4.7 V8 II into My KJ

[blue_kjR417]

Ok, I know everyone probably at one time has thought about this but I'm really interested in possibly trying this! I think the 4.7 V8 II from the 2008-Up Dodge Dakota/Jeep Grand Cherokee/Dodge Durango would be perfect to throw in a KJ and I found that the 09 Grand Cherokee's are available with either the 3.7 V6 from the Liberty's or the 4.7 V8. Therefore the engine mounts must have to be the same correct? Which means one should drop into a KJ. Now I know I've have to either swap computers or reconfigure mine or something. However, would the stock ****** in my KJ hold the 300+ hp from the 4.7? If so thats awesome! But do you guys think the thing would even fit? Here are some pics of the 4.7 V8 in a 2008 Dakota and Grand Cherokee.

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305 hp / 334 lb-ft torque

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[Signe]

The stock ****** in my '03 KJ is an 45RFE. IIRC, Jeep used more than one type of automatic ****** on KJ's and the one I've got is considered the better one because it's the same ****** Dodge uses in some of their pickup's (and is therefore stronger.) Find out which ****** you've got and then ask the dealership what other Dodge/Jeep vehicles use it. If it's used on trucks/SUV's with a 4.7L, then you will probably be okay. If you give the dealership your VIN #, they should be able to tell you which ****** you've got.

You're talking about a big job here. I don't discourage anybody from doing things like this, but although it certainly might be doable, you're likely to run into issues you weren't expecting.

I also ride motorcycles. I once read about this mechanic that swapped an engine from a 5th generation ('98 - ' 01) Honda VFR to a 6th generation ('02 - present) Honda VFR. The bottom line is while the swap was successful, he ran into a lot of little problems he wasn't expecting (and keep in mind, the engines were identical in size and power output.) He was able to resolve all the issues that came up, but the swap took him a lot longer to do than he thought.

 

[BMR]

Man, I hope you figure out what you need to know to get yourself into this project. It'd be freaking sweet if it ends up working out. I wish you luck!

I also ride motorcycles. I once read about this mechanic that swapped an engine from a 5th generation ('98 - ' 01) Honda VFR to a 6th generation ('02 - present) Honda VFR. The bottom line is while the swap was successful, he ran into a lot of little problems he wasn't expecting (and keep in mind, the engines were identical in size and power output.) He was able to resolve all the issues that came up, but the swap took him a lot longer to do than he thought.

Lotta work just to get the VTEC!

 

[Marlon_JB2]

Not easily possible in a 2005. You'd need a new transmission too. The 42RLE isn't strong enough for the torque from the 4.7L V8. This has been researched to death, is certainly possible, and do-able easily and cheap....... with a 2002-2003 KJ with the 45RFE transmission.

 

[Signe]

IIRC, he did the swap because he wanted gear-driven cams and didn't care for the VTEC. I've got a VTEC myself and if it were up to me, all 16 valves would be operational at all times. However, the 6th generation VFR looks a heck of a lot better than the dated-looking 5th generation.

 

[MKay]

burnsville can put a 6.1v8hemi in a kj so im sure they could help

 

[tjkj2002]

burnsville can put a 6.1v8hemi in a kj so im sure they could help

You mean JK.

 

[LibertyFever]

OMG , I can't even imagine a V8 in a Libby.

Realistically you've have to consider swapping out the entire drivetrain. Something within the stock transmission, transfer case and axles would simply snap the first time you hit the "go" pedal Also I don't think the Dana 30A axle would support the extra weight. You'd have to include a SFA too.

LOL, remember what Jeep stands for; Just Empty Every Pocket

 

[tjkj2002]

OMG , I can't even imagine a V8 in a Libby.

Realistically you've have to consider swapping out the entire drivetrain. Something within the stock transmission, transfer case and axles would simply snap the first time you hit the "go" pedal Also I don't think the Dana 30A axle would support the extra weight. You'd have to include a SFA too.

LOL, remember what Jeep stands for; Just Empty Every Pocket

The D30A does not support any weight in the KJ,the whole idea with IFS.

The 45RFE ****** which is found on '02's and some '03 KJ's will handle the 4.7,and is 100% compatible,any of the t-cases will handle the 4.7,and the 8.25 rear diff will also handle the 4.7 in stock trim(Dakota/Durango/Grand Cherokee has the 4.7 with 8.25 rear diff).




The motor mounts are the same,and in the same location between the 3.7 and 4.7.All the accesories will bolt on from the 3.7 to the 4.7.There is room in the KJ's engine bay for the 4.7,a custom radiator and ultra slim electric fan will be needed.The KJ at one point did have the 4.7 installed(as a prototype only) but was axed due to poor front end crash tests,basically they could not keep the engine from pushing into the cabin in front end crashes.The electronics would be easy,unless you have ABS/ESP and the OEM alarm systems.You will need a new wiring harness(engine) so it would be better suited to find a '99-'03 Grand Cherokee for a donor vehicle(heavy rear wrecked?) for all that stuff.This swap is in the future for my KJ,after the SFA swap.I have talked to Dan at Burnsville Offroad a few times about it and he will be doing the work after I gather all the parts and money(2010?).












Oh and don't even think about the 5.7/6.1/6.4/7.0 HEMI's,they will not fit,and the amount of cutting required to make them fit would render your KJ as a non-driveable trailer qween.

 

[sean150]

I'm interested to see you do it that is for sure. If i'm not mistaken hasn't this been discussed many times on both KJ Country and the Lost KJ forum but no one has actually done it? One thing is for sure if you get one in then your KJ will become a whole different vehicle for you.

 

[Marlon_JB2]

There's a rumor, that's been floating around since at least 2004 that there's at least one V8 KJ running around but it's not the 4.7L... it's the old 5.2L Mopar V8.

 

[KYLiberty]

I don't think that rumor is actually true. I've met a couple people who claimed to have seen it after seeing mine when it was racing, but after only a few questions it was pretty obvious they were full of it. The rumor popped up around the same time as we put the N2O on mine which was right after we seriously discussed dropping a 4.7 in it because KB had told me they didn't think they would ever make the supercharger kit for it. We knew how to fit the 4.7 in it that was just sitting there looking so pretty, but I hadn't hooked up with B&G yet and we weren't sure if we could get the computer to work. We were also a little worried about it not dropping in a head on collision. I also would have been a little upset if I had the KJ torn apart for a month or two and it didn't work.

 

[Marlon_JB2]

I don't think that rumor is actually true. I've met a couple people who claimed to have seen it after seeing mine when it was racing, but after only a few questions it was pretty obvious they were full of it. The rumor popped up around the same time as we put the N2O on mine which was right after we seriously discussed dropping a 4.7 in it because KB had told me they didn't think they would ever make the supercharger kit for it. We knew how to fit the 4.7 in it that was just sitting there looking so pretty, but I hadn't hooked up with B&G yet and we weren't sure if we could get the computer to work. We were also a little worried about it not dropping in a head on collision. I also would have been a little upset if I had the KJ torn apart for a month or two and it didn't work.

And that's why it still is, and always be a rumor...

At least until pics and video show up.

 

[MKay]

actualy they will put it in a kj as well i have been in touch with dan, thats my intention when the SFA kits are ready.

 

[04Liberty]

OMG , I can't even imagine a V8 in a Libby.

Realistically you've have to consider swapping out the entire drivetrain. Something within the stock transmission, transfer case and axles would simply snap the first time you hit the "go" pedal Also I don't think the Dana 30A axle would support the extra weight. You'd have to include a SFA too.

LOL, remember what Jeep stands for; Just Empty Every Pocket

Not that much of a stretch from the 3.7 to a 4.7, just a little longer, they're brothers.

The D30A does not support any weight in the KJ,the whole idea with IFS.

The 45RFE ****** which is found on '02's and some '03 KJ's will handle the 4.7,and is 100% compatible,any of the t-cases will handle the 4.7,and the 8.25 rear diff will also handle the 4.7 in stock trim(Dakota/Durango/Grand Cherokee has the 4.7 with 8.25 rear diff).




The motor mounts are the same,and in the same location between the 3.7 and 4.7.All the accesories will bolt on from the 3.7 to the 4.7.There is room in the KJ's engine bay for the 4.7,a custom radiator and ultra slim electric fan will be needed.The KJ at one point did have the 4.7 installed(as a prototype only) but was axed due to poor front end crash tests,basically they could not keep the engine from pushing into the cabin in front end crashes.The electronics would be easy,unless you have ABS/ESP and the OEM alarm systems.You will need a new wiring harness(engine) so it would be better suited to find a '99-'03 Grand Cherokee for a donor vehicle(heavy rear wrecked?) for all that stuff.This swap is in the future for my KJ,after the SFA swap.I have talked to Dan at Burnsville Offroad a few times about it and he will be doing the work after I gather all the parts and money(2010?).



Oh and don't even think about the 5.7/6.1/6.4/7.0 HEMI's,they will not fit,and the amount of cutting required to make them fit would render your KJ as a non-driveable trailer qween.

Unless you have an 08 and up. The factory made one work for a SEMA show in a Nitro (just a 5.7).

 

[MiniDevil]

How much for a new 4.7? I havent seen any for sale.

 

[Robocody]

A find for anyone in NY who wants to do this...

http://buffalo.craigslist.org/cto/991724155.html