V8 engine swap

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Blueridge

New Member
Joined
Aug 4, 2013
Messages
19
Reaction score
0
Location
Virginia
Has anyone done a engine swap from 3.7 to V8? I am thinking about doing this but not sure if there is a viable option out there?? Not sure if the drive train would handle the torque?
 

dude1116

Full Access Member
Joined
May 31, 2011
Messages
3,373
Reaction score
13
Location
Pompton Plains, NJ
Has anyone done a engine swap from 3.7 to V8? I am thinking about doing this but not sure if there is a viable option out there?? Not sure if the drive train would handle the torque?

Been done but strangely the people that have done it haven't stuck around for long. You need an '02 or '03 with a 45RFE to handle the torque, so you're already not able to do it with your KJ.
 

Blueridge

New Member
Joined
Aug 4, 2013
Messages
19
Reaction score
0
Location
Virginia
OK thanks. Any suggestions for added HP? Since my lift and bigger tires and weight I got nothing anymore! I need a safe way to add the HP since I have 125K on the 3.7 now.
 

tommudd

Moderator
Staff member
Moderator
Joined
Jul 14, 2005
Messages
22,456
Reaction score
3,642
Location
Southeastern Ohio
simple answer is .........

regear to 4.10s makes a big difference
and throw the CAI in the dumpster

by the way what do you measure from middle of the wheel to bottom of the flare
 
Last edited:

LetFreedomRing

Full Access Member
Joined
Jul 1, 2010
Messages
292
Reaction score
1
Location
Pennsylvania
You could also try a hypertech programmer. It seems to get favorable reviews from the ones who actually tried it with the 3.7 engine... :emotions33:

24hp/24tq claims. The WK crowd loves it.
 
Last edited:

VAhlene

Full Access Member
Joined
Apr 12, 2013
Messages
411
Reaction score
0
Location
Castle Rock, CO
Not sure if this one is still around but this guy put a 4.7 in his KJ. I think there is another longer video but I couldn't find it.
[YT]Aygwn2A3bAo[/YT]
 

tommudd

Moderator
Staff member
Moderator
Joined
Jul 14, 2005
Messages
22,456
Reaction score
3,642
Location
Southeastern Ohio
So far everyone who has done a V8 and posted on line it seems traded/sold/gave away or disposed of them in a very short time .
Love the hot air suckers on that video , worst place ever to draw in air
 

u2slow

Full Access Member
Joined
Mar 6, 2012
Messages
656
Reaction score
107
Location
BC
ummm... didn't V8 Dakota's use similar drivetrain? Dodge 318 probably has as much (or more?) low-end torque as the 4.7L.
 

kj04libby

Full Access Member
Joined
May 4, 2013
Messages
309
Reaction score
0
Location
Tuscumbia, AL
I'm actually in the process of swapping a Chevy 350 with a 350 turbo trans now. Advance Adapters part No. 50-6302 is making it all possible. Just have to weld up engine mounts. Getting rid of the fuel injection makes it easier. BTW if anyone needs any parts let me know everything except the engine is good.
 

u2slow

Full Access Member
Joined
Mar 6, 2012
Messages
656
Reaction score
107
Location
BC
I'm actually in the process of swapping a Chevy 350 with a 350 turbo trans now.

Good to see somebody thinking outside the box! I'll probably convert mine to diesel someday... a mechanical one that is. :D
 

JeepCoMJ

Full Access Member
Joined
Nov 29, 2010
Messages
629
Reaction score
10
Location
SE WI
OP, look through my threads and you'll find some pictures of what one looks like mocked up in the engine bay. Mounts are going to have to be custom...would be easier to modify the suspension subframe motor mounts to fit the v8 mounts than the other way around. KJ motor mounts will not bolt up to the v8, do not even come close to being modifiable to do so.

The swap itself is bolt-in to the transmission....if you have a 45RFE or upgrade to a 5/45RFE. You cannot swap to this trans with a mid 03 and newer, it will not work with the hybrid can-bus/PCI system. The work necessary to accomplish that would negate any benefit from the swap, and leave you in a position where you're better off to just buy a grand cherokee.

I was hot on doing this swap until it seemed more and more people were going to be doing it. I want what others don't have, not to be part of the crowd.


A KJ isn't worth the engine swap. It just isn't. Time and effort with compatibility issues vs value of the vehicle before swap and after swap (the swap will decrease value to anyone who is leary of other people's "custom" work and increase it to mentally insecure yuppies who see V8 and wet themselves) negates the gain of the swap.


There are plenty of things you can do to gain power back. regear, multiple hole spray pattern injectors, open up the exhaust a bit, bored throttle body. There is seemingly zero aftermarket support for engine internals.

I'm actually in the process of swapping a Chevy 350 with a 350 turbo trans now. Advance Adapters part No. 50-6302 is making it all possible. Just have to weld up engine mounts. Getting rid of the fuel injection makes it easier. BTW if anyone needs any parts let me know everything except the engine is good.

....

getting rid of the fuel injection on an 02 vehicle? you will not pass inspection, you will not pass emissions/smog, you will not be able to drive it offroad on inclines, and you will get absolute crap mileage compared to what you could get with fuel injection. Not to mention, if your block is older than the vehicle then the swap is actually illegal in most states.

going with the 350 will elminate most options that the KJ has...real time fuel mileage is now impossible using stock parts. gauges will no longer function (they are run by signal from BCM, which picks up signal from PCM, which are going to be expensive to replicate and adapt off of the 350). As for aftermarket gauges, now you have lost your entire instrument panel. accurate miles on vehicle, 4x4 indicators, etc. are going to be impossible to make look OEM, or even make look good.
 

jankerson

Full Access Member
Joined
Sep 13, 2013
Messages
77
Reaction score
0
Location
Raleigh, NC
I think it would be better and cheaper in the long run to have the 3.7L rebuilt and modified for more performance. That or get a 3.7L crate engine from Mopar and have that one built.

The only concern then would be if the transmission and the other drive train parts could handle the increased torque over stock.

At least it would be reliable and everything would work once it was done.... That is if it was done by people who know what they are doing....

It wouldn't be cheap though....
 
Last edited:

kj04libby

Full Access Member
Joined
May 4, 2013
Messages
309
Reaction score
0
Location
Tuscumbia, AL
I was hot on doing this swap until it seemed more and more people were going to be doing it.
....

getting rid of the fuel injection on an 02 vehicle? you will not pass inspection, you will not pass emissions/smog, you will not be able to drive it offroad on inclines, and you will get absolute crap mileage compared to what you could get with fuel injection. Not to mention, if your block is older than the vehicle then the swap is actually illegal in most states.

going with the 350 will elminate most options that the KJ has...real time fuel mileage is now impossible using stock parts. gauges will no longer function (they are run by signal from BCM, which picks up signal from PCM, which are going to be expensive to replicate and adapt off of the 350). As for aftermarket gauges, now you have lost your entire instrument panel. accurate miles on vehicle, 4x4 indicators, etc. are going to be impossible to make look OEM, or even make look good.

1. The whole reason you stopped doing your swap is because everyone was doing it. No one has followed through with a swap like this. I will. 2. I don't have inspections. 3. All my buddies carburated trucks and crawlers do fine on inclines. I'm aware I couldn't rock climb for long but oh wait it IFS so not doing that magnitude of crawling. 4. Any swap in any vehicle of any year legal in Alabama. 5. I never had real time MPG don't care to on a toy. 6. I had no clue my gauges wouldn't work... Lol wait, yeah I did that's why I planned on putting brushed aluminum where the old one went and placing my speedometer, tach, and fuel gauge (already have the volts, temp, and oil in my a pillar) 7. It will look good. Not stock but good(and after it has a 350 I don't care if it looks stock or not(who needs a light telling me what I'm in if I have a lever that operates my 4x4 with a cable...)) I don't understand what's peoples problem with ME doing what I WANT with MY vehicle. I promise I've thought every thing through and for the complications I haven't I'll conquer them when I get to them.

Thanks!
 

jankerson

Full Access Member
Joined
Sep 13, 2013
Messages
77
Reaction score
0
Location
Raleigh, NC
1. The whole reason you stopped doing your swap is because everyone was doing it. No one has followed through with a swap like this. I will. 2. I don't have inspections. 3. All my buddies carburated trucks and crawlers do fine on inclines. I'm aware I couldn't rock climb for long but oh wait it IFS so not doing that magnitude of crawling. 4. Any swap in any vehicle of any year legal in Alabama. 5. I never had real time MPG don't care to on a toy. 6. I had no clue my gauges wouldn't work... Lol wait, yeah I did that's why I planned on putting brushed aluminum where the old one went and placing my speedometer, tach, and fuel gauge (already have the volts, temp, and oil in my a pillar) 7. It will look good. Not stock but good(and after it has a 350 I don't care if it looks stock or not(who needs a light telling me what I'm in if I have a lever that operates my 4x4 with a cable...)) I don't understand what's peoples problem with ME doing what I WANT with MY vehicle. I promise I've thought every thing through and for the complications I haven't I'll conquer them when I get to them.

Thanks!


Well taking all of that into consideration why not just drop a Built 360 Crate motor in there? :peace:
 

Josh

Full Access Member
Joined
Dec 26, 2011
Messages
113
Reaction score
1
Location
Holland, Michigan
I think it would be better and cheaper in the long run to have the 3.7L rebuilt and modified for more performance. That or get a 3.7L crate engine from Mopar and have that one built.

The only concern then would be if the transmission and the other drive train parts could handle the increased torque over stock.

At least it would be reliable and everything would work once it was done.... That is if it was done by people who know what they are doing....

It wouldn't be cheap though....

Good luck:
http://www.jeepkj.com/forum/f196/turbo-charge-53509/
 

Josh

Full Access Member
Joined
Dec 26, 2011
Messages
113
Reaction score
1
Location
Holland, Michigan
I was hot on doing this swap until it seemed more and more people were going to be doing it. I want what others don't have, not to be part of the crowd.

Crowd? Did I miss something? One other in the works and one done, video posted and disappeared.
 

kj04libby

Full Access Member
Joined
May 4, 2013
Messages
309
Reaction score
0
Location
Tuscumbia, AL
Well taking all of that into consideration why not just drop a Built 360 Crate motor in there? :peace:

Because I had a 350 pretty much on hand lol and I can afford this swap at right under a grand( half of that being the adapter to make the 350 turbo trans work with our tcase) but I can't afford any type of crate anything lol
 

Latest posts

Members online

Top