2.5L Jeep Internal Pics Part 2

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Had an extra day waiting on parts so decided to really clean the valves, CC's, ports etc... Added new valve stem seals as well. Fired her up a little bit ago and she's purring smooth with no more exhaust leak!!

New Valve Stem Seals.....

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Cleaned Cylinder Pics

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Cleaned Piston Closeup

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Under the cover valvetrain going back in

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Devalved Head CC's and Ports Cleaned

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Cleaned Head Ports

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Cleaned Valves 1

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Cleaned Valves 2

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Ryan00TJ,
Nice job on the head! It looks good.
You know, the 2.5L is an awesome Jeep engine. The head comes off in like 20 min and it's easy to work on. Try that with a 2.4L.

Take it easy.
 
These are the last of the simple,cast iron motors . Even though they are inefficient they are fun to work on and tough as nails if good materials are used up front.Both my 4.0L Jeep engines seem to be as sensitive to abuse as an anvil
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Greaser
Member # 1027 posted December 01, 2005 08:12 PM
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"Even though they are inefficient"

Why are 2.5L's inefficient? My YJ always has awesome emissions reports and still gets 16-18MPG highway pushing 35's.

The new TJ's with the 2.4L are no more efficient than a 2.5L, 18city/20highway. DMC used the 2.4L Neon engine because it's used in more vehicles and cuts costs. They stuck a DOHC car engine in a truck. To me, that's inefficient.
 
Well, I can get a lot more fuel economy out of a like displacement V-alum/iron hybrid then I can out of the 2.5 or 4.0. My wife's 4.0 w/5-speed can MAYBE get 20 if you're on a longer trip and keep it around 65 or lower. The best mileage is between 45-50. In a Cherokee it's better. My 2.5 (auto) with stock small tires got 21.x on a relaxed 4 lane run of decent length ..but when speeds hit 65+/- ..the numbers dropped to 16.5 to 17.5. My Caravan with a 3.0 can almost break 25 mpg without regard to how fast I go ..70-75-80. Sure aerodynamic play a big part here ..but there's more to it then just that.

I would imagine in a sleeker/lighter chassis ..geared WAY high to take advantage of the lower torque curve, you could get some decent economy ..but you would be slower than a tug boat on drivability.

The 4.0 has a near diesel like torque curve. It's flat from about 1800-4000. That tells me that a good deal of your energy consumption is biased to the lower rpms. That is, there is a whole lot of inherent fuel consumption whether you want it or not. It's not capable of fuel squeezing. You could probably get the same fuel economy in a 5000lb chassis as you could with the 3200 lb TJ ..but you can't get any better, aerodynamics/gearing being equal, by going to a 2000 lb chassis.

I went to a Warn hub conversion ($1000 by the time I was done). It only yielded an inconsitant 1.5 mpg ..but you could feel a substantial "unloading" of having the front drive line not turning 24/7. Basically it made it feel better to consume about the same amount of fuel
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I had a 75 C20 with a 350-heavy 4speed with 3.73 gears that could achieve nearly 16mpg if I kept an egg between my foot and the gas pedal. It was only 2wd ..but weighed in at over 5700lb ..so the numbers just don't add up if it's was just displacement and aerodynamic involved here
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The 2.5 doesn't quite have the plateau like torque pattern of the 4.0. It's more jagged ..but still fairly low.

With an automatic (which I believe the 2.4 was only available with in 03 - a 6 speed was added later) the 2.4 gets like economy of a 2.5 auto. The difference is in performance. It's a revver ..the 2.5 is not. You get more "conventional" performance characteristics out of it ..as was mentioned.
 
"With an automatic (which I believe the 2.4 was only available with in 03 - a 6 speed was added later) the 2.4 gets like economy of a 2.5 auto. The difference is in performance. It's a revver ..the 2.5 is not. You get more "conventional" performance characteristics out of it ..as was mentioned."


