Need Good v-8 conversion for xj

[Rand McNally]

Ya'll are seriously f$@cked! I agree that the 4.0 makes plenty of power for rocks: with the right gearing; however, how many of us live in Utah? I live in Louisiana and wheel in Texas and Arkansas. Alot of mud with the rocks=wheel spin and horsepower. I can build a mild small block Chevy V-8 for much less than a "stroker" 4.0 with alot more power. Quit stomping on other peoples ideas based on brand loyalty! We're all building rigs to enjoy the wilderness; don't slam somebody's idea for getting there.

You're missing the point. Nobody is talking about the cost of building a stroker over the cost of building a V8. The cost comes in INSTALLING the V8. You need to do A LOT of research before attempting this project. A buddy of mine but a RamJet 350 in his YJ and the project has become a full time job of over a year. He spends about 6-8 hours a night in his garage (shack) working on this thing. This equates to A LOT of man hours and A LOT of money. Last time I heard he is well over the $20K mark of total cost. Not to mention you need to be a damn good fabricator. Even using a kit there is a lot of fabrication involved. Getting the bugs worked out is also a really big issue. Every time he starts it there is another problem. Tranny issues, transfer case issues, drive shaft issues, axle issues, electrical issues, ect. It isn't a simple install. Auto engineers get paid good money for what they do. When you go tampering with that there is always problems. I am not trying to discourage you, but it sounds like you are a little ignorant as far as what it is going to take. My buddy did the V8 because like you, here in MN there is a lot more mud than rocks. Fotunately for him, his YJ is a toy and something that doesn't have to run everyday and something he can throw money at when he wants to. Unfortunately for him, by the time he gets it running, we will all be too old to enjoy it... When/if my 4.0 dies, I am going to look into swapping a V8. But now that I know all the issues, it will definately not be weekend project.

 

[XJEEPER]

Hmmm, interesting thread. Having swapped a few motors/trannys before, the nail has been hit on the head. The cost of the motor (350 V8 vs stroked 4.0) is only part of the expense....many minor items add up to big $$$.......as for time, it takes what it takes.

If the rig is not your DD and you have plenty of time to iron out all the custom stuff that will need to be addressed as well as the fab skills/tools to build your own mods or the deep pockets to pay someone else then I say, go for it. I'll take a SB 350 anyday over the 4.0 for power, but with 195K on my 89, I can't much complain about the power and longevity and I still get 15-19 mpg out of it.

Not sure the advice is being conveyed properly, but as Rand indicated.....know what your getting into before you jump. If you decide to go with a new 4.0 longblock, I'd suggest Jasper motors or similar with a warranty that is real. If not them snag a late model donor 4.0, add a cam, header and bored TB and tweak all the power you can out of it.

 

[DrMoab]

One thing I am really suprised no one has broght up...Thats the cooling issue with XJs and V8s The way the grill is shaped its almost impossable to get a V8 to cool correctly. In fact the 4.0L moters have a hard enough time as it is.
So if you are doing a V8 conversion better tack on another 500-800 bucks for a good aluminum radiator and even then you might run into troubles.

 

[Eagle]

Quit stomping on other peoples ideas based on brand loyalty! We're all building rigs to enjoy the wilderness; don't slam somebody's idea for getting there.

I don't think anyone is beating on the guy because of brand loyalty. They're beating on him because he is predicating his V8 swap on the statement that the Jeep 4.0L engine is "junk" and doesn't make any power ... and we all know that's simply not true. If he would just come right out and admit that he wants a V8 because he wants a V8 he'd probably get a much better reception around here. As it is, he started off making himself look like an idiot, and has been digging the hole deeper with every post.

One thing I am really suprised no one has broght up...Thats the cooling issue with XJs and V8s The way the grill is shaped its almost impossable to get a V8 to cool correctly. In fact the 4.0L moters have a hard enough time as it is.
So if you are doing a V8 conversion better tack on another 500-800 bucks for a good aluminum radiator and even then you might run into troubles.

Good point. A friend in RI has (or had ... I think he finally sold it) an XJ with a nice SBC conversion in it. He bought it like that at an auction, but the installation was done pretty well. It sounds sweet, but it eats rear axles. And, yes ... it doesn't like to be run at less than highway speeds. We hate to see it show up for trail rides, because we're constantly having to take breaks while Charlie lets his heap cool down.

 

[Lawn Cher']

I've been pondering a GM 6.2 diesel swap into my '87 MJ longbed... if it'll fit. Judging by the 6.5 in my Suburban it will be close. Thinking 700R4 and 231. Already have D44 and 3.55 gears, 31" tires. I expect around 30 mpg.

 

[red91]

I've been pondering a GM 6.2 diesel swap into my '87 MJ longbed... if it'll fit. Judging by the 6.5 in my Suburban it will be close. Thinking 700R4 and 231. Already have D44 and 3.55 gears, 31" tires. I expect around 30 mpg.

hope your 6.2 is a rebuild, those are notorious for ___________ !

 

[Lawn Cher']

Like anything on the internet, notoriety is often blown out of proportion. The 6.2/6.5 is a decent engine (no Cummins, but it doesn't cost as much either.) When cared for by a conscientious owner, it will last. And it has its quirks, but what doesn't? Believe it or not, is not the only haven of sound automotive tech. I have learned alot about the reliable 6.5 in my Suburban at www.gm-diesel.com and www.dieselplace.com, which has led me to the conclusion that a simple 6.2 would be a decent candidate for my MJ.

