2.5L to 2.8L swap?

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bigoltrux77

NAXJA Forum User

Location

Milwaukee, WI

• Sep 8, 2003

• #1

I have a good deal on a 2.8L engine. I know its no 4.0 but from what ive heard, that swap is a bitch to complete. Id like to swap out my crap 2.5L for a crap 2.8L. Anything good about this swap? Can i use my stock AX-5 and np207 combo? Anything i need to modify? Any other sugestions? I know about a chevy v6 swap, what engine is it exactly? What tranny/tcase combo would i need? How do i go about doing that swap? Thanks alot.

 

Eagle

Lifetime NAXJA Member

NAXJA Member

Location

Terra Firma

• Sep 8, 2003

• #2

The 2.8L hardly puts out any more power than your 2.5L, and is unreliable on top of that. Actually, it IS reliable -- you can rely on it to blow up. If the 2.8L is your only option, you'll do far better to stick with the 4-banger.

The GM engines that will drop in to replace the 2.8L (and thus the 2.5L) are the 3.1L and 3.4L V-6s from rear wheel drive cars and S-10 trucks. GM also sells a 3.4L crate engine specifically to replace the 2.8L in S-10s, and that engine will also drop right into an XJ. Bell housing bolt pattern is the same as your 2.5L so you can run the same tranny and transfer case you already have.

 

CheapXJ

NAXJA Forum User

Location

570, 813 or 303

• Sep 8, 2003

• #3

what year is your Jeep?

if it's 87 or newer, the swap is a simple remove and replace (for the ENTIRE drivetrain) and can be done in a week.

there is a TON of stuff that needs to be changed, but it's pretty straightforward. I just did this on my 87 MJ (used a cherokee as the parts donor) and it wasn't very hard.

it IS possible on an 84-86, but you do need to do some sheetmetal modification (the radiator core support and hood/lateches need to be changed, this requires welding) and the firewall needs to be bent in at the very back to clear the exhaust manifold and allow room for wiring.

 

R

rixXJphx

NAXJA Forum User

Location

phoenix

• Sep 8, 2003

• #4

If you decide to go with the 2.8 (against all advice and common sense ), beware that there are TWO versions: FWD and RWD/4wd.

The FWD came from Citations and the like, and will NOT fit in a RWD application owing to the starter being on the wrong side.

 

Ghost

Member Number 257

NAXJA Member

Location

Hartsville, South Carolina

• Sep 8, 2003

• #5

Find a newer 2.5 the 2.8's were barely good enough for boat anchors. What year is your 2.5?

 

sidriptide

nobody of any consequence

Location

western massachusetts

• Sep 8, 2003

• #6

another vote against the 2.8.... very long, well documented, bad histroy of rear main seal failure.... i don't know actual specs but having owned both engine i say the 2.8 has less low end power/torque (where you need it most) 4.0 will be more work than it's worth (if its a pre-87 XJ).. 3.4L is my vote.. i havent looked into it but i'd consider a 4.3 V6 TBI swap from a blazer...
mike

 

Georgia Mike

NAXJA Forum User

Location

Flowery Branch,GA

• Sep 8, 2003

• #7

:laugh: A 2.8 :roflmao:

Sorry. The 2.5 has more "real-world" hop-up potential (I know XJGuy is gonna jump me for this one-but blowers and nitrous aren't real-world anyway ) than the 2.8 has,IMHO. Freshen up the 4 popper with a rebuild,valve job,put in a hotter cam,a good header with free-flowing exhaust,and a cool air intake and you'll kick your own ass for ever thinking of putting a 2.8 in your rig. I was there once,young Skywalker,and I saw the light! I actually contemplated swapping a 2.5 into my rig to replace that crappy 2.8! :thumbup:

 

Ghost

Member Number 257

NAXJA Member

Location

Hartsville, South Carolina

• Sep 8, 2003

• #8

Ahh the voice of experience! Even though he is a traitor! For selling a perfectly good trail rig! LOL!

 

B

bigoltrux77

NAXJA Forum User

Location

Milwaukee, WI

• Sep 8, 2003

• #9

OK OK, no 2.8L i understand. Well i have a deal on a whole load of rebuild parts for my 4 banger. The guy wants 800 bucks for this stuff shipped to my door. It includes performance-pistons, rings, rods, rebuilt head to match perf. cam, ported intake manifold, rebuilt carb, deep sump oil pan, hiflo fuel and oil pump, and other rebuild parts id need. Does this sound ok?

 

H

HossHoffer

NAXJA Forum User

Location

Aurora, CO

• Sep 8, 2003

• #10

Fine

That should about cover the rebuild. In fact that would be a great rebuild. Which perf carb is included with it? I got rid of my carb and installed the newer model tbi. The wiring wasn't that tough and the throttle response is much better although a good carb will do just as well. I have a similar rebuild on my '85 and the torque increased dramatically. I towed a small utility trailer over the rockies and scooted right along. I also have a 2.8l and although it runs better on the road it sucks on the trail and I am stroking out a 4.0l now and will install it and a complete drivetrain into the 2.8l. Oh and by the way, I still get about 21 mpg around town and over 25 mpg on the highway with my 4 banger.

 

Georgia Mike

NAXJA Forum User

Location

Flowery Branch,GA

• Sep 9, 2003

• #11

Ghost said:

Ahh the voice of experience! Even though he is a traitor! For selling a perfectly good trail rig! LOL!

Click to expand...

It ain't over yet :looser: The ole girl is still in the driveway begging me not to sell her,and I think I'm starting to listen to 'er............:laugh:

 

Ghost

Member Number 257

NAXJA Member

Location

Hartsville, South Carolina

• Sep 9, 2003

• #12

YEEEEHAAAWWW!