The '03 TJ 2.4L's came with 5 speeds.
"Conventional" performance from a Jeep should be at the low end. The bottom line is : Car engines don't belong in Jeeps(Gary, you seem to be a Jeep guy, so I'm sure you agree).

**** is going to freeze over soon when they replace the 'ol 4.0L with soccer Mom's 3.7L...
4.0L = 235 ft/lb @1800
3.7L = 235 ft/lb @4000

Ryan00TJ, sorry we hijacked your post! Keep your 2.5L running pissah...
 
I prefer the 4.0 over the 3.7 but the 4.0 makes its peak torque at 3200 rpm.
 
The '03 TJ 2.4L's came with 5 speeds.

Are you SURE? When I went to build an 03 on the jeep site (I bought an 02) there was no option for trans. 42RE was the only avaible transmission according to the site. I've had many discussion on why it would be a challenge to swap the turbo hardware off of an SRT since it ONLY came with a 5 speed and the SE only with an automatic. This would make the swap impossible unless you could get the PCM modified with the vac/boost MAP fuel curves AND/or the software to run the transmission. I'd also wonder why they would come up with a 5 speed ..and then introduce a 6 speed 2 years later
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It would be practical if the 2.4 shared the 2.5 bolt pattern ..it would also make a 6 speed available for the 2.5 ...or maybe if the 6 speed will also fit the future replacement for the 4.0 to compensate for the wimpy torque of the 3.7
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i owned cherokees/wagoneers for 10 years. the 4.0 is a great engine. very tough and tourquey. the 2.5 was not too bad. the economy on mine was about 2 mpg better than the 4.0. that is with me having to beat the snot out of it to keep up with city traffic here in omaha. i had a 84 (first year) cherokee with the 2.8l chevy s-10 engine. what a hunk of crap. worst mileage and performance out of all of them. it went until 180k miles i finally sold it to a neighbor just to get rid of it.
 
Boy this sure is a hijacked thread
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I'm hoping that the get the diesel into the Wrangler without adding all kinds of accessories to ruin it otherwise. They need to get a stick for it too. Why in the eff they put it in a Liberty is beyond me. I'd give anything for a 25 mpg Wrangler. I don't care what cost analysis you go through. 18mpg vs. 25 mpg over the 10-14 years of ownership that I go through is worth it for a high torque and economical engine.

Why do they always put that which you most desire just out of your reach?? You can get a 2.4 ..but not the 2.4 with a turbo. You can get it in an SRT and a sissy PT ..but not a rough and tumble Wrangler. You can get a diesel ..but only in the Chevron Techron claymation commercial looking Liberty ..not in a Wrangler.
 
Gary Allan
Member # 409 - posted December 04, 2005 03:48 AM

"Why do they always put that which you most desire just out of your reach?? You can get a 2.4 ..but not the 2.4 with a turbo. You can get it in an SRT and a sissy PT ..but not a rough and tumble Wrangler. You can get a diesel ..but only in the Chevron Techron claymation commercial looking Liberty ..not in a Wrangler."

That's the way it is Gary! I guess for me, it wouldn't matter anyway, because I would void the warranty by trying to swap my SM420 into it. I'll stick with my "mostly" 1992 YJ and rebuild it every 10-12 years. Spring time will see a rear 9" and front high pinion D44. It's going to be pissah!!!

BTW, I'm sure Ryan00TJ doesn't mind the hijack. Maybe I can convince him to swap out his 5 speed junk and swap a Muncie SM420 in. I have an extra bellhousing kicking around...
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quote:

"Even though they are inefficient"

Why are 2.5L's inefficient? My YJ always has awesome emissions reports and still gets 16-18MPG highway pushing 35's.

The new TJ's with the 2.4L are no more efficient than a 2.5L, 18city/20highway.

My FULL SIZE 5000 lb truck with V8, 5sp, 4x4, ext cab, 6.5 foot bed gets 20 mpg highway with ease..

