XJ V8 conversion

[alwayzAMC]

first off wanted to say hello, floated through here a few times, thought i would register and ask a few questions, and hope i can get some answers/ advice


it is time for another upgrade, i have an 87 XJ, it has 225,000 miles on it and the engine is just a little too tired to turn my 32's and it slows down on every hill it sees, i have a good line on a 305 chevy motor, what i am wondering is how much work is involved, and if anyone here has ever done this and what i might be looking at cost wise, i am not against the idea of a rebuild, but my wiring is in such an array, and my exhaust manifold is leaking, so either way i am looking at a medium cost factor any which way i look

 

[What Rd]

Chevy V8 conversions are workable, with a lot of work. There are a few guys on here running them. The first questions I would put to you are what type of use do you make of your XJ, and have you considered regearing the axles?

There are any number of alternatives open to you short of such a major custom undertaking. Which option will prove best for you will likely depend on how you use your Jeep and what you want to get out of it.

Almost forgot -
Welcome!

 

[alwayzAMC]

my intentions?? ramp her jump her beat her...

as of now it is a daily driver, and i use it in the woods as much as i can, it will stop being a daily driver as soon as i have enough spare time, good weather, and money to get my grand wagoneer roadable, i don't have any intention of re-gearing my axles, i do plan to tear them apart one day when i put in some air lockers, but until then they will stay sealed, and i like the way this is geared, just lacks a lot of push power at above 45 mph


is the 304 a direct bolt in, i could find one, then rebuild it as i get the last of life out of this engine, what i am after is some more HP, and some more torque, i know the I6 is good with torque, but won't ever do what a small block V8 can do, besides my other reality problem is the elictrical in my engine bay, there looks to have been an electrical fire in there at some point, and bare wires everywhere, i had to rewire my fuel pump, and distributer, and recently installed a starter switch so i didn't have to climb under it all the time to start it.

i am basically just throwing out ideas and trying to get some feedback so i can determine what route i am going to go

 

[Gecko]

If youre going small block, look into a duramax, my chevy friend and i have tossed around the idea. No real research into what tranny or work would need to be done, but its basically a great engine. Diesel will pull all day long, and with an extra grand you can get 500 hp and 700 lb-ft of torque pretty easy, and that will prolly rip apart any cherokee you put it in though. Well if you feel up to it, look into it and let the rest of us know about it.

 

[alwayzAMC]

if i were going to get a deisel i would drop it in my J-truck, and i want something i can rev high spin my tires and really throw some mud, so a gas V-8 is where i want to be,


anyone know if a 304 will bolt up to an auto tranny??

 

[crimsonride]

IMO a diesel, especially the 800 lb Duramax is going to be a little bit heavy for a vehicle with a GVW of 3600 lbs. You said it right too when you said it would tear it apart.

Also, AlwayzAMC, if you're looking at the 304 you're not going to have very much hp more than the straight six you have. 210 hp vs. 190 hp. It does have significantly more torque, but it's not like cherokees are lacking in that area. It's not going to bolt up, you'll have to fab engine mounts. The bellhousings aren't the same, you'll have to go with custom headers. There's not enough room between the unirails. And you're probably going to have to do some kind of cowl induction. Some guys have put mustang 5.0's in theirs, but they're not especially more powerfull either. If you go with a late 80's you'll get something around 215 hp.
I was looking at a V8 swap for mine too, but I've decided it's too much work and weight to bother trying to cram one in there. It sounds to me like what you need is a 4.3.

 

[Dr. Dyno]

A 4.3 only puts out 195hp so that's only a small change from the 4.0's output. I have a better idea; rebuild your 4.0 into a stroker. My stroker webpage has some useful info. and some "recipes" that you could follow:

http://www.jeep4.0performance.4mg.com/stroker.html

 

[family XJ]

This link has a V8 in an XJ. You can try to contact this guy and ask him.


http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=6281&item=2448326260

 

[REDXJ4FUN]

A V8 conversion is going to be time consuming and expensive to get it right. A stroker si going to be cheaper and will work very well. heck even if you don't want to stroke it just a good rebuild with a nice cam and header with basice hot roding parts will make the 4.0 come alive. The first Xj I had I had to build the motor and at the time stroker were realy not know about so iI did a clifford cam and such and that thing was wild. Light to light it pissed off many V8s.
Another thing. Why are you against gearing. ofr putting power to the groung it is proble the best bang for the buck expecialy if you going to be putting airlockers in. drop some 4.56 in and it will make you smile

 

