Hoping to be the first KJ w/ V8

[SavageSS27]

Ok guys, i got a big one for ya. I got this crazy idea in my head a while ago to toss a 4.7L V8 under the hood of our favorite little Jeep. I heard some rumors that DC had shoehorned one in there for testing, but didn't like the crash-test results, being as i'm not planning on ramming into anything at hig speed, i'm not as concerned about that as they might be. Here's the task. If any of you guys have any helpful know-how, parts, time or even just a spare hand, i'd appreciate some help on this. I'm looking for a 4.7L V8, preferably in running condition, but not a necessity. It doesn't need to be from a Jeep, or have accessories on it, but i would like to get it with the PCM and wiring harness if possible, and i don't want to put out an arm and a leg for it. It's gotta be a 4.7L (HO or standard) from a Dodge or Jeep truck, both the Magnum and Powertech V8s are the same (IIRC). So if anyone has some leads on where to get one, has one in their front lawn, or can help with all the figuring that will have to go into getting this thing under my hood I'd greatly appreciate it. I've already been talking to the boys over at LOST and have learned a great deal, I'll leave a link here so you can see what we've discussed already. I'm planning to do this at school (WyoTech) when i go this coming September, and i promise to give you guys as many pics, videos and write-ups as i can. I'm also gonna try to re-do the exhaust that's under the KJ now to get t ready for the bigger mill. I figure two 2.5" pipes comming right off the down-tubes ought to do the trick. I'll make sure to put that all up in a thread too, hopefully i'll have that in the works this summer.




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[Marlon_JB2]

Well unless that guy running around here with a 5.2L powered Liberty is true... yours would be the first (known) V8 powered KJ.

 

[JeepJeepster]

Have you ever thought about building the 3.7L?

You can get new cams, throttle body, Exhaust headers(soon), forged pistons and rods.. Get a new torque converter, shift kit for the 45rfe, get the computer reprogrammed by B&G chrysler..

You could probably be up there with a stock 4.7L then..

 

[SavageSS27]

Yeah, i had thought about it, but i plan on doing the same things, if not more to the 4.7, I'm looking to be in the 450-500HP range.

 

[JeepJeepster]

ohh wow! Do you plan on using the 45rfe? Be sure to do some work to it also if thats what you go with.. A new torque and shift kit will help..

 

[SavageSS27]

yeah, i figure it should be alright with a new TC and a shift kit, if not, i'll see if i can't squeeze something else in there.

 

[04Liberty]

Yeah, i had thought about it, but i plan on doing the same things, if not more to the 4.7, I'm looking to be in the 450-500HP range.

Out of a 4.7? I'm guessing a blower is in the works with it? The 3.7 and 4.7 are from the same family.

Although...if they can shoehorn a 5.7 hemi into a Nitro, then I'm pretty sure the hemi will fit in a Liberty.

 

[SnowgodCCR]

You can also get a crate motor straight from Mopar, I think it's the 5.7 but I could be wrong. There's no replacement for displacement!

Edit: Yes, it's the 5.7, but they also have a few carbourated ones avaliable, from the 426 all the way up to 600 something ci...460-900+ HP [-o< . The 5.7 should fit into the KJ without much muscling needed. Good luck!

 

[SavageSS27]

Yeah, i was definitely thinking about throwing a supercharger on there, IMO, nothing beats that supercharger whine, only problem is, i can't find anyone who still makes a roots or twin-screw style blower for the 4.7. I know Kenne Bell used to make one, but i can't seem to find it. The 5.7 would be NASTY to have under the hood of the KJ, I'm just not sure it'll fit. Besides, i think the 4.7 is really all the motor that the KJ needs. Anything over 500HP and i think it'd be a handful to drive. Not to mention, i'd like to keep the factory ****** and transfer case in there for as long as i can, or until someone donates a new one [-o< . I'm still trying to do some research on the respective sizes of the 3.7, 4.7 and 5.7. If the 5.7 will fit, then i'll go with it for sure. As SnowgodCCR said, "There's no replacement for displacement." and i'm a die-hard believer in that. Besides, the more cubes you have, the more reliable "X" amount of horsepower will be. For example, to get 500HP out of a 4.7 and a 5.7, you'll have to push the 4.7 much harder, and thus be more likely to have issues with it, so if i can feasibly go with a larger engine, i most certainly will. It all depends on what exactly will fit under the hood.

 

[CRD4Liberty]

There must be a SFA in your future or the ******, TC are a mute point.

 

[SavageSS27]

Yeah, an SFA is definitely on the to-do list, but it's a little further down the road. The way i see it, i'll swap in whatever V8 will fit, this will allow me to get some sponsors, with that money, i'll upgrade the V8, and throw a solid axle under the rig. Seems like a good plan now, but i guess we'll see how it works out. I plan on doing it no matter what, cash-flow will determine when.