I'd say getting 16-18 mpg highway out of a 4 cyl is inefficient to say the least.
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I get 40+ mpg with my 4 cyl... (It's in a Corolla)
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Take care, Bill
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PS: Nice photos! Thanks for posting!!
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Don't worry about the thread guys. It's cool to see everyone's viewpoints. My TJ is setup w 4" lift 33" tires, lotsa heavy armor and skids. Lockers at both ends. It's a very heavy Jeep, well over 1000 lbs more than stock. Each of my Interco tires weighs 81lbs w the aluminum rim. I am running a 4.88 gear ratio to help out. The 2.5L is pretty underpowered compared to driving my brother's stock 98 4.0L TJ. It does have good lowend torque, but it hates to rev. I usually get 16-17 mpg cruising 65 on the highway and 18-20 mpg 55-60 driving. With the AC on @ 70 she sits on 12-14mpg. Heavy, Tent on 4 wheels = slow and bad MPG. It is a blast offroad though and holds its own very well.
When I need to go fast I always have my LS1 Camaro SS. It's a big difference driving the LS1 and then jumping in the TJ.

Zaedock, I'd take you up on the swap but future plans look to the 355ci SBC on my engine stand right now when the 4 popper finally goes. From the looks of things and the way she's running it might be a long time. A friend bought a 97 SE w the 2.5L @ 215K miles for a weekend and DD. It's now almost over 297K with no internals touched so I might be awhile on the swap.
 
"Why do they always put that which you most desire just out of your reach??"
If I were a Buddhist, I'd remind you that desire is the cause of all suffering, and say let go of your desire. Since these days I'm more of a masochist, I'll say because we're supposed to suffer....and like it.
"You can get a diesel ..but only in the Chevron Techron claymation commercial looking Liberty ..not in a Wrangler."
Liberty.I must go vomit now.
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Is it too much to hope for that DC will eventually come up with another inline-six for Jeep?
For that matter, is it in vain to imagine that they will ditch the Liberty and replace it with a less...gay looking vehicle?
I saw a Commander the other night and it looked alright, but I like 'em a bit smaller.
 
Btw- you know there's a AX15 swap for the AX5, don't you? The Dakota came with a 2.5 with the AX15. For some reason it's more complicated then one would think (I've lost the link) This should shift the weak link somewhere else
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Mark. If you're an Existentialist ..you can say "Now that I've truly suffered, I can now enjoy all things mediocre and mildly uncomfortable.
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Check this out :
http://www.jeeps-offroad.com/showthread.php?t=4740

I don't think the AX15 is worthwhile for a 4 cyl. It maybe stronger, but the gearing is just about the same. You might as well get stonger AND geared low.
Ryan, don't do the V8 swap!!! Everybody and their uncle does it. Save your .030 over for a drag car! My 7.05:1 1st gear is louder than my engine. People always ask,"what the h3ll is in that thing?" It's different and cool! BUT, if you really wanted a Chevy V8, with the SM420, all you need is a bellhousing and clutch component change.
...Ryan...SM420...swap...:subliminal message:

From Bill in Utah:
"I'd say getting 16-18 mpg highway out of a 4 cyl is inefficient to say the least."

Hey, Wild Bill, It may look bad, but trail Jeeps like mine and Ryan's weigh around 4K lbs, which is probably twice as much as your corolla. They're also about as aerodynamic as a brick and have a lot of parasitic loss from bigger trannies and t-cases to spin. Makes you wonder why they put a 4popper in to begin with.
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Oh well, at least it adds character and has good torque for the trail.
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I sat in a Commander at the Great American Jeep Rally (up here in New England) back in Sept. It was cool and reminded me of a big XJ. I like the 4.7LV8 too instead of the HEMI. Too many cylinder deactivation gizmos for me. My wife would probably get more tickets too.
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I kinda like the Liberty. I think the IFS stinks, but again, soccer Mom's are taking over! The 2.8L CRD isn't available here in Mass yet due to emissions. Soon, I hope.

Anyway, now I'm starting to ramble and will stop before I go on for hours. Build it, wheel it, fix it. That's it!

Happy Trails.
 
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