[Rockhound]

the Dr. is right and so is RED. unless you just have to have an 8 under your hood, i'd go a much more practical route. i plan to eventually stroke my 4.0 but for now i'm running 7.5" and 33s, 4.56s, no slip in the rear44, borla header, catco highflo cat, dynamax turbo catback, a poweraid tb spacer and a custom cold air intake with a 6" aem cone in the fender and an aem bypass valve up high for those deep water situations. my engine has 175K on it and this provides well more than enough power.
Rockhound

 

[MudDawg]

I like the stroker idea too....go find a 258 (4.2) for the crankshaft core...get a set of Eagle rods (in many cases cheaper than reworked stock rods) a decent cam, headers and find a good machine shop...there is much easily found data on setting up a stroker....just be sure your machinist understands the need for proper deck/quench height...AMC/Jeep blocks are notorious for "close enuff" block deck heights. My block deck was .059 too tall!!!!!!!!

If you just gotta have a smallblock....the tranny/transfer case from a 4.3 S-10 should fit the bill.. if you use a 700-R4 tranny, be sure to use the heavy duty planetaries..TCI is a great place to get tranny parts...Advance adapters has a weld in engine mount kit....just remember...you need strong Fab skills and a place/equipment to do it.

 

[LT1XJ]

I am running an LT1 and 700r4 from a 93 camaro, it iwas an excellent swap. But realize what you are getting into. I've got an LS1 waiting to replace the LT1, just trying to get money together to get it all up and running. Hit me with an email if you want some info.
Dustin

 

[mcconnaughey]

Does anyone know where to get Ford 5.0L engine mounts for the XJ?
Thanks,
Alan

 

[Inisadow]

i don't have any intention of re-gearing my axles, i do plan to tear them apart one day when i put in some air lockers, but until then they will stay sealed, and i like the way this is geared, just lacks a lot of push power at above 45 mph

The I6 is getting tired because you are running 32s with stock gearing. Why not fix the engine up and get it regeared. Unless you feel you have to have a v8....

 

[Arakele]

i never once saw this guy mention if he had the I6 or the 2.5. if you have the 2.5 go get a small block mopar and bolt it in. as far as the 304, im going to assume the 304 will work. i only say this because i vaugly remember the 258 and the 304 transmisions were interchangeable in gremlins. and that 258 would have the exact same pattern as the 4.0. but if i was going that route i would look for an AMC 327 out of an AMX.

 

[alwayzAMC]

thanks all for your imput, i was afraid that the small block conversion would be quite the hassle, i wasn't aware either that the advance adapters was a weld in solution, that is certainly something i want to avoid, the reason i don't want to change the gearing, is because i find the gearing just right as it is, i am just losing my low end power, and i only run into problems on the hills, i have toyed with the idea of the stroker engine, and when the time comes that might be what i will do, i was just hoping there was a simple way to drop in a chevy small block, i didn't think there was, but can't blame a guy for hoping for an open box, install and drive her again solution.,

rebuilding this one, and adding some performance and HP to the engine is probably where i will go with it, i am guessing it will need to be bored out, and a low end torque cam is probably the way i am going to go, any numbers on what i can hope to see from a stroked and decked out 4.0??

 

[Dr. Dyno]

..any numbers on what i can hope to see from a stroked and decked out 4.0??

You'll find some numbers on my stroker webpage. Just choose your recipe.

 

[alwayzAMC]

You'll find some numbers on my stroker webpage. Just choose your recipe.

ok, that 4.9, and 5.0 conversion looks awesome, don't know about the $4,000 dollar investment there, i only bought the rig for $250, have about 1,200 in it so far, including a 3: lift and 32 super swampers, i have a good friend that owns an engine shop, and he can probably put something close to this together for me, can i buy the parts individually anywhere that u know of,

a 300 HP straight 6 would be quite insane :wierd:

 

[dennisuello]

...the reason i don't want to change the gearing, is because i find the gearing just right as it is, i am just losing my low end power, and i only run into problems on the hills...

lower gears would help you nicely on the hills.

is it auto or manual? what axle gearing do you have now?

 

[alwayzAMC]

not too sure on the gearing, it is an 87 4.0 4 speed auto, no towing package, there is a comfort/power switch for the tranny if thats any help

the engine currently has 225,000 miles on it, it is time for something, i am sure i will see 250 out of it, but.... at 45-50 mph on a hill, not sure of the exact speed because of the larger tires, in 3rd gear it chugs along, and drops to second, i know lowering the gearing will help that, but adding more torque will also help, wouldn't lowering my gearing also mower my mpg??