Jeep 2.5 to 4.0 swap, cummins 4BT?

heepiejeepie

New Member
I have a 2000 TJ with the 2.5 four cylinder engine and overall, have been happy with its performance. I'm now looking at different options to either wake this one up a bit or just swap in a 4.0. There are rumors of a stroker kit for the 2.5 online, but I can't seem to find one. I hear there is also a turbo kit for this engine, but are any of these upgrades worth the time and money??! Is there anyone out there who has swapped their 2.5 for the 4.0? If so, drop me a line and let me know how it went. I'm thinking it should be a pretty strait forward swap. One other swap I've been considering is the cummins 4BT. I know that swap will require a lot of modifications, but it sure is cool! Does anyone have any experience with the 4BT?*
 

Tacoma

Et incurventur ante non
Location
far enough away
The 4bt is a tall engine, that shakes. A LOT. How much? Enough that they engineered special fluid-filled damping mounts for it, and also engineered a counter-shaft on some of them to try and mitigate the vibrations. In addition, they have a relatively narrow powerband, weigh more than a big block, and don't make that much power without a bunch of mods. But, they are a cool engine. :D

The 4.0 is probably the smart money here.
 

rholbrook

Well-Known Member
Location
Kaysville, Ut
A better swap for the money would be either a Chevy LS or a 5.9 out of a Durango. It will be just as expensive to put a 4.0 in. Your transmission and tranfercase (input shaft) will need to be swapped out, motor mounts, computer, etc..
 

RockChucker

Well-Known Member
Location
Highland
i am getting ready to put a 5.3 in my TJ and my 4.0 will be up for sale. PM me if you are interested and we can work something out.
 

MikeGyver

UtahWeld.com
Location
Arem
lol 4bt. One of the worst possible engine swaps in almost every way, yet so many people think its a good idea.
 

thenag

Registered User
Location
Kearns
lol 4bt. One of the worst possible engine swaps in almost every way, yet so many people think its a good idea.

Any other reasons that previously mentioned? Just curious, I know a lot of people put them in full size trucks and seem to be happy with them.



I think a 4bt in a small jeep is probably not the best way to go for reasons listed, weight, number of mods, size, vibration, emissions, the list goes on.

Nathan
99xj
 

MikeGyver

UtahWeld.com
Location
Arem
Compared to a V8 like say a GM 5.3L - 6.0L (LS family, etc)

they're much heavier, ruins your vehicles weight distribution
makes much less power and torque
doesn't rev
has a narrow powerband
requires lots of gears
much worse drivability
much much more expensive
parts are harder to get
turns your vehicle into a paintshaker
is almost certainly less fuel efficient
diesel usually costs more than gas anyway...

Unless I'm overlooking something there's literally no single aspect that is better except maybe novelty factor, I mean just look at the area under the curve (actualy power since peak alone doesn't mean much), there's simply no comparison whatsoever to a motor you can easily find for $500.


torquecurve3.png



LQ4 6.0L

GTODynoGraph-1.jpg
 
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