 

[sbxoxj]

gm diesels suck except 4 the 6.6 driven both 6.2 and 6.5 the duramax is the only good one. the 6.5 is decent. go cummins already looked at that option myself.

 

[Lawn Cher']

gm diesels suck except 4 the 6.6 driven both 6.2 and 6.5 the duramax is the only good one. the 6.5 is decent. go cummins already looked at that option myself.

See what I mean? You are comparing apples to oranges here, dude.

 

[Darky]

drove a 6.2 Suburban, and while it wasn't fast, not even slightly, it drove good, I found no problem with it. The only thing I noticed was a slight whine when I stepped on the gas real hard. It was sold before I could get money, and the guy seems to enjoy it.

 

[Lawn Cher']

drove a 6.2 Suburban, and while it wasn't fast, not even slightly, it drove good, I found no problem with it. The only thing I noticed was a slight whine when I stepped on the gas real hard. It was sold before I could get money, and the guy seems to enjoy it.

The 6.2 is normally aspirated (and is very miserly on fuel,) while the 6.5 is turbocharged, which makes a big difference in pulling power. (My 6.5 Sub' has plenty of go, and I haven't modded it yet.) But I figure that taking that 6.2 and putting it into a MJ that weighs at least 2500 lbs less than a Suburban should make for a decent match.

 

[Darky]

And Banks makes a Stinger package, complete with turbo and manifold, for the 6.2. Supposed to add some 200+ hp as well as about equal torque. The Suburban I looked at is supposed to get 21 highway, which is better than I usually see in my XJ.

 

[Lawn Cher']

And Banks makes a Stinger package, complete with turbo and manifold, for the 6.2. Supposed to add some 200+ hp as well as about equal torque. The Suburban I looked at is supposed to get 21 highway, which is better than I usually see in my XJ.

I average about 16 with mixed city highway driving, but on long interestate road trips I can get 21 or 22. It is very speed sensitive, as in anything over 65 or 70 and economy drops off quickly. CD on a big brick is high, and it is a square function of speed. That, and anything much over 2k rpm and it gets kinda noisy, but that's what the 10 speaker stereo is for. Honestly, my tire noise is more annoying than the engine.

 

[jeeppowermj]

Im not trying to be an ass, but you did come onto a JEEP forum and ask a question about swapping out a great motor for another lesser motor. Also I'll quote you on this one "any help with sites or stores would be greatly appreciated". You can't ask for any help and then not accept peoples comments. Maybe you should have said "I only want help from people who think replacing the 4.0 is a good idea." I guarantee that you wouldn't have gotten so many replies then.

 

[xjextreme]

You must be the part of the U.S. that other countries hate. Just so you know, I hate glasspacks (few people have them in Texas), I prefer the sound of Magnaflows. You're just jealous because you don't live here.[QUOTE/]
BOOYA!!!!!
I also am trying to put a v-8 in my xj not because i don't like the 4.0, i do, but my xj has the 2.5ltr. 4- banger with two hole the size of silver dollers! After doing some research, I found it would be in MY best interest to do the swap. Junk yards around here want to much $$$ for the 2.5 & 4.0, so in MY case it is cheaper in the long run to do the swap. I can also get the tranny and t-case and still come out cheaper. TO EACH HIS OWN!

 

[xjextreme]

oopps!!!

Don't Know How This Got Here???????? Wrong Forum Sorry

 

[Darky]

Re: oopps!!!

A Chevy 350 isn't exactly a lesser motor in comparison to the 4.0. I'd love a V8, but I'd hate the mileage and I can't afford to have my XJ off the road for that long. I'm just jealous that a V8 or stroker swap isn't in the cards for me anytime soon...

 

[renegade_z71]

a cheap way to go and get good power cheap is to buy/ build a vortec 350, use a gm performance intake and run a tbi setup like what was used in 88-95 chevy trucks. im my old z71 i ran that with 33' tires and 3.73 gears and it pulled great had lots of power and still managed around 16-17 mpg when i was driving it hard. for a heavy truck like mine it had more than enough torque to run hard in 4wd and still have a good top end when i was on the highway. with an xj being alot lighter this could be an ideal setup. the 350 is a incredibly reliable power plant with lots of after market. the hp tq quotes from a dynoed setup is 290hp/385lbs from a stock l31 vortec motor running a tbi set up in stock trim.

 

[jamboree]

i was thinkin about doin this swap to for a few reasons.. I have a v8 laying in my garage and its alot cheaper than stroker a v6. chevy motors can be picked up for almost nothing now a days. the only problem i see is getting it to fit in there unless your good with cars and know what your doing. if not itll be cheaper to get a stroker 4.0. ive swapped a v8 into trucks the same size as xj's and theres 2 big problems, the engine is longer so you will have a hard time fitting a radiator and a fan also its wider so headers will come close to the steering shaft and make it hard to run an exhaust. so unless you have the tools to fabricate or know someone who can the stroked 4.0 seems like a better idea. once mine blows up im gonna try the swap only because i have a 350 out of my camaro layin in my garage collecting dust. just my 2cents

 

[MJ_Chubs]

jamboree-The SBC is shorter than the 4.0. There is more room in the radiator area. Through the use of block hugger headers or AA swap manifolds, exhaust really isn't an issue. As was mentioned before, cooling is the major issue with this swap. I would be curious to see what types of small steps to help cooling (like hood vents, ceramic-coating on exhaust, etc.) would do to aid cooling.