4.7 V8 Liberty

REKIII · **Posted:** Mon May 21, 2007 12:24 pm

Just to bring this back from the dead.

I have a 4.7HO from my 02 Grand sitting here with a dropped valve (spring craked, dealer has never seen that before) I'm currently putting in the new longblock that I got from a scrap yard, so when I'm done I'll have this complete engine.

I have an 06 3.7 limited Liberty

Anyways.

What are my computer options? I've done most of my modifying to pre OBDII cars so I don't have a lot of experience with the NGC.

I didn't get any computer with the new motor since I didn't need it. I'm sure I could go find an ECU somewhere.

How do I know which trans is in my libby? It is the 4X4 with the full time 4 wheel option.

So, any opinions? I'm doing the swap in my WJ myself, and have modified other cars quite extensively, so my aptitude is not in questions, but I also like to get other thought and info as much as possible so I'm not reinventing the wheel.

Thanks!!

Bob

tjkj2002 · **Posted:** Mon May 21, 2007 12:40 pm

REKIII wrote:

Just to bring this back from the dead.

I have a 4.7HO from my 02 Grand sitting here with a dropped valve (spring craked, dealer has never seen that before) I'm currently putting in the new longblock that I got from a scrap yard, so when I'm done I'll have this complete engine.

I have an 06 3.7 limited Liberty

Anyways.

What are my computer options? I've done most of my modifying to pre OBDII cars so I don't have a lot of experience with the NGC.

I didn't get any computer with the new motor since I didn't need it. I'm sure I could go find an ECU somewhere.

How do I know which trans is in my libby? It is the 4X4 with the full time 4 wheel option.

So, any opinions? I'm doing the swap in my WJ myself, and have modified other cars quite extensively, so my aptitude is not in questions, but I also like to get other thought and info as much as possible so I'm not reinventing the wheel.

Thanks!!

Bob

AS far as the PCM I'm not totally sure but it would be easier to have the PCM and complete wiring harness from the original vehicle so you should have snagged the PCM and wiring harness when you got the engine.The reason for needing the wire harness from the vehicle is you need the wires for the extra 2 injectors and coil packs,the KJ wiring harness will have to well modified(and probally not worth doing) to work with a V-8 PCM and engine.As far as your '06 tranny,it's a 42RLE and probally not strong enough for a 4.7 V-8,a 45RFE from a '02 KJ will handle the extra power though.

REKIII · **Posted:** Mon May 21, 2007 1:46 pm

I have the engine harness, just not the ECU.

That sucks about the trans.

Well, I still want to keep this as an idea, buying the new 4.7 for the WJ set me back a bit so it will take awhile to fix the old 4.7 and then get the trans. Plus my other money pit project.

Thanks for the input though.

Bob

QuestMan · **Posted:** Mon May 21, 2007 3:11 pm

Do it! Do it! Do it!

Love to hear how it turns out.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

REKIII wrote:

I have the engine harness, just not the ECU.

That sucks about the trans.

Well, I still want to keep this as an idea, buying the new 4.7 for the WJ set me back a bit so it will take awhile to fix the old 4.7 and then get the trans. Plus my other money pit project.

Thanks for the input though.

Bob

I know how it feels. I've got a 3.7 short block with 2 scorched cylinders sitting in my garage right now that I'm still trying to decide how to rebuild. Going to be expensive however we rebuild it.

A built 4.7 HO would be really sweet in a KJ. It will be a lot of work, but should be worth it.

Louis Young · **Joined:** Wed Jun 27, 2007 11:21 pm **Posts:** 3

Under an unusual set of circumstances, I happen to have a very, very totaled ‘01 4.7 Dak truck that starts and runs.....I also have a ‘02 Liberty 2WD 3.7 that has dropped a cylinder at 198K miles...(actually maybe two…)..But the body, paint and interior are remarkably clean and serviceable on the Liberty….

Has anyone out there actually done this?? I have both sets of factory service manuals but as you can imagine, that is no help as far as dimensions and such….I wonder if the jump from 210HP & 235 ft lbs to 250HP and 300ft lbs would be worth the time and energy….40 hp and 65 ft-lb’s……Hmmmmmm……

I understand the engine controller and engine harness may plug and play…maybe….Would the hood close?? the accessories and accessory drive looks compatible….I suppose the tranny could just follow the 4.7 right out the front of the dak and into the Liberty as an assembly..….I guess the tailshaft housing is the same ?? ….

