tell they did not build those cars right
Well, I hope so as I would like to have the option of a 4 door wrangler Rubicon with a Diesel & strong Auto or Manual transmission.
Mictrik is offline  
post #100 of 126 Old 12-24-2011, 04:02 PM
JKRazz
Registered User
2012 JK Wrangler 
 
Join Date: Dec 2011
Location: Broken Arrow
Posts: 1
I have a 2012 JK Unlimited Rubicon with the new 3.6 Pentastar...all I can say is "WOW"! It is a serious improvement and can't be called anything less than needed in the JK Unlimited. It had got a ton of power and is got it at all speeds.
JKRazz is offline  
post #101 of 126 Old 12-24-2011, 04:23 PM
Panhead5
Registered User
2009 JK Wrangler 
 
Join Date: Sep 2011
Location: Columbus,Ohio
Posts: 198
The pentastar is a big improvement over the 3.8 but I would not hold my breath for diesels.This country is so diesel unfriendly right now and most folks idea of a diesel and the realities of the modern emissions choked/strapped diesels are a far cry apart.
Panhead5 is offline  
post #102 of 126 Old 12-25-2011, 04:37 PM
Mictrik
Registered User
2004 TJ Wrangler 
 
Join Date: Jun 2010
Location: USA
Posts: 49
Quote:
Originally Posted by Panhead5 View Post
The pentastar is a big improvement over the 3.8 but I would not hold my breath for diesels.This country is so diesel unfriendly right now and most folks idea of a diesel and the realities of the modern emissions choked/strapped diesels are a far cry apart.
No Diesel no Jeep for me, and if the Diesel is indeed so "choked" I again will not purchase one. I really liked the the model offered in Europe. When I wish to have one I will either buy an older stock Rubicon model and install a 2.8 Diesel as parts are available or I will simply get an older Defender. I find it strange how the best off road vehicles are not available state side. The Defender and the real Toyota FJ's are not sold in the States. The FJ cruiser is not in the same class as the others.
Mictrik is offline  
post #103 of 126 Old 12-25-2011, 05:12 PM
dwink
Registered User
2012 JK Wrangler 
 
Join Date: May 2009
Location: Lake Tahoe
Posts: 290
I just traded in a BMW 335d on my Jeep. I loved the powertrain on the BIMMER 3.0 Liter twin turbo diesel with 265 HP and 425 pound feet.

It also revved pretty good for a diesel, although I can say that I enjoy revving the pentastar, I missed that with the BMW (although my 911 still cures the itch best!!).

I miss the swell of torque that the BMW produced, and it would be a great compliment to the Rubicon if Jeep was able to design a similarly good diesel powertrain.

The BMW would see 29 MPG in the city regularly and I once got 43 MPG from Reno to Vegas - and I was going 80 most of that trip. It is a 3900 pound sedan so the Jeep would be almost the same weight....

I would certainly consider a Wrangler Diesel if it were like that...

2012 Wrangler Rubicon- OME 2.5 HD lift, adjustable lower control arms, Adjustable sway bar links, AEV rear bumper/carrier, Rugged Ridge XHD front, Hella Rallylight upgrade, MORE skids, 315/70 DuraTracs on stock wheels for the winter, working on my summer setup.



Retired.... but a good friend still has her! 1990 YJ 3" Trailmaster 258 Jasper re-manufactured engine. Nuttered. Webbered (38). Team Rushed. Headers. Cancel that Webbered- went to a Howell FI setup.
dwink is offline  
post #104 of 126 Old 12-25-2011, 05:59 PM
tolnep
Registered User
 
Join Date: Jul 2004
Location: on the farm
Posts: 33
you will not be allowed to buy a diesel jeep. our minders in the congress have rightly assumed that they know whats best for us and that diesel poisons the children. so no diesel jk, no diesel toyota, no diesel bmw 130d.

and if they do decide to allow those here, they will raise the price of diesel so much that no one will buy these cars.

every year the government gets better at protecting us from ourselves. and taxes us more to enable them to do so.
tolnep is offline  
post #105 of 126 Old 12-25-2011, 07:18 PM
i82much
Registered User
 
Join Date: Mar 2009
Location: MD
Posts: 129
I get that a diesel would have greater range. However, I find strange comfort in knowing with a gas motor I can run down the battery on a freezing cold day, add some starting fluid and have a decent chance of pop-starting that bad boy.

As I recall, in the old days you didn't need any electrical power at all for a diesel since they didn't have an ignition and used a mechanical fuel pump. I don't know for sure (lazy googler) but I have to doubt that's the case anymore.
i82much is offline  
Reply

Tags
JK Wrangler , pentastar engine , rumors , speculation , thoughts , wrangler

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Engine code p1281, engine cold for too long....which temperature thermostat to use? ShadowLawz TJ Wrangler Technical Forum 11 11-25-2014 11:23 AM
........ Buy 2010 or wait for 2011 with new engine Pentastar V6 ???? jeep81 JK Wrangler Technical Forum 59 01-31-2010 05:49 PM
Has anyone done this "Pentastar Club?" CTJeepGuy JK Wrangler Technical Forum 18 12-04-2009 06:30 PM
No Wrangler Pentastar? ARTSBEST Wrangler General Discussion 12 04-10-2009 01:57 PM
Check engine light and engine sthal after cleaning battery posts AirborneSilva TJ Wrangler Technical Forum 4 05-26-2003 11:43 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome