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Discussion Starter · #1 ·
i bought a cherokee and every one tellls me that 2.8ls suck at climbing. is this true? if so what can i do to soup her up. i have a 3" lift already. please help. i am just begining
 

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Get a 3.1 litre out of a Camaro......Same bolt pattern as the 2.8
GM also sells a 3.4 litre long block as a replacement for the 2.8...
Other than that... keep the engine tuned up and keep the truck as light as possible.
 

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The 2.8L V6 is pretty gutless, so when that thing dies, i'd swap in something newer and more powerful. A 91 or newer High output I6 4.0L, or what chris also mentioned are good swaps that are somewhat fairly bolt in. New gears would also help, but i'd think future as far as they go, meaning, are you going to swap out the axles? You live in Utah, theres tons of places down there that should be able to help you.
Jordan
 

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As for the Camaro motor.. you will be looking in around an 85-89 kind of era....they did make a Multi-point fuel injected version of this engine but you had better be into electronics/electrical work if you plan on splicing the FI into the Jeep harness.
As for other sources of info on 2.8 performance (an oxymoron....)
try seeking out Chev S-10 truck websites (even lowrider street truck kinda places....they were blessed with the 2.8 engine too....)

Finally I think that Jeep redesigned the firewall and front clip on the XJ when they went to the 4.0 engine.... I don't think the I-6 will just drop in place of the 2.8......
 

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The front grill assembly, radiator, and just about everything else in the engine compartment is different between the 2.8L/2.5L and the 4.0L. Plus the 2.8L has a different tranny bolt pattern than the 4.0L block. The 2.8L bolt pattern is identical to the 2.5L though.

--Pete M
 

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Discussion Starter · #7 ·
hmm

so my best bet is the camaro? if it has the same bolt patern then it should fit. but is the l6 4.0 even am option. i mean will it even go in?
well thanks for the info its a real help.
do any of u have any gear ratio suggestions? for cherokee.
 

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The 4.0L will not fit unless you replace much of the front clip with parts from a 4.0 equipped XJ. The block is quite a bit longer than a v6. Besides, it won't bolt to your tranny anyway.
I did a breakdown of interchangablility in chevy engine years as sorted using car-part.com. The search was for a Camaro v6 engine of each year. The Firebird's results would be the same.

93-95 - 3.4L
91-92 - 3.1L
90 - 3.1L
89-90 - 2.8L
88-89 - 2.8L
87 - 2.8L
85-86 - 2.8L

Unfortunately Car-part doen't say *WHY* the years are different from each other. If you had a '90 Camaro and wanted a direct swap of the *entire* engine assembly, then '90 is the only year. The change could be a major as adding fuel injection or as minor as an emmissions tweak. (Searching for just the engine block reveils that the '90 - '92 are indeed interchangable blocks.)

I also just found a website that deal only with the chevy v6s.
http://www.60degreev6.com/
He seems to be in the process of revamping the website, so not all the links work perfectly, but there is some awesome info there for everyone wanting power from their 2.8L equipped Jeep.

As to gear ratio, that depends on the size tire you'll be running, whether you have an auto or manual trans, and how much offroading you'll be doing relative to highway travel.

--Pete

P.S. Want to know something weird? Searching for a 1990 Camaro engine block (meaning *just* the block) brings up the Isuzu Rodeo!
 

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FYI: i've compared XJ and MJ engine compartments with and without engines. the front clip, rad support, and firewall are the same. for the 2.5 and 2.8 the rad sits a little ways behind the rad support, for the I6 the rad snugs right into the rad support. difference would be different rad and rad brackets. all the same=less tooling=less money spent=more profit=what car company wants, makes sence to me
 

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I think one of the members of this board, Dan, swapped a 4.0L into a 2.8L XJ before. You might want to contact him and ask.

...lars



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The 2.5L and 2.8L compartments are, for all intensive purposes, identical. AMC only made one set of engine compartment pieces for both engines to share. But when the 4.0L came around in '87, the new engine required several changes to make it work in the XJ and MJ. One necessity was allowing for the really long radiator needed to soak up the larger amount of excess heat. I can't say for absolute certain, but I'll bet the 2.5Ls kept their compartment layout for at least several years afterward, because the factory already had the stamps and molds for it.
I'm not saying that it's impossible to throw a 4.0 into a 2.8 equipped vehicle (as long as there's a tranny swap involved). But I own an '86 2.8L Comanche and an '88 4.0L Comanche and their radiator support areas are VERY different. If I tried to put the 4.0L radiator into my '86, the core would overlap on either side with metal from the radiator support. I imagine a different sized radiator could be put in to fit the space available and might work just fine. Make sure it's a high quality one though.
The Chevy 60* v6s bolt to the 2.8/2.5 tranny, bolt to the motor mounts, and the later years produce a respectable amount of power. It's mostly the Gen 1 Chevy blocks that are known for power and reliability deficiencies.

--Pete

P.S. The 4.0L swap still requires a tranny that will bolt up to your new block and that tranny needs to match your transfercase's spline input.
 

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the only side by side comparison ive done was my old '85 Cherokee 4cyl parked next to Dan Brahma's early 90's(91?) 4.0 Cherokee. as far as we could tell the only difference was bolt on peices to tuck the 4.0 rad into the rad support. factory does do weird things though
 

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Discussion Starter · #13 ·
well

ok this is great information. but i will have to find someone who is a machanic before i can do anything. is fuel ejection any better than carberated or is it even worth changing? cause my friend james told me that carberated engines have a hard time starting up when the die on a hill? so should i buy the kit the converts it to fuel injection or is it a waste of time?
 

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You should contact Jeep Love on this board. He's got a 2.8L. Edlebrock manifold, big4 barrel carb, cam and duel exhaust. Got quite a bit of jam compared to stock. He's upgrading to fuel injection from a camaro....... I'll let him know about this post.
 

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Personally, modifying it is going to be MUCH more expensive than just selling it and buying a 4.0l model. You'll have to replace the front clip, motor mounts, buy an engine, figure out the fuel injection, buy a computer to manage the FI, probably replace your tranny (I think you have the 999, which probably won't bolt up to a 4.0L). Plus, you're stuck with the options presented earlier...3.x litre is still not enough power for the XJ in my opinion. The cool trick would be to swap in a Chevy V8 using a TH350 or 400, but then you're going to have to figure out what to do for a transfercase that will bolt to the output and have a left side output on the front shaft.

Anyway, back to my original comment. You can pretty much do anything you want to with the thing, but it's going to cost you several thousand dollars at a minimum. Considering you can buy a 4.0L equipped XJ for only a couple hundred more than what you can sell yours for, you're about to learn all about the law of diminishing returns. Just drive it, shop for a 4.0L, then sell it when you can get the most for it (maybe spend a day detailing the inside and cleaning the engine compartment...THAT will give you a return on your time investment...swapping engines won't).

Anyway, take it for what it's worth. I've owned 4 XJs...but only the first one had the 2.5L. I learned quickly that it'd be WAY cheaper to sell it and buy a 4.0L, so that's what I did. You'll love the 4.0L engine...it makes good torque, good power, and will run forever (nearly).

Oh, not to be a wanker, but you spelled "chief" wrong in your user name. "I before E except after C".
 
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