Gentlemen….Has anyone actually done this??

unixxx · **Posted:** Thu Jun 28, 2007 2:14 pm

There's no replacement for displacement; throw a supercharger on the 4.7L :twisted:

Louis Young wrote:

I wonder if the jump from 210HP & 235 ft lbs to 250HP and 300ft lbs would be worth the time and energy….40 hp and 65 ft-lb’s……Hmmmmmm……

tjkj2002 · **Posted:** Thu Jun 28, 2007 7:53 pm

unixxx wrote:

There's no replacement for displacement; throw a supercharger on the 4.7L :twisted:

Louis Young wrote:

I wonder if the jump from 210HP & 235 ft lbs to 250HP and 300ft lbs would be worth the time and energy….40 hp and 65 ft-lb’s……Hmmmmmm……

The 4.7 suffers from the same problems with forced induction as the 3.7.Just what for the '08 4.7's,the Dakota version is upped to 290hp and 320lb-ft torque,the Grands get the 305hp and 334lb-ft of torque version.

unixxx · **Posted:** Thu Jun 28, 2007 9:41 pm

I think there's a company making forged pistons for the 3.7L and 4.7L.

Alak · **Posted:** Fri Jun 29, 2007 12:11 am

Theres always a company making forged pistons for something.

I think the tranny will handle it in an 06 I think. Power-wise, putting in this engine is no different than a supercharger kit, etc. Just treat her nice.

I'd be more worried about electronics than if the engine will fit. What about instrument panel (tach, etc.)? How plug and play is it? I would imagine an 02 4.7L computer would fit directly into an 02 KJ. What about 02 to 06, etc?

Just thoughts.

REKIII · **Posted:** Fri Jun 29, 2007 2:21 pm

Louis Young wrote:

Under an unusual set of circumstances, I happen to have a very, very totaled ‘01 4.7 Dak truck that starts and runs.....I also have a ‘02 Liberty 2WD 3.7 that has dropped a cylinder at 198K miles...(actually maybe two…)..But the body, paint and interior are remarkably clean and serviceable on the Liberty….

Has anyone out there actually done this?? I have both sets of factory service manuals but as you can imagine, that is no help as far as dimensions and such….I wonder if the jump from 210HP & 235 ft lbs to 250HP and 300ft lbs would be worth the time and energy….40 hp and 65 ft-lb’s……Hmmmmmm……

I understand the engine controller and engine harness may plug and play…maybe….Would the hood close?? the accessories and accessory drive looks compatible….I suppose the tranny could just follow the 4.7 right out the front of the dak and into the Liberty as an assembly..….I guess the tailshaft housing is the same ?? ….

Gentlemen….Has anyone actually done this??

Where are you located?

Bob

Louis Young · **Joined:** Wed Jun 27, 2007 11:21 pm **Posts:** 3

Located in South Missisippi ....About 70 Miles north of the Gulf Coast.....Yes we still have tarps on many roofs!....

REKIII · **Posted:** Mon Jul 02, 2007 8:58 am

Hmmm, darnit. Was hoping midwest so we might be able to colaborate a bit.

Bob

LiLredLibby · **Posted:** Mon Aug 13, 2007 11:26 pm

Well...the way I'm looking at it is that if you did stuff a V-8 in a libby,the engine swap would probably be the cheap part.I think the biggest cost would be Tranny,both diffs,all new drive axels and drive shaft,and anything that won't even handle big tires,much less a real engine.My guess is that once you got all of the bugs worked out,you would have a 50,000 dollar Libberty.Of coarse I'm speaking of 4x4 transplant,the 2wd might not be that bad.And if all the figures from doing just a SFA are correct(20,000 to 30,000)it might even be more than that.I think I could find a better way to invest 50,000 +. :wink:

Ron

tjkj2002 · **Posted:** Wed Aug 15, 2007 7:57 pm

LiLredLibby wrote:

Well...the way I'm looking at it is that if you did stuff a V-8 in a libby,the engine swap would probably be the cheap part.I think the biggest cost would be Tranny,both diffs,all new drive axels and drive shaft,and anything that won't even handle big tires,much less a real engine.My guess is that once you got all of the bugs worked out,you would have a 50,000 dollar Libberty.Of coarse I'm speaking of 4x4 transplant,the 2wd might not be that bad.And if all the figures from doing just a SFA are correct(20,000 to 30,000)it might even be more than that.I think I could find a better way to invest 50,000 +. :wink:

Ron

The 4.7 V-8 swap is next in line for my KJ after the SFA swap in a few months,and I'm 100% sure my drivetrain will handle the extra power(and then some),plus I have the 45RFE so it will handle the torque of the V-8 better then the 42RLE(really will hold up after I mod the tranny with a better TC and clutches).

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

tjkj2002 wrote:

LiLredLibby wrote:

Well...the way I'm looking at it is that if you did stuff a V-8 in a libby,the engine swap would probably be the cheap part.I think the biggest cost would be Tranny,both diffs,all new drive axels and drive shaft,and anything that won't even handle big tires,much less a real engine.My guess is that once you got all of the bugs worked out,you would have a 50,000 dollar Libberty.Of coarse I'm speaking of 4x4 transplant,the 2wd might not be that bad.And if all the figures from doing just a SFA are correct(20,000 to 30,000)it might even be more than that.I think I could find a better way to invest 50,000 +. :wink:

Ron

The 4.7 V-8 swap is next in line for my KJ after the SFA swap in a few months,and I'm 100% sure my drivetrain will handle the extra power(and then some),plus I have the 45RFE so it will handle the torque of the V-8 better then the 42RLE(really will hold up after I mod the tranny with a better TC and clutches).

I've run around 400 lbs torque with my Libby and the 45RFE with an upgraded torque converter with no problems. It should be no problem to run a 4.7 HO in an '02.

Rush345 · **Posted:** Wed Aug 15, 2007 10:51 pm

OK it's time I put my stupid hat on :!:

My previous ride was a '95 Dodge Dakota 4x4 5.2L with an automatic. My question is the 5.2 or for old farts like me 318 V-8, one of the best motors Mopar ever made. It tore up the front CV's towing burnt up the tranny from I beleive towing by the previous owner. Any way as I understand it this engine was dependable and tried and true. It also had power to beat the band. Is this old school motor with a proven track record just too big for the Libby. As I said I ask this out of ignorance, I'm an old shade tree mechanic and maybe I should just PM Lil Red he knows his stuff. I have seen many up grades through a SCARAB (240 Z with a 327 chevy small block). a buddy in high school took a 396 Rat motor and installed it in a Chevy Vega. I admit this all takes more dollars then sence. You through enough money at anything you can make it work. The SEMA auto show proves it. Just a stupid question for anyone chasing the Horse Power GOD..

Louis Young · **Joined:** Wed Jun 27, 2007 11:21 pm **Posts:** 3

The whole idea I was working out was the fact I had a virtually worthless (market wise) Liberty....(blown motor, but otherwise pretty good shape)....And a freshly rolled 4.7 Dak truck....If you went to the junk yard to buy up all the parts, it would be right on the ragged edge of "not worth it" ...Until you look at any other way to get real power in a Liberty....Price a blower, consider a nitrous kit, look at an "all motor" build on a 3.7.....

Seems to me a very mild 4.7 is still a $3500 (and several LONG weekends) deal.....And you still have a drivetrain that is not overly interested in spitting out parts....(roll bar extra...)

Since this is going to be my eldest sons first ride...we are going to find a junkyard 3.7 and let him tear that up first....(anyone have one that is not hurt ??)....Then we may get froggie and pull the whole front end off and see how tough it will be....

tjkoen01 · **Posted:** Mon Oct 20, 2008 8:48 pm

so is anyone still working on this? if you had already have a 45RFE in the Liberty and a doner vehicle, is the ECU plug and play? i'd be willing to bet it would be, however i have know way to find out.

KJ kyle · **Posted:** Wed Dec 24, 2008 4:08 am

Im going to the casino after christmas, and if i hit anything upwards of 5g's i promise ill be the gineu pig. we can have a midwest engine swap party, everyones invited!

4.7 V8 Liberty

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