what'll swap into a 84xj with a 2.8 ?

i got a sweet deal (FREE) on a 84xj that needs a motor . what will interchange with a 2.8 v6 ? jeep has auto tranny in it . i just want to get it running to have a spare woods toy .

A popular swap for the 2.8 is the 3.4 Camaro V6. Is it just the engine your wanting to swap, or the trans too?

I guess Chevy 2.8s will swap.

barillms said:

I guess Chevy 2.8s will swap.

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I think something besides a POS 2.8 will.

go with a 4.3 GM.

basically its a reconfigured 2.8 and much more reliable. Parts availablility is HIGH.

With all the accessories, and computer, it whould work well for your application.

Very reliable motor.

How much work do you want? The 4.3 does not hook up to the rest of the drive train without major adapter work. The 3.4 is a direct relpacement in terms of hooking up the tranny. One uses a 60 degree v block, the other a 90 degree v block...don't remember which is which, but the 2.8 and 3.4 are basically the same block. This is why people go with the 3.4 l engine.

red91inWA said:

go with a 4.3 GM.

basically its a reconfigured 2.8 and much more reliable.

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Actually, the 4.3 is basically same as a Chevy Small Block, just missing 2 cylinders. 4.000 bore and 3.48 stroke. The 2.8 is a different design all together.

4.3 is 90 degrees. You'd need the trans to go with it.

3.4 is a 60 degree v6 and would bolt in to motor mounts, trans, etc. with little or no effort.

Putting in a 4.3 requires about the same amount of work as a V8 chevy would.

thanks guys ....i guess i'm looking for a 2.8 or a 3.4 . i just want to get it running using the trans and everything thats there . .

Only the rear wheel drive 2.8 3.4 and the rare 3.1 rear wheel drive will fit.....None of the front wheel drive stuff has the right motor mount holes.

majic_tech said:

Only the rear wheel drive 2.8 3.4 and the rare 3.1 rear wheel drive will fit.....None of the front wheel drive stuff has the right motor mount holes.

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Yep x2

Also I would suggest sticking to the 3.4 from a 90's camaro. They revised the crank bearings to a stronger setup somewhere between the 2.8's and 3.4's. The 3.4's are a much better choice.

You can also buy a new 3.4 set up for carburetion from you chevy dealer. It is designed as a replacement motor for the S10's. But it has about 60 extra horsepower

No carb.......dont do it dude ,go fuel injection ,way more power/milage as per the mad scientist in his domian known to most as "The red beer laboratory"

Don't forget that the 3.1 Gen II and the3.4 genIII cam / bird engines are internaly balanced and the 2.8 is externaly balanced.
The flexplate on the 3.1 and 3.4 are three hole and the torque converter from the 2.8 are four hole.

You will have to use the flexplate from the 2.8 and have it neutrally balanced.
There is no flywheels available that will work with either so you will have to stay with a auto trans.

All the 3.4's I have found are rear wheel drive.
The 3.1 from the 1990-1993 cam/birds are rear wheel drive.
the front wheel drive 3.1's have the starter boss on the left side and you need it on the right.

2.8l 115hp. 3.1l 140hp. 3.4l 170hp. stock
Oh yea if you want to use the carb and manifold from a 2.8 you can I like the fuel injection myself.

Hope this helps
73's KG4BET

yes do the f.i. if it dont have a bunch of complicated electrical devices and wiring it just bores me to tears

red91inWA said:

go with a 4.3 GM.

basically its a reconfigured 2.8 and much more reliable. Parts availablility is HIGH.

With all the accessories, and computer, it whould work well for your application.

Very reliable motor.

Click to expand...

No it isn't. The 3.4 is the improved version of the 2.8. They are both 60-degree V6's. The 4.3 is a shortened SBC V8 -- it's a 90-degree block. It can be shoehorned into the XJ engine room, but it's a tight fit and NONE of the XJ accessories will fit, nor will the tranny.

BTW -- while the 3.4L is the best choice for a V6, don't forget that a Jeep 2.5L will also drop right in and mate up with the tranny. Flexplate balance will be an issue, but flexplates are cheap. If you just need to get it running, a 2.5L produces very nearly the same HP and torque as the 2.8L -- and if you get a 91 or newer with MPFI it actually puts out more than the 2.8L.

I just swapped in a 3.4L from a Camaro. You do need to re-balance the flywheel, I did mine by cutting off the extra weight and drilling holes similar to the Camaro flywheel. It balanced on a wheel balancer to within a 1/4 ounce. I added an in tank fuel pump from a newer XJ (swapped the tank) and put fuel injection from a 2.8 TBI truck on the motor. Had to use a bigger throttle body from a 305 or larger small block with TBI. Doesn't really matter which one. Wiring is straight forward if you get everything from an S-10 or even a full size prior to 90 model year. Oh yeah you have to open the 2.8 intake throttle bores for the larger throttle body. I put a Crane cam in at the same time and it runs good. About 150 pounds lighter than the 4.0L and much more space in the engine compartment.

I got alot of info from S-10.org or something like that. You cannot use the 4.3 with the stock trans. You cannot use a FWD engine, the mounts are in the wrong place. Why use a 3.1L when their is a bigger motor that